Biology New Information Flashcards

Question

Explain the Rf factor in blood

Answer 1

* is another antigen that may be present on the surface of red bloood cells * Rh + = possesing the Rh antigen * Rh - = lack the Rh antigen

Answer 2

* An Rh- woman can be sensitized by an Rh+ fetus if fetal red blood cells (which will have the Rf factor) enter maternal circulation during birth * If this women subsequently carries another Rh+ fetus, the anti-Rh antibodies she produced when sensitized by the first birth may cross the placenta and destroy fetal red blood cells = **_erythroblastosis fetalis_** **= severe anemia in the fetus** * not caused by anti - A and anti - B because they cannot cross the placenta * **_Rhogam_** is a drug compreised of a mixture of anibodies **given to mothers who are Rh-** to prevent their immune system from attacking the fetal red blood cells

Answer 3

* **_Transport of Gases:_** * Erythrocytes transport O2 throughout the circulatory system * Hemoglobin in erythrocytes bind to O2 * 1 hemoglobin = 4 oxygens because of the iron * Hemoglobin also binds to CO2 - carbaminohemoglobin * **_Transport of nutrients and waste_** * Amino acids and simple sugars are absorbed into bloodstream at the intestinal capillaries * Throughout the body, metabolic waste products (water, urea, and CO2) diffuse into capillaries from surrounding cells, deliverd to appropriate excretory organs * **_Clotting_** * When **platelets come into contact with the exposed collagen of a damaged vessel**, they **release a chemical** that causes neighboring platelets to adhere to one another = **_platelet plug_** * Both the platelets and the damaged tissue **release the clotting factor _thromboplastin_,** which **aid of its cofactors calcium and vitiamin K,** converts the inactive plasma protein **_prothrombin**_ to its active for, _**thrombin_** * Thrombin converts **_fibrinogen**_ (another plasma protein) into _**fibrin_** * **Threads of fibrin coat the damaged area and trap blood cells to form a clot** * Fluid left after the clotting is called **_serum_**

Answer 4

Nose, pharynx (throat), larynx, trachea, bronchi, bronchioles and alveoli

Answer 5

in very thin walls of the alveoli which ar air-filled sacs at the terminals of the airway branches

Answer 6

* Air over the vocal cords for the production of sound * assists in the regulation of body pH by regulating he rate of carbon dioxide removal from the blood

Answer 7

* **_Inhalation_** = **diaphram contracts and flattens**, and the external intercostal muscles contract, pushing the rib cage and chest wall up and out * Phrenic nerve innervates the diaphram causing contraction and flattening * action - **thoracic cavity to increase volume** * reduces pressure, lungs expand * **_Exhalation_** = passive process. Lungs and chest walls are highly elastic and tend to recoil to their original position after inhalation * Diaphragm and external intercostal muscles relax and chest wall pushed inward * **decreasing thoracic cavity volume, pressure increases**

Answer 8

* Surfactant is a protein complex secreted by cells in the lungs to keep the lungs from collapsing by decreasing surface tension in the alveoli

Answer 9

* Regulated by neurons (referred to as the respiratory center) located in the **medulla oblongata** * when the **_partial pressure of CO2 in the blood rises,_** the medulla oblongata stimulates and increase in the rate of ventilation

Answer 10

by **_peripheral chemoreceptors_**, which indirectly stimulate the respiratory center changes in acid-base chemistry due to kidney function can also influence ventilation

Answer 11

* Dense network of minute blood vessels called pulmonary capillaries surround the alveoli * Gas exchange occurs by diffusion across the capillary walls and those of the alveoli * gas moves from the higher partial pressure to the lower partial pressure

Answer 12

* **_Total lung capacity_** - maximum volume of air the lungs can hold * **_Tidal volume_** = volume of air moved during a normal resting breath , significantly less than lung capacity * **_Inspiratory reserve volume_** = Volume of air that could be additionally inhaled into the lungs at the end of a normal, resting inhalation * **_Expiratory reserve volume_** = the volume of air left in the lungs at the end of a normal, resting exhalation * **_Vital capacity_** = volume of air moved during a maximum inhalation followed by a maximum exhalation * **_Residual volume_** = even after maximum exhalation, there is always some air left in the lungs

Answer 13

* Collect excess interstitial fluid and return it to the circulatory system, maintaining the balance of body fluid * absorb chylomicrons from the small intestine and deliver them to cardiovascular circulation

Answer 14

* Heterotrophic = unable to synthesize all of their own nutrients * humans

Answer 15

1. **_Ingested (eaten)_** 2. **_Digested (breakdown)_** * consists of the degredation of large molecules into smaller molecules that can be absorbed into the bloodstream and used directly by cells * **Intracellular digestion:** occurs within the cell, usually in membrane bound vesicles * **Extracellular digestion:** digestive process that occurs outside the cell, within a lumen or tract

Answer 16

1. Oral cavity 2. pharynx 3. esophagus 4. stomach 5. small intestine 6. large intestine 7. anus * Accessory organs, such as the salivary glands, pancreas, liver and gallbladder, also play essential roles in digestion

Answer 17

* mechanical and chemical digestion of food begins * **_Mechanical_** - breakdown of large food particles into smaller particles through physical actions = **mastication** or churning motion * **_Chemical_** - **enzymatic breakdown** of macromolecules into smaller molecules when the salivary glands secrete saliva * **salive lubricates** food to facilitate swallowing and provides a solvent for food particles * Salive contains enzymes **salivary amylase (ptyalin),** which hydrolyzes starch to maltose (disaccharide) * **_Creates a bolus_**

Answer 18

enzyme that hydrolyzes starch to maltose (disaccharide)

Answer 19

* Muscular tube leading from the mounth to the stomach * Food is moved down esophagus by **_peristalsis_** * The esophagus is closed off from the stomach by contraction of muscular structure called the **_lower esophageal (cardiac) sphincter_** * Body of esophagus lies within the thoracic cavity, negatively pressured relative to the environment on inhalation * **abdominal cavity = positive pressure** * Therefore without normal defense mechanisms, leads to stomach acid in esophagus = aka, **_gastroesophageal reflux disease (GERD)_**

Answer 20

* Reflux can occur after spontaneous transient lower esophageal sphincter relaxation not associated with swallowing * Patients with GERD usually have a decreased lower esophageal sphincter pressure (5-10 mmHg above gatric baseline pressure), leading to an increased passage of stomach contents into esophagus * Resting pressures of the lower esophageal sphincter normally range from 15-35 mmHg above gastric baseline pressure

Answer 21

* Walls are lined by a gastric mucosa, contains gastric glands * Mucous cells in gastric pits along the membrane secrete mucus to protect the stomach lining from the harsh acidic juices (pH = 2) in the stomach * **_Chief cells_** found within the gastric glands **synthesize pepsinogen**, converted to **pepsin** upon contact with stomach acid and **breaks down proteins** * **_Parietal cells,_** also present within gastric glands, **synthesize and release HCL**, which alters the pH of the stomach and kills bacteria and intrinsic factor, necessary for **absorption of vitamin B₁₂** * Churning of stomach (mechanical, combinded with enzyme activity (chemical) produces acidic, semifluid mixture of partially digested food = **_chyme_** * passed to duodenum throug the **_pyloric sphincter_**

Answer 22

* Chemical digestion is completed in the small intestine * Divided into three section: * **_Duodenum_** * **_Jejunum_** * **_ilieum_** * Highly adapted to absorption * to max the SA, for digestion and absorption, the intestin is extremely long and highly coiled. * Also **contains projections called _vili_** * contain **capillaries and lacteals** (vessels of the lyphatic system) * A**mino acids and monosaccharides** pass through the villi walls into the **capillary system** * **Blood from digestive tract enters** portion of **liver** where it is **detoxified** and stripped of some of its nutrients * **Large fatty acids and glycerol** pass into **lacteals** and are then reconverted into **triglycerides in the liver** * Note glucose and Amino Acids are actively absorbed, require energy

Answer 23

* Into the liver * Amino Acids and monosaccharides pass through the villi walls into capillary system (active transport) * Large fatty acids and glycerol pass into the lacteals (lymphatic system vessels) and reconverted to triglyceride

Answer 24

* **Duodenum,** where the secretions of the intestinal glands, pancrease, liver and gallbladder mix together with the acidic chyme entering from the stomach

Answer 25

* **_Lipases_** - fat digestion * **_aminopeptidase_** - polypeptide digestion * **_disaccharideases_** - for maltose, lactose and sucrose digestion (eg. lactase)

Answer 26

* **_Gastin:_** * Primary function = **stimulate histamine and pepsinogen secretion as well as increase gastric blood flow** * Also stimulates parietal cells to produce HCL, which denatures proteins and activates digestive enzymes * Produced in the **G cells of the duodenum**

Answer 27

Intrinsic factor: * **Secretion of the parietal cells** * Function = facilitate the **absorption of vitabmin B₁₂** across the intestinal lining

Answer 28

Cholecystokinin (CCK): * Produced and stored in the **I cells of the duodenal and jejunal mucosa** * Function = stimulation of **pancreatic enzymes and somatosatin secretion as well as gallbladder contraction** * acts as a **hunger suppressant**

Answer 29

**_Secretin:_** * Synthesized and stored in the **S cells of the upper intestine** * Function = **stimulates the secretion of bicarbonate-containing substances from the pancrease and inhibits gastric emptying and gastric acid production**

Answer 30

* **_Produces bile_** that is **stored in the gallbladder** before being **released into the small intestine** * **bile** contains **no enzymes**; it **emulsifies fats,** breaks down large globules into small droplets * Emulsification of fat exposes a **greater surface area** of the fat to the action of **pancreatic lipase** * **_Additional functions_** = storage of glycogen, converstion of ammonia to urea, protein synthesis, detoxification and cholesterol metabolism

Answer 31

fats cannot be digested

Answer 32

* **_Produces enzymes_** such as: * **amylase = carbohydrate digestion** * **trypsin = protein digestion** * **lipase = fat digestion** * When the pancrease releases chymotrypsin and enterokinase, **enterokinase cleaves trypsinogen into trypsin** * Trypsin then cleaves and **activates the other zymogens** (enzyme precursors) * Pancrease **secretes a bicarbonate-rich juice that neutralizes acidic chyme from stomach** * Pancrease opperates optimally at this **higher pH**

Answer 33

approximately 1.5 m long and **_absorbs salts and any water not already absorbed_** by the small intesting **_Rectum_** provides for transient storage of feces before elimination through the anus

Answer 34

**Deamination** of amino acids in the **liver** leads to the production of **nitrogenous wastes**, such as urea and ammonia

Answer 35

* **_lungs_** * **CO₂ and H₂O vapor diffuse** from the blood and are continually exhaled * **_liver_** * processes **nitrogenous wastes, hemoglobin and other chemicals for excretion** * **Urea is produced** by the deamination of amino acids **in the liver** and diffuses into the blood for ultimate **excretion in the kidnesy** * **_skin_** * excrete **H₂O and dissolved salts (urea)** * perspiration serves to **regulate body temperature** since the evaporation of sweat removes heat from the body * **_kidnesy_** * functions to **maintain the osmolarity of the blood,** excrete numerous waste products and toxic chemicals and conserve glucose, salt and water * Bile salts are excreted as bile and pass out with the feces

Answer 36

* **_Function =_** **regulate the concentration of salt and water in the blood** through the formation and excretion of urine * **_Location/description_** = bean-shaped and located **behind the stomach and liver** * each kidney is composed of approximately one million units called **nephrons**

Answer 37

* Kidney is divided into three regions: * **outer cortex** * **Inner medulla** * **renal pelvis** * **Nephron** consists of: * **bulb = _bowman's capsule_** = embraces a special **capillary bed** called a **_glomerulus_** * Bowman's capsule leads to a long, coiled tube divided into funcionally distinct units: * **_proximal convoluted tubule (cortex)_** * **_Loop of Henle (medulla)_** * **_distal convoluted tubule (cortex)_** * **_collecting duct (medulla)_** * Most of nephron is surrounded by a **complex peritubular capillary network** that facilitates **reabsorption of amino acids, glucose, salt and water**

Answer 38

1. **_Filtration:_** * **Blood pressure forces 20%** of blood plasma **to glomerulus** through capillary walls into Bowman's capsule * Fluid and small solutes entering = **filtrate** (isotonic with blood plasma) * Passive process **driven by hydrostatic pressure of blood** * high BP = high hydrostatic P and can lead to kidney damage overtime 2. **_Secretion:_** * nephron **secretes waste substances** such as **acids, ions and other metabolites** from the interstitial fluid into the filtrate by **passive and active transport** 3. **_Reabsorption:_** * Essential substances **(glucose, salts and amino acids) and water** are reabsorbed from the filtrate and returned to the blood * primarily occurs in **proximal convoluted tubule** and is an active process (water passive process) * forms concentrated urine, **hypertonic to the blood**

Answer 39

blood cells and albumin which remain in the circulatory system

Answer 40

clean the blood plasma of unwanted substances as the filtrate passes through the kidney

Answer 41

proximal convoluted tubule

Answer 42

regulation of water, sodium and potassium concntrations in the nephron

Answer 43

major site for secretion of substances into the filtrate

Answer 44

* Each part plays a distinct role in regulating water absorption and electrolyte concentration * **_Descending =_** very **permeable to water**, but not to ions or urea * **_Ascending =_** * **_thin_** = impermeable to water but **permeable to ions,** allowing for passive diffusion of ions * **_thick_** = **sodium, potassium and chloride are actively reabsorbed from the urine**

Answer 45

* **Osmolarity gradient between the tubules and the interstitial fluid** surrounding them * By e**xiting and re-entering at different segments of the nephron, solutes such as Na+ and Cl-, create this osmolarity gradient**, with _tissue osmolarity increasing from the cortex to the inner medulla_ * gradient depends on the **_counter-current-multiplier system_** * system in which **energy is used to create a concentration gradient**

Answer 46

* Causes the **interstitial space in the medulla to be _hyperosmolar_ with respenct to the dilute filtrate in the renal tube** * filtrate travels down the collecting ducts to pelvis and ureter * water flows from the ducts to the interstitial fluid through osmosis * **The reabsorption zone of H2O in the kidneys depends on the permeability of the collecting ducts to water** * **regulation of the permeability of the ocllecting ducts to water is accomploished by** **_antidiuretic hormone (ADH) = vasopressin_** * ADH increases =increase permeability of collecting ducts to H2O, * more water to be absorbed and higher urine concentration *

Answer 47

* **_Aldosterone:_** * causes increased transport of sodium and potassium ions along the distal convoluted tubule and collecting duct * results **= decreased excretion of Na+ and increased excretion of K+ in urine** * **additional water reabsorption** * **_Antidiuretic hormone (ADH):_** * same effect, **increased water reabsorption** * ADH directly affects water absorption by the distal convoluted tubules and collecting ducts, **opening additional aquaporins (water channels) allowing water to reabsorbed more readily** **_Both Aldosterone and ADH cause a decrease in urine output and increase in blood pressure_**, allowing human body to compensate for periods of dehydration or other causes of low blood pressure

Answer 48

drugs that target different parts of the kidneys to cause an increase in urine production increaseing the amount of water preent in the urine and therefore increasing urine secretion

Answer 49

* pH remains relatively constant at 7.4 * **removal of CO2 by the lungs and hydrogen ions by kidneys**

Answer 50

* arterial pH * arterial partial pressure of carbon dioxide (P_co2) * plasma bicarbonate (HCO₃^-)

Answer 51

1. **_Respritory_**: affects the blood acidity by causing changes in the P_co2 * Compensation performed by respiratory system 2. **_Metabolic:_** affects the blood acidity by causing changes in the HCO₃^- * Compensation performed by kidneys * therefore take long time

Answer 52

reabsorption

Answer 53

proximal tubule

Answer 54

hypertonic

Answer 55

* **_Endocrine glands_** = synthesize and secrete chemical substances called hormones directly into the circulatory system * **_Exocrine glands_** = such as the gallbladder, secrete substances trensported by ducts

Answer 56

1. pituitary 2. hypothalamus 3. thyroid 4. parathyroid 5. adrenal 6. pancrease 7. testes 8. ovaries 9. pineal gland 10. kidneys 11. gastrointestinal glands 12. heart 13. thymus

Answer 57

* Location: on top of the kidneys * Consist of: * Adrenal cortex * Adrenal medulla

Answer 58

* In response to stress, **_adrenocorticotropic hormone (ACTH), produced in the anterior pituitary,_** **stimulates the adrenal cortex to produce** more than two dozen different steroid hormones, collectively known as **adrenocortical steroids (or corticosteroids**): * There are three major classes of corticosteroids: * Glucocorticoids * Mineralocorticoids * Cortical sex hormones

Answer 59

bound to transport proteins called **_transcortins_**

Answer 60

Adrenal cortex * such as **_cortisol**_ and _**cortisone_**, involved in glucose regulation and protein metabolism * _**raise blood glucose levels by** **promoting protein breakdown and gluconeogenesis**_ * **__**decreasing protein synthesis * **_glucocorticoids are antagonistic to the effects of insulin_** * **release amino acids** from skeletal muscles **as well as lipids** from adipose tissue * permote the peripheral **use of lipids** and have **anti-inflammatory effects**

Answer 61

Adrenal Cortex * **Aldosterone,** regulate plasma levels of sodium and potassium and the total extracellular fluid volume * Aldosterone causes **active reabsorption of sodium and passive reabsoprtion of water in the nephron of kidney** * ***increase in blood volume and blood pressure*** * Excess aldosterone = excess retention of water, hypertension (high blood pressure) * Mineralocorticoids are stimulated by **angiotension II and inhibited by ANP** (atrial natriuretic peptide)

Answer 62

Adrenal Cortex * In both men and women, AC secretes small quantities of **_androgens (male sex hormones)_** like **androstenedione and dehydroepiandrosterone** * In **men**, most androgens are **produced by testes**, so the physiologic effect of the andrenal androgens is quite small * **Women**, however, overproduction of adrenal androgens may **cause excess facial hair,** etc.

Answer 63

* **"Fight or flight"** * Two hormones: * **_Epinephrine (adrenaline)_** * Increases the conversion of glycogen to glucose in liver and muscle tissue, increase in blood glucose and basal metabolic rate * **_Norepinephrine (noradrenaline)_** * Both: * **increase rate and strength** of the heartbeat and dilate and constrict blood vessels, * **increase blood supply** to skeletal muscles, heart and brain * **decrease blood supply** to kidneys, skin and digestive tract * promote **release of lipids** by adipose tissue * also **neurotransmitters** * Both of which belong to the class of amino acid-derived compounds called **_catecholamines_**

Answer 64

* The pituitary (**_Hypophysis_**) is a small, trilobed gland at the base of the brain * **two main lobes:** * **_Anterior_** * **_Posterior_** * Hangs below the hypothaamus and is connected to it by a slender cord = **_infundibulum_**

Answer 65

* **Synthesizes** both: * **_direct hormones_** - directly act on target organs * **_tropic hormones_** - stimulate other endocrine glands to release hormones * Hormonal secretion of the anterior pituitary are **_regulated by hypothalamic hormones_** = **releasing/inhibiting hormones or factors**

Answer 66

**_Direct hormones - direct effect_** * **_Growth hormones (GH, somatotropin):_** * Promotes **bone and muslce growth** * promotes **protein synthesis and lipid mobilization and catabolism** * deficiency - dwarfism, over production = gigantism * adults over production = **acromegaly** * **_Prolactin:_** * stimulates **milk production** in female mammary glands

Answer 67

**_tropic = stimulate other endocrine glands_** * **_Adrenocorticotropic hormone (ACTH):_** * **stimulates adrenal cortex to synthesize and secrete glucocorticorids and regulate corticotropin-releasing factors (CRF)** * **_Thyroid-stimulating hormone (TSH):_** * **stimulates thyroid gland to** **synthesize and release thyroid hormone**, including **thyroxin** * **_Lutenizing hormone (LH):_** * **Women:** stimulates ovulation and maintenance of **corpus luteum** and regulates **progesterone secretion** * **Men:** stimulates interstitial cells of testes to **synthesize testosterone** * **_Follicle-stimulating hormone (FSH):_** * **Women:** maturation of ovarian follicles, turn **secrete estrogen** * **Men:** maturation of the seminiferous tubules and **sperm production** * **_Melanocyte-stimulating hormone (MSH):_** * secreted by intermediate lobe of pituitary. Mammals function unclear, **darkening of skin** pigment melanophore cell dispersion * **_Endorphins:_** * neurotransmitters that help **pain-relieving** properties

Answer 68

* The posterior pituitary **_(neurohypophysis)_** **does not synthesize hormones; it stores and releases the peptide hormones:** * **_Oxytocin:_** * secreted during childbirth, **increases** the strenth and frequency of **uterine muscle contractions** * stimulates milk secretion in mammary glands * **_Antidiuretic hormone (ADH, vasopressin):_** * **increases the permeability of the nephron's collecting duct to water** * promoting water reabsorption, increase blood volume, increases blood pressure * Secreted when plasma osmolarity increases, sensed by **osmoreceptors in hypothalamus,** * or when blood volumes decreased, sensed by **baroreceptors in the circulatory system** * Which are both **produced by the neurosecretory _cells of the hypothalamus_** * hormone secretion is stimulated by action potentials descending from the hypothalamus

Answer 69

* part of **forebrain** and located **directly above the pituitary gland** * receives neural transmission from ther parts of the brain and from peripheral nerves, **triggering response from neurosecretory cells** * these cells **regulate pituitary gland secretion** via negative feedback and **inhibiting/releasing hormones**

Answer 70

stimulates the anterior pituitary to secrete FSH and LH

Answer 71

1. hypothalamic cells (via a negative feedback mechanism) release corticotropin-releasing factor (CRF) into the portal system, which signals the pituitary cells to release ACTH 2. ACTH then acts on the adrenal cortex to increase glucocorticoid levels 3. when the plasma concentration of corticosteroids exceeds the normal plasma level the steroids themselves exert an inhibitory effect on the hypothalamus

Answer 72

Neurosecretory cells in the hypothalamus synthesize both oxytocin and ADH and transport them via their axons into the posterior pituitary for starage and secretion

Answer 73

* Thyroid hormones affect the function of nearly every organ system in the body * _**children**,_ these hormones are essential for **growth and neurological development** * **_adults_**, hormones increase the rate of **metabolism** throughout the body and maintenance of **metabolic stability**

Answer 74

* **_Thyroxine (T4)_** * **_Triiodothyronine (T3)_** * **_Calcitonin:_** **"tones the bone"** * **antagonist to parathyroid hormone (PTH)** * T4 and T3 formed from glycoprotein thyroglobulin, synthesized in thyroid cells

Answer 75

* T3 is 5 times more potent than T4 * T4 and T3 are transported via plasma proteins * All of the T4 in the body is formed and secreted by the thyroid gland; however, 20% of T3 is produced by the thyroid gland * The majority of T3 is produced by conversion of T4 to T3 by the enzyme 5'-monodeiodase, found primarily in the peripheral tissues

Answer 76

* **_Hypothyroidism_** = thyroid hormones are **undersecreted** or not secreted at all * **Symptoms** = slowed heart rate, respiratory rate slowed, fatigue, cold intolerance, weight gain * **Infants = cretinism** - mental retardation and short stature * **Hyperthyroidism** = thyroid is **overstimulated,** over secretion of thyroid hormones * **Symptoms** = increased metabolic rate, feels of excessive warmth, profuse sweating, palpitations, weight loss, and protruding eyes Both normally due to a **thyroid enlarged**, formoing a bulge in the neck called a **_goiter_**

Answer 77

* The pancrease is **both an exocrine organ and an endocrine organ** * **_exocrine function_** = performed by the cells that secrete **digestive enzymes into the small intestine** via series of ducts * **_endocrine function_** = performed by small glandular structures called the **islets of Langerhans, alpha and beta cells** * **_alpha cells = glucagon_** * **_beta cells = insuline_**

Answer 78

* **_Glucagon_** * **stimulates protein and fat degradation,** conversion of glycagen to glucose, and gluconeogenesis = **_increase blood glucose_** * **antagonist to insulin** * **_Insulin_** * stimulates **uptake of glucose by muscles and adipose cells** and storage of **glucose as glycagen in muscles and liver cells** = **_lowering blood glucose_** * Stimulates **synthesis of fats** from glucose and **uptake of amino acids** * **antagonistic to glucagon and glucocorticoids**

Answer 79

underproduction of insulin, or insensitivity to insulin = hyperglycemia (high blood glucose levels)

Answer 80

see attached

Answer 81

* Four small, pea-shaped structures embedded in the posterior surface of the thyroid * Synthesize and secrete **_parathyroid hormone (PTH)_**, which regulates plasma Ca2+ concentration * PTH **_raises the Ca2+ concentration in the blood_** by **breaking down bon**e and d**ecreasing Ca2+ excretion in the kidneys** * Calcium is bound to phosphate in bone, PTH compensates for the increase in phosphate by stimulating excretion of phosphate by the kidneys

Answer 82

* When **blood volume falls**, the kidneys produce **_renin_** * enzyme that converts plasma protein angiotensinogen to angiotensin I * **Angiotensin I is converted to angiotensin II**, stimulates the adrenal cortex to **secrete aldosterone** * Aldosterone = helps **restore blood volumes by increasing sodium reabsorption by kidneys** = increased fluid retention * Kidneys also produce **_erythropoietin (EPO)_** * glycoprotin that **stimulates red blood cell production**

Answer 83

stimulates red blood cell production, produced in the Kidneys * Stimulation of the stem cells to differentiate into rubriblasts (least mature erythrocytes) * Increased rate of mitosis * Increased release of reticulocytes from the bone marrow * Increased hemoglobin (HgB) formation, which results in the critical HgB concentration necessary for RBC maturity to be reached at a more rapid rate

Answer 84

* Ingestion of food stimulates the **stomach** to release the hormone **_gastrin_** * carried to the **gastric glands** and stimulates the glands to **serete HCL** * The hormone **_secretin_** is released by the **small intestine** when acidic chyme enters from the stomach * stimulates the **secretion of an alkaline bicarbonate solution** from the pancrease that neutralizes the acidity of the chyme * The hormone **_cholecystokinin_** is released by the **small intestine** in response to the presence of fats and **causes the contraction of the gallbladder and release of bile** into the small intestine * bile, not a hormone, involved in emulsification and **digestion of fat**

Answer 85

* Pineal gland is a tiny structure at the base of the brain * **_secretes melatonin_** * circadian rhythms

Answer 86

* range from simple **short peptides** (amino acid chains), such as **ADH, to complex polypeptides, such as insulin** * **Peptide hormones = first messanger,** bind to **receptors**, **trigger a series** of enzymatic reactions * converstion of **ATP to** cyclic adenosine monophosphate (**Cyclin AMP**) * **Cyclic AMP acts as secondary messenger** * relays message from extracellular peptide to cytoplasmic enzymes * **Cascade effect** with each stop, amplifying effect

Answer 87

* such as **estrogen and aldosterone** = **lipid derived molecules** with ring structure * **Cross the phospholipid bilayer** and enter their target cells **directly** with a receptor molecule * receptor-hormone complex enters the nucleus and directly activates the expression of specific genes by binding to receptors on the chromatin

Answer 88

* The production of functional sex cells or gametes by adult organisms * The union of these cells (fertilization or conjugation) to form a zygote * The development of the zygote into another adult, completing the cycle

Answer 89

* Gametes produced in specialized organs called **_gonads_** * **_Male gonads_** = testes, produce **sperm** in the tightly **coiled seminiferous tubules** * **_Female gonads_** = ovaries, produce **oocytes (eggs)**

Answer 90

possess **both functional male and female gonads** these include the **hydra** and the **earthworm**

Answer 91

* Gametogensis = production of functional sex cells * **_Males = spermatogenesis_** * **sperm production**, and occurs in the seminiferous tubules of the testes * **_Females = oogenesis_** * **egg production**, and occurs in the ovaries

Answer 92

* **_Testes are located in the scrotum_** - external pouch that maintains the testes' temperature at 2degC to 4degC lower than body temperature, a condition essential for sperm survival * Sperm path from the testes: * **from testes, through the vas deferens to the ejaculatory duct, then to the urethra** * The urethra passes through the penis until it terminates with an external opening at the glans of the penis

Answer 93

***_Spermatogenia -\> primary -\> secondary -\> spermatid -\> spermatazoa_*** * **_Spermatogenesis, or sperm production_** * occurs in the **seminiferous tubules** * Diploid cells called **_spermatogenia_** differentiate into diploid cells called _**primary spermatocytes**,_ which undergo a meiotic division to yield _two haploid_ **_secondary spermatocytes_** of equal size; a second meiotic division produces _four haploid **spermatids**_ of equal size * After meiosis the spermatids undergo a final series of changes that increase their mobility, resulting in **mature sperm**, or **_spermatozoa_**

Answer 94

elongated cell with a head, neck, body and tail * **_Head_** - **nucleus** * **_tail (flagellum)_** **propels** the sperm, while mitochondria in the neck and body provide energy for locomotion * A **caplike structure** called the **_acrosome,_** derived from the golgi apparatus, develops over the anterior half of the head * contains enzymes needed to **penetrate the though outer covering of the ovum**

Answer 95

* **_Ovaries_** consist of thousands of follicles * **_Follicle_** = multilayered sac of cells that contain, nourishes, and protects an immature ovum * Follicle cells **produce estrogen** * **_Once a month_** an immature **follicle is released** and travels via cilia **into the _oviduct (fallopian tube)_** * fallopian tube opens into the **_uterus,_** site of **fetal development** * Lower narrow end of the uterus= **_cervix_** that connects to the vaginal canal * vaginal canal is the site of sperm deposition during intercourse

Answer 96

Primary oocytes -\> after menarche -\> secondary oocytes -\> Mature with two layers * **_Oogenesis_ = production of female gametes** * **occurs in the ovarian follicles** * At birth, most of the immature ova (primary oocytes) that the female will produce is already formed * **_Primary oocytes = diploid_** * formed by **mitosis in the ovary** * After **_menarche_** **(first female menstration**), **one primary oocyte** per month completes **meiosis I**, yeilding two daughter cells of unequal size = **_secondary oocyte_** **and** a small cell = **_polar body_** * secondary oocyte is **expelled** from follicle **during ovulation** * **Meiosis II does not occur until fertilization** * The oocyte cell is surrounded by **two layers** * **_inner zona pellucida layer_** * **_outer corona radiata layer_** * **Meiosis II is triggered** when these **layers are penetrated** by a sperm, yielding two haploid (**mature ovum and polar body)**

Answer 97

* The secretion of both estrogens and progestersons in the ovaries is regulated by **luteinizing hormone (LH) and follicle stimulating hormone (FSH), which are _regulated by honadotropin-releasing hormone (GnRH)_** * **_Estrongen:_** secreted by **ovarian follicles and corpus luteum** * Steroid hormones for **normal female maturation** * Stimulate development of female reproductive tract, contriute to development of secondary sexual characteristics, and influence libido * Responsible for **thickening of the endometrium** (inner lining of the uterine walls) * **_Progesterone:_** secreted by the **corpus luteum** * steroid hormone secreted **during the luteal phase of the menstrual cycle** * Stimulates the **development and maintenance of the endometrium in preparation for implantation**

Answer 98

ovaries, hypothalamus and anterior pituitary

Answer 99

1. **_Folliclar phase_** * **Begins when menstrual flow from previous cycle stops** * During phase, **FSH** from anterior pituitary **promotes development of follicle**, which grows and begins **secreting estrogen** 2. **_Ovulation_** * **Midway** through cycle a mature ovarian **follicle bursts and releases an ovum** * **Surge in LH due to peak in estrogen level** 3. **_Luteal phase_** * **LH maintains the remnant of the ruptured follicle, called the *corpus luteum***, which **secretes estrogen and progesterone** * **Progesterone causes** the glands of the **endometrium to mature,** **prepare for embryo implantation** * Progesterone and estrogen are essential for maintenance of endometrium 4. **_Menstration_** * If **ovum is not fertilized**, the **corpus luteum atrophies** * Resulting in a **drop of progesterone and estrogen** levels causing **endometrium to slough off = menstrual flow (*menses*)** * If **ovum is fertilized**, the developing **placenta produces *hCG (human chorionic gonadotropin),* maintaining the corpus luteum** and supply of **estrogen and progesterone** * eventually placenta will take over production of these hormones

Answer 100

* An egg can be fertilized during the 12-24 hours after ovulation * occurs in the lateral, widest portion of the fallopian tube * sperm travels through the vaginal canal, cervix, uterus, and into fallopian tubes to reach the ovum * Sperm remains viable for fertilization for 1-2 days after intercourse

Answer 101

* **Layers:** * Sperm must **first penetrate _corona radiata_** * **enzymes** secreted by sperm aid in penetration of this layer * Sperm **then penetrate the _zona pellucida_**_,_ **using *_acrosome,_*** * releases **enzymes that** **digest this layer** * Once in contact with ovum cell membrane, s**perm forms a *tube like structure* called the *_acrosomal process_*, fusing sperm cell membrane with ovum** * sperm nucleus now enters the ovum's cytoplasm and ***completes meiosis II*** * **Acrosomal reaction triggers a *_cortical reaction_* in the ovum** * causes ***calcium ions to release*** into cytoplasm = **formation of the *_fertilization membrane_*** * membrane - **hard layer prevents multiple fertilizations** * **Calcium** also **stimulates metabolic changes** in ovum, ***increasing metabolic rate*** = first **mitotic division of the zygote soon follows**

Answer 102

* Result when a **_single zygote splits into two embryos_** * of splitting occurs at the **_two-cell stage_** of development, embryos will **separate chorions and separate placentas** * If occurs at **_blastula stage_**, embryos will have **one chorionic sac and share placenta and possibly an amnion** * Same zygote = Same sex, blood type and so on

Answer 103

* **Two ova are released in one ovarian cycle** and fertilized by **_two different sperm_** * two embryos implant into uterine wall individually * Each with own placenta, amnion, and chorion * **_Two distinct zygotes_**

Answer 104

abdominal cavity which then the cilia in the fallopian tube direct it into there

Answer 105

prostate, bulbourethral (Cowper's) gland, seminal vesicles

Answer 106

suprarenal glands

Answer 107

* Characterized by a series of rapid mitotic divisions = ***_cleavage_*** * lead to an increase in cell number without a corresponding growth in cell protoplasm (total volume of cytoplasm remains constant) * Therefore, cleavage is progressively **smaller cells with an increasing ratio of nuclei to cytoplasm** * **increase in surface to volume ratio** * ****First cleavage = 32 hours after fertilization * Second = 60 hours * Third = 72 hours * eight celled embryo reaches the uterus * **_mortula forms into blastula (series of steps)_** * mortula, blastulation after murtula forms blastocole, blastula * **blastula implants into uterus**

Answer 108

* A **solid ball** of embryonic cells, **_mortula_**, is formed * **_Blastulation_** begins when the m**ortula develops a fluid-filled cavity** called the **_blastocoel_**, which by the fourth day becomes a **hollow sphere** of cells called the **_blastula_** * **blastula implants into the uterus**

Answer 109

* After two weeks, the embryo is fully implanted in the uterus and **cell migration transform the single cell layer of blastula into a three-layerd structure** = **_gastrula_** * three germ layers * **_Extoderm_** * **_Endoderm_** * **_Mesoderm_**

Answer 110

* intergumentary system * (epidermis, hair, nails, and epithelium of nose, mouth and anal canal) * Lenses of the eye * retina * nervous system

Answer 111

* epithelial linings of the digestive and respiratory tracts (including the lungs) * Part of the liver, pancrease, thyroid and bladder lining

Answer 112

* Musculoskeletal system * circulatory system * excretory system * gonads * connective tissues throughout the body * portions of digestive and respiratory organs

Answer 113

* by the end of gastrulation, regions of the germ layers begin to develo into a rudimentary nervous system * starts before week three

Answer 114

* A **rod of mesodermal cells develop**, **_notochord,_** along the longitudinal axis of the embryo, **just under the dorsal layer of ectoderm** * Notochord has an inductive effect on the overlaying ectoderm, **causing it to bend inward** * form a groove along the dorsal surface of embryo * **Dorsal extoderm folds on either side of the groove;** these neural folds grow upward and finally fuse, **forming a closed tube** * This **_neural tube_**, gives rise to the **brain and spinal cord (central nervous system)** * once neural tube is formed, it detaches from surface of ectoderm

Answer 115

called **_neural crest cells_** * These cells migrate laterally and give rise to many components of the **peripheral nervous system** * **_Sensory ganglia_** * **_autonomic ganglia_** * **_adrenal medulla_** * **_schwann cells_**

Answer 116

**_Spina bifida_** mother takes **_folic acid supplement_s** during pregnancy

Answer 117

* **_Organogenesis:_** * Body organs begin to form * In this process, the cells interact, differentiate, change physical shape, proliferate and migrate * **_Growth:_** * Organs increase in size * continual process from infancy through childhood to adulthood * **_Gametogenesis:_** * Egg develop in wome and sperm develop in men, permits reproduction to occur

Answer 118

* Fetus receives oxygen and removes metabolic wastes and CO2 through mother in a **specialized circulatory system** * Two components: * **_Placenta_** * **_Umbilical cord_** * both develop in the first few weeks after fertilization

Answer 119

* They are **outgrowths of the four extra-embryonic membranes formed during development:** * **_amnion_** * **_chorion_** * **_allantois_** * **_yolk sac_**

Answer 120

* thin, tough membrane containing a **watery fluid called the _amniotic fluid_** * acts as a **_shock absorber_** of external pressure during gestation and localized pressure from uterin contractions during labor

Answer 121

* Where placenta formation begins * a membrane that **completely _surrounds the amnion_** * assists with **_transfer of nutrients_** from mother to fetus

Answer 122

* Third placental membrane * develops as an **outpocketing of the gut** * **Blood vessels of the allantoic wall enlarge and** **become the *_umbilical vessel_***, which will connect the fetus to the developing placenta

Answer 123

* Site of **early development of blood vessles** * **becomes associated with the umbilical vessels**

Answer 124

* First weeks: * major organs begin to develop * **heart begins beating** at 22 days * **eyes, gonads, limbs and liver start to form** * by 5th week: * 10 mm long * 6th weeks * 15 mm long * 7th week * **Cartilaginous skin begins to turn to bone** * 8 week * most of the **organs have formed, brain is fairly developed** * **_embryo = fetus_** * End of ninth week: 9 cm long

Answer 125

* Fetus does a tremendous amount of **_growing_** * Begins to move around in the amniotic fluid * **Face appears human** * **toes and fingers** elongate * end of sixth month, fetus 30-36 cm long

Answer 126

* Seventh and eighth months * **_rapid growth and further brain development_** * Ninth month, **antibodies** are transported by highly selective active transport from mother to baby * Growth rate slows and fetus becomes less active as less room to move

Answer 127

* child birth is from **_labor_** * series of strong uterine contractions * _Three stages of labor:_ 1. **_cervix thins and dialates and the amniotic sac ruptures releasing fluid_** * contractions are relatively mild 2. **_Rapid contraction period_** * resulting in the **birth** of the baby * **Umbilical cord cut** 3. Uterus contract, **_expelling the placenta and the umbilical cord_**

Answer 128

aka **_birth defects_** * Chemical and biological agents that cause disorders = **_teratogens_** * some drugs, such as alcohol and tobacco, and some microorganisms such as viruses and bacteria

Answer 129

mother passes on an **infection directly to her developing offspring** can occur either during development or birth

Answer 130

* The zygote divides mitotically to form the mass of cells called the embryo * _**Embryo** consists of the following parts:_ * **_Epicotyl_** * Precursor of the **upper stem and leaves** * **_Cotyledons_** * **Seed leaves,** dicots have two seed leaves, while monocots have only one * **_Hypocotyl_** * **lower stem and root** * **_Endosperm_** * **feeds the embryo**; in dicots, the cotyledon absorbs the endosperm * **_Seed Coat_** * develops from the **outer covering of the ovule**, the embryo and its sead coat together comprises the seed

Answer 131

* The fruit in which the seed develop is formed from the ovary walls, the base of the flower, and other consolidated flower pistil components * serves as a means of seed dispersal

Answer 132

growth in higher plants is restricted to the **embryonic (undifferentiated) cells** called **_meristem_** cells Gradually, the cells elongate and **differentiate into cell types characteristic of the species**

Answer 133

* Meristem cells = embryonic (undifferentiated) cells 1. **_Apical meristem_** * found in the **tips of roots and stems** * **growth** in length occurs **only at these points** 2. **_Lateral meristem (Or cambium)_** * Located between the **xylem and phloem** * Permits **growth in diameter** and can differentiate into new xylem and phloem cells * It is **not an active tissue in monocots (grasses) or herbaceous dicots (alfalfa)** but is predominant in ***_woody dicots like oak_***

Answer 134

automatic responses to simple stimuli and are recognized as reliable behavioral responses following a given environmental stimuli

Answer 135

controlled at the spinal cord, connecting a two-neuron pathway from the receptor (afferent neuron) to the motor (efferent neuron) * Efferent innervates the effector (muscle or gland)

Answer 136

* like a startle response in a complex reflex, it involved the integration of many neurons in a system * responsible for sleep-wake and behavioral motivation

Answer 137

**_Habituation_** suppression of the normal start response to stimuli

Answer 138

Spontaneous recovery

Answer 139

Classical or **_Pavlovian_** conditioning also called conditioned reflex

Answer 140

Conditioned dog to salivate with an arbitrary stimulus (bell) was rung

Answer 141

Phenomenon that can be **confused with true classical conditioning** Determine if the conditioning process is actually necessary for the production of a response by a previously "neutral" stimulus **In many cases, the "neutral" stimulus is able to elicit response before conditioning, thus not really requiring conditioning** Key to examine natural stimulus prior to conditioning

Answer 142

Involves conditioning responses to stimuli with the use of **_reward or reinforcement_** have used those recently to the conditioning of visceral responses, such as changes in heartbeat

Answer 143

**_Operant conditioning and reinforcement_** * Well-known experiment - **"skinner box"**, consists of a cage with a lever or key and a food dispenser * food pellet delivered whenever the animal pressed the lever = operant response * Later experiments he varied the type of reinforcement into two categories: * **_Positive reinforcement_** * Reward = food, light or electrical stimulation of animal brain "pleasure center" * Animal was more likely to repeate the desired behavior response * developed a **positive connection between action and reward** * **_Negative reinforcement_** * links the lack of a certain behavior with a reward * Animals developed a **negative connection betwen action and reward**

Answer 144

reward when something was done ie. food delivered when animal presses the lever

Answer 145

* Punishment: * conditioning so an organism will stop exhibiting a given behavior pattern * painfully shocking organism * after, organism is less likely to repeat behavior * developes a **negative connection between stimulus and response**

Answer 146

A stimulus is usually associated with several possible responses, each response having a different probability of occurance, stimulus-behavioral association = **habit family hierarchy** * ex. A chicken may respond to light in different ways, but one way is rewarded, the rewarded response will occur with a higher probability in the future * **_reward strengthens a specific behavioral response and raises its order in the hierarchy_**

Answer 147

when the reward or reinforcement is gone

Answer 148

* **_Stimulus generalization:_** * ability of a conditioned organism to respond to stimuli that are similar, but not identical, to the original conditioned stimulus * **_Stimulus discriminiation:_** * ability of the learning organism to respond differentlly to slighly different stimuli

Answer 149

**_Imprinting_** ex. swan in a pond with hatched ducklings separated from mother and found that they eventually follow the swan like a mother

Answer 150

occurs as a means of communication between members of a species

Answer 151

* May be defined as an **_innate behavior that has evolved as a signal for communication between members of a species_** * ex. song, call, or intertional change in an animal's physical characteristics is considered a display * Categories of displays: * **_Reproductive displays:_** * function as signals in preparation of mating * **_Agonistic displays:_** * specific actions to communicate * ex like a dog display of appeasement when it wags it tail * **_Other:_** * various dancing procedures by honeybees - location and quality of food * auditory, visual, chemical and tactile elements as means of communication

Answer 152

* When food, mates or territory are disputed, a dominant member of the species will prevail over a subordinant one * **_Social hierarchy = pecking order_**

Answer 153

* Members of most land-dwelling species defend a limited area or territory from intrusion by other members of the species

Answer 154

* Olfactory sense is immensely important as a means of communication in many animals * **_pheromones_** * influence the behavior of other members of the sampe species * Pheromones can be classified into two types: * **_Releaser pheromones_** * trigger a **reversible behavioral change** in the recipient in **short-term** * **sexual attractant** pheromones * **alarm or toxic defensive** * **_Primer pheromones_** * **long-term** **behavioral and physiological alterations** in receiving animals * may effect cycles * limit sexual reproduction * Important in **social insects** like ants, bees, and termites where they regulate role determination and reproductive capacities

Answer 155

The study of interactions between organisms and their environment

Answer 156

* **_abiotic_ = physical or nonliving environtment** * climate, temperature, availability of light and water, and the local topology * **_biotic_ = living environment** * all living things that directly or indirectly influence the life of the organism * including the relationships that exist between organisms

Answer 157

organ system organ tissues cells molecules atoms subatomic particles

Answer 158

a group of organisms of the same species living together in the same location ex. lions in grassland, dandelions on a lawn, flies in a barn

Answer 159

consists of a population of different plants and animal species interacting with each other in a given environment

Answer 160

an ecological community encompasses the interaction between living biotic communities and the nonliving environment

Answer 161

monera protists plants fungi animals

Answer 162

includes **all protions of the planet that support life**: **_atmosphere_** **_lithosphere (rocks and soil surface)_** **_hydrosphere (ocean)_**

Answer 163

top layer of the water through which light can penetrate, is where aquatic photosynthetic activity takes place

Answer 164

only animal life and other heterotrophic life exists

Answer 165

* live predominantly or entirely on land * oxygen approximately 20%

Answer 166

soil and rock

Answer 167

* substratum (soil and rocks): determines the nature of plant and animal life in the soil: * Soil is affected by a number of factors: * **_Soil acidity, pH_** * Rhododendrones and pins = acidic * acid rain may make soid pH too low for most plants growth * **_Texture_** * its clay content determines how much water-holding capacity * Willows require moist soil * Most plants grow will in **loams**, high percentages of each type of soil * **_Minerals_** * including **nitrates** and **phosphates** affect type of vegitation that can be supported * Beach sand has no minerals, no plant growth * **_Humus quantitiy_** * determined by the amount of **decaying plants and animal life** in the soil

Answer 168

functional role of an organism in its ecosystem * Describes what the organism eats, where and how it obtains its food, what climactic factors it can tolerate and which are optimal, the nature of its parasites and predators, where and how it reproduces, etc * Two species cannot occupy the same nitch in the same location * if same niche results: * extinction * occupy two different location and both go extinct separately * diver due to evolution

Answer 169

organisms that manufacture their own food * Examples: * green plants (from sun light) * chemosynthetic bacteria (oxidation of inorganic sulfure, iron, nitrogen compounds)

Answer 170

cannot synthesize their own food and must depend upon autotrophs and other heterotrophs in the ecosystem to obtain food and energy * Types: * **_Herbivores:_** * consume only plants or plant food * have symbiotic bacteria that can digest cellulos to help them breakdown and utilize cellulose * often prey * cows, horses, hoofs instead of towes * **_Carnivores:_** * animals that eat only other animals * **_Omnivores:_** * eat both plants and animals

Answer 171

* **_Symbiosis_** * obligatory relationship, cannot survive without the other * Types of symbiotic relationships: Commensalism (+/0), Mutualism (+/+), Parasitism (+/-) * **_Predation_** * free-living organisms that feed on other living organisms * Carnivors and herbivores * **_Saprophytism_** * include those protists and fungi that decomposed (digest) dead organism matter externally and absorb the nutrients * ex. mold, mushrooms, bacteria of decay, and slime molds * **_Scavenging_** * animals that consume dead animals * ex. vulture, hyena, snapping turtle

Answer 172

* **_Symbiosis_** * may or may not be beneficial to both participants * **obligatory relationship, cannot survive without the other** * Types of symbiotic relationships: * **_Commensalism (+/0)_** * **__**host neither discourages nor fosters the relationship * **_Mutualism (+/+)_** * **_Parasitism (+/-)_**

Answer 173

* animals adaptation for maintaining their internal osmolarity and conserving water

Answer 174

animals and plants that are cold-blooded

Answer 175

warm-blooded

Answer 176

1. **_Producers:_** * The **autotrophic green plants and chemosynthetic bacteria** * utilize energy from the sun and simple raw materials to **manufacture carbohydrates, proteins and lipids** * ex. wheat plant 2. **_Primary Consumers:_** * animals that consume green plants **(herbivores)** * ex. cows, grasshoppers and elephant 3. **_Secondary Consumers:_** * animals that consume **primary consumers (carnivores)** * ex. frogs, tigers, dragonflies 4. **_Tertiary Consumers:_** * animals that feed on **secondary consumers (carnivores)** 5. **_Decomposers:_** * **saprophytic organisms and organisms of decay, bacteria and fungi,** as they decompose the organic wastes and dead tissues into simpler compounds, nitrates and phosphate

Answer 177

lightning and nitrogen-fixing bacteria in the roots of legumes change nitrogen to usable, soluble nitrates

Answer 178

nitrates are absorbed by plants and are used to synthesize nucleic acids and plant proteins

Answer 179

Animals eat the plansts and synthesize specific animal proteins from the plant proteins

Answer 180

Nitrogen locked up in waste and dead tissues is released by the action of bacteria of decay, which converts the proteins into ammonia (NH3)

Answer 181

* two fates await the ammonia: * some nitrified to nitrites by chemosynthetic bacteria and then to usable nitrates by nitrifying bacteria * The rest is denitrified * ammonia is broken down to release free nitrogen, returning to beginning of cycle

Answer 182

1. Decay 2. Nitrifying 3. Denitrifying 4. Nitrogen fixation They have no use for the excretory ammonia, nitrates, nitrates and nitrogen they produce; however, they do impact other living organisms

Answer 183

* Desert biome * grassland biome * rainforest biome * Temperate deciduous forest biome * Temperate coniferous forest biome * Taiga biome * Tundra biome * Polar region

Answer 184

* **receive fewer than 10 inches of rain/year** * rain is concentrated within a few heavy cloudbursts * growth season = few days after rainfall * generally small plants and animals * plants conserve water: cactus, sagebrush and mesquite * animals live in burrows (insects and lizards) * Examples: **Sahara** in africa and **Gobi** in Asia

Answer 185

* Characterized by **low rainfall (10-30 inches/year)** * provide **no shelter** for herbivorous mammals (bison, antelope, cattle, and zebra) from predators * have long legs and hoofed * ex. **prairies** east of the Rockies, **steppes** of Ukrain and **pampas** of Argentina

Answer 186

* aka **jungles,** characterized by **torrentrial rains** * **tropical rainforests** = high temperatures * **temperature rainforests** = moderate temperature * both include climax communities with dense growth of vegetation * ex. vines and **epiphytes** (plants grwoing on other plants) * ex. monkeys, lizards, snakes, and birds * Floor is inhabited by **saprophytes**, live off dead organic matter * Tropical = central africa, central america, amazon basin and southeast asia * temperate = western north and south america and islands off eastern asian and australian coasts

Answer 187

* **cold winters, warm summers, and moderate rainfall** * beech, maple, oaks, and willow trees which shed their leaves during cold winter months * animals - deer, foxes, woodchucks, squirrels, and birds * found in **northeastern and central-eastern US** and **Central Europe**

Answer 188

* **Forests are cold, dry and inhabited mainly by trees that do not lose their leaves** * such as fir, pine and spruce trees * adapted for water conservation * needle shaped leaves * Found in **extreme northern parts of US** and **southern Canada** * ***_largest biomass_*** of any terrestrial biome * trees like **redwood** * animals like beavers, bears, sheep, squirrels and birds

Answer 189

* Receive **less rainfall than temperate forest** * long, **cold winters** and like coniferous forests, are inhabited by trees that do not lose their leaves, especially **spruce** * Soils: thin soil covered in moss and lichens * animal: moose and deer, bears, wolves, rodents and birds * Exist in **extreme northern parts of Canada and Russia**

Answer 190

* **Treeless, frozen plain found between the taiga and the northern ice sheets** * covered in snow and ice for much of the year and can be described as **_permafrost_** * lichens, mosses, polar bears, musk oxen and arctic hares are found here

Answer 191

* surround the polar ice caps and are frozen areas with no vegetation and few terrestrial animals * include penguins and polar bears * little precipitation falls therefore deserts

Answer 192

* Oceans connect to form one continuous body of water, controling earth's temperature by absorbing solar heat * Distinct zones of the marine biome: * **_Intertidal zone:_** * Region **exposed at low tides,** variations in temperature and dryness * algae, sponges, clams, snails, sea urchins, starfish and crabs * **_Neritic zone:_** * **On the continetal shelf** that contains ocean with depths up to 600 ft and extends several hundred miles from the shore * algae, crabs, crustaceans and many species of fish * **_Pelagic zone:_** * typical of the **open sea,** divided into photic and aphotic zone * **_Photic zone:_** * sunlit layer of open sea extending to depth of 250-600ft * **plankton** (photosynthetic and hterotropic organisms), **nekton** (active swimmers like fish, sharks or whales that feed on plankton and smaller fish) * Chief autotroph is the **diatom**, an alga * **_Aphotic zone:_** * region **beneath the photic zone that receives no sunlight** * **only heterotrophs** * very cold, high pressure env. * contains nekton and **benthos** (crawling and sessile organisms)

Answer 193

* **Freshwater is hypotonic, creating a diffusion gradient that results in the passage of water into the cells** * freshwater organisms have homeostatic mechanisms to maintain water balance by regular removal of excess water * contractile vacuoles of protozoa and excretory systems of fish * plants have rigid cell walls thus build up cell pressure (turgor) as water flows in * pressure stops the influs * In rivers and streams, strong, swift currents exist, and thus selection favored the survival of fish that developed s**trong muscles and plants with root-like holdfasts** * Freshwater biomes, except very large lakes, are **affected by variations in climate and water** * temperature of freshwater bodies may very considerably, freeze or dry up, and mud from those floors may be stirred up by the storms

Answer 194

1. **_Domain_** * Eukarya 2. **_kingdom_** * Animalia 3. **_phyla_** (or divisions) * Chordata 4. **_class_** * Mammalia 5. **_order_** * Primates 6. **_family_** * Hominidae 7. **_genus_** * Homo 8. **_species_** * Sapiens

Answer 195

* Lack a nucleus or any membrane-bound organelles and are single-celled organisms that reproduce asexually * **_Eubacteria_** * single celled prokaryotes with a single double-stranded ciruclar loop of DNA not enclosed by a nuclear membrane * Morphological, cocci (round), bacilli (rods), spirilla (spiral),duplexes (diplo-), clusters (staph-), chains (strepto-) * ***_Cyanobacteria_*** * types of bacteria that live primarily in fresh water but also exist in marine environments * Posses a cell wall and photosynthetic pigments * **_Archaea_** * prokaryotes, and often have cell walls and flagella, also exhibit several unique variations * cell membrane composed of glycerol-ether lipids = extreme environments

Answer 196

* primative eukaryotic organisms with membrane-bound nuclei and organelles * capability to carry out all of the life processes * Types: * **_Protozoa_** * single-celled organisms that are heterotrophic * Categories: * Rhizopods = amoebas, pseudopods * ciliophors = cilia use for feeding and locomotion * **_Algae_** * Primarily photosynthetic organisms * all colors but blue-green (cyanobacteria) * Ex. phytoplankton and kelp * **_Slime Molds_** * formerly placed in fungi, now considered protists * **are arranged in a coenocytic (many nuclei) mass of protoplasm** * life cycle = animal like and plant like stages * Produce asexually by sporulation

Answer 197

* **Considered nonphotosynthetic plants** (ie. they resemble plants in that they are eukaryotic, multicellular, differentiated and nonmotile) * have **_cell walls composed of chitin_** and not cellulose, used by plants * **Eukaryotes and primarily multicellular** * **heterotrophs** * May be: **saprophytic** (decomposing dead organic material) or **parasitic** (extracting nutrients from hosts) * **Reproduces asexually** by **_sporulation_** or intricate sexual processes * **Mushrooms, yeast, and lichens**

Answer 198

* **nonmotile photosynthetic** * make own energy = **_autotrophs_** * tissue layers contain **chloroplasts** for manufacturing carbs. * **absorption tissues,** like roots and simpler **rhizoids** * **conducting or vascular tissue** transport water, minerals and nutrients to plant * waxy surround = **cuticles** * Cells are in direct contact with the external environment by means of air spaces called **stomata** * **Divisions = *_bryophytes and tracheophytes_***

Answer 199

* Bryophyta, hepatophyta and anthocerotophyta divisions (informally called bryophytes) are simple plants with **few specialized organs and tissues** * **lack** the water-conducting woody material **_(xylem)_** that support in tracheophytes * **These type of plants undergo alternation of generations** * **gametophyte** = dominante generation * the "main" plant and is larger and nutritionally independant * **Sporophyte** * smaller and shorter lived,growing off the gametophyte from the archegonium * heterotroph parasite * **_Mosses_** are classic bryophytes - sporophytes and gametophytes generations grow together * **_Liverworts_** are flat, horizontal and leaf-like plants with differentiated dorsal and ventral surfaces

Answer 200

* **_Vascular plants_** (tracheophytes) are complex plants with a **great degree of cell differentiation** * contain vascular tissues: **_Xylem_** (water-conduction) and **_phloem_** (food-conduction) * Composed of: * **_Non-seed-bearing_** * Pterophytes (ferns) * Lycophytes (club mosses) * **_Angiosperms_** * Angiosperms * Dicotyledons (dicots) * Monocotyledons (monocots) * **_Gymnosperms_** * Gymnosperms (naked-seeding plants) * Conifers (pines, spruce and firs)

Answer 201

* Two extant divisions of non-seed-bearing vascular plants: * **_Pterophytes:_** * familiar **fern** * grown from an underground stem = **rhizome,** and contain large leaves (**megaphylls**) * Ferns grow lengthwise, not in diameter, and contain xylem with **elongated tracheid cells** that transport salt and water * **_Lycophytes:_** * have roots, are nonwoody and contain **microphylle leaves**

Answer 202

* **_Angiosperms:_** * contain the **greatest number of different plant species** * have covered seeds and are most abundant of all plants * have **_flowers,_** not cones as their reproductive structure * another of **male _stamen_ produces _microspores_ (pollen grains)** while the **ovary of the female _pistil_ produces _megaspores_** * **_Dicotyledons (dicots)_** * angiosperms with **net-veined leaves and vascular bundles** around a ring within the central cylinder * contain **two cotyledons** (seed leaves) * have cambius and can be woody * flower parts in **4 to 5 multiples** * ex: maple, apple trees, potatoes, carrots, goldenrods, buttercups * **_Monocotyldons (monocots)_** * angiosperms that contain leaves with **parallel veins,** scattered vascular bundles, **seeds with single cotyledons** (single leave) * most do not have cambium and nonwoody (herbaceous) * Flower parts in **multiples of three** * ex. grasses (wheat, corn, rye, and rice), sugar cane, pinapple, irises, bananas, orchids, and palms (woody monocots)

Answer 203

* Are naked-seeded plants * gymnosperms is short-lived and microscopic * Male microspores produces pollens, carried by wind * requirement of a water env. * Presence of a specialized cambium tissue allows for secondary growth of secondary xylem (wood) and secondary phloem * grow in diameter as well as length and woody * not herbaceous (green with soft stems) * Most are **evergreens** (non-deciduous) * Divisions: * **conifers** * largest group of gymnosperms * **pines, spruces, and firs** * Cycadophyta **_(cycads)_** * stout, cylindrical trees with pinnate **(feather-like) leaves** * Gnetophyta **_(gnetophytes)_** * widely varying properties but tend to be **vine like** * Ginkgophyta **_(ginkgo)_** * only has one extant species, **Ginkgo tree,** grows pungent seens and sometimes used in **herbal medicines**

Answer 204

* Multicellular, generally motile, heterotrophic organisms that have differentiated tissues * with **exception of some parasites** like the **_tapeworm,_** animals ingest bulk food, digest them and eliminate remains * usually **require movement for nutrients**, but s**ome are _sessile_ (stationary)** and create currents to trap food * Simple multicellular: * sponges, coelenterates, flatworms, minimal differentiation * direct contact with outside env. * few systems: digestive and reproductive * Advanced animals: specialized tissues and systems * Most have a right and left sides that mirror image one another = **_bilateral symmetry_** * Some such as echinoderms and cnidarians have **_radial symmetry_**

Answer 205

* **_Porifera:_** contains sea **sponges**, have two layers of cells, pores, and low degree of cellular specialization. * usually **sessile** (cannot move for food) * **_Cnidaria:_** contain a digestive sac that sealed at one end. Two layers of cells are present, **extoderm and endoderm** * specialized featers: **tentacles, stinging cells and nerve nets** (ex. hydra, jellyfish, anemones, and coral) * **_Platyhelminthes:_** **flatworms** with ribbon-like, bilaterally symmetrical bodies. **Three germ layers** * do **not have circulatory systems**, and nervous systems consist of eyes and anterior brain ganglion and pair of longitudinal nerve cords * **_Nematoda:_** **Roundworms,** long digestive tubes and anuses. Solid mesoderm. * **lack circulatory system**, possess nerve cords and anterior nerve rings (ex. hookworms, trichina, and free-living soil nematodes) * **_Annelida:_** segmented worms that possess a **coelom (true body cavity)** in mesoderm. Have **well-defined systems,** nervous, circulatory and excretory systems * ex. earthworms and leeches * **_Mollusca:_** soft-bodied and possess mantels that often secrete calcareous **(calcium carbonate) exoskeletons** * breathe by gills and contain chambered hearts, blood sinuses, ventral nerve cords (ex. clams, snails, squid) * **_Arthropoda:_** **jointed appendages**, chitinous exoskeletons, open circulatory systems (sinuses) * Classes: * **insects:** spiracles and tracheal tubes for breathing, have three pairs of legs * **arachnides:** four pairs of legs and book lungs (scorpions and spiders) * **crustaceans:** segmented bodies veriable appendage numbers, also have gills (ex.lobsters, crayfish and shrimp) * **_Echinodermata_**: spiny, radially symmetrical, water-vascular system, **capacity for regeneration parts** * link between echinoderms and chordates. (ex. starfish and sea urchin) * **_Chordata:_** **stiff dorsal rod, notochord,** during development. Paired gills slits and tail extending beyond anus. * Lancelets and tunicates (amphioxus) are chordates) **- no backbone** * **_Vertebrates:_** include **amphibians, reptiles, birds, fish, and mammals** * possess bones, vertebrae, forming the backbone. replace notochords of the embryo and protect nerve cord

Answer 206

* **_Agnatha:_** **jawless fish,** instead have a suckling mouth (ex. lamprey and hagfish) * **_Chondrichthyes:_** **Cartilaginous fish** possess jaws and teeth (ex. sharks) * **_Osteichthyes:_** **bony fish** and most prevalent. have scales and lack notochord in the adult form. cartilage is replaced by bony skeleton (ex. sturgeon, trout and tuna) * **_Amphibia:_** **larval stages found in water but adult stages live on land.** Possess gills and a tail with no legs, adults have lungs, two pairs of legs, no tail and three chambered heart and no scales (frogs, salamander, toad and newt) * **_Reptialia_**: **live on land,** breathe air by lungs, lay leathery eggs, and utilize internal fertilization. **cold-blooded (poikilothermic)** have scales and three-chambered heart (ex. turtle, lizard, snake and crocodile * **_Aves:_** **birds,** four chambered heart. **warm blooded (homeothermic)** eggs are surrounded by shell (ex. hen and eagle) * **_Mammalia:_** **warm-blooded** and feed their offspring with milk. * ***monotremata*** order lay leathery eggs, horny bills and produce milk but no nipples (ex. duck-billed platypus and spiny anteater) * ***Marsupials***: infraclass of pouched mammals (kangaroo and opossum) * **Placentalia:** embryos that develop fully in the uterus (humans, bats, whale, mouse)

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* do not carry out physiological or biochemical processes outside of a host * may be considered **nonliving** * Viruses have **lytic and lysogenic life cycles** * They contain **either DNA or RNA** and some essential enzymes surrounded by a protein coat * Exclusively infect bacteria - **bacteriophages**

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* **_Dermis_** * Blood supply and specialized cells * **_Epidermis_** * Keratinocytes * differentiate into protective, waterproof cells called **corneocytes**

Answer 209

N-terminus

Answer 210

To dilate the blood vessels

Answer 211

* Humeral * antibody production * Cell-mediated * cells that combat fungal and viral infections

Answer 212

* Nonspecific defense mechanism * White blood cells are activated they release chemical, such as **histamine,** that activate the immune response by: * dialating and increasing permeability of blood vessels * Often accompanied by an increase in body temperature, **fever**

Answer 213

* Found in extravascular space of most tissue * **_Lymph node and spleen_** serve as a reservoirs of white blood cells and filter for lymph * removing antigen-presenting cells and foreign matter and activating the immune system when necessary

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* **_Innate immunity = rapid response_** * Body's initial, generalized defense * does not require cells that are aquired from previous infections * not a specific response * **anatomical features (skin)** * **physiological response (fever, pH change, enzymes)** * **phagocytic cells (monocytes, neutrophils, macrophages)** * **Inflammation** * **_Adaptive Immunity = slow response_** * Acquired or specific = cells that recognize self versus nonself cells * Contain memory components aquired through previous exposure * **Lymphocytes (B and T cells)** * **Plasma cells** * **Antigen-presenting cells (macrophages, B cells)**

Answer 215

* Attracted to site of injury, where they phagocytize antigens and antigenic material * **_Neutrophils:_** * Most common and first responders * **Attracted to cytokines** and in tern attract additional WBC's once they arrive * Mainly **adapted to attack bacteria** * Elevated during acute stage of inflammation and are main component of **pus** * **_Eosinophils:_** * less common * **Allergic and asthmatic** response or presence of **endoparasites,** live on skin, such as **helminth** (type of parasitic worm) * **_Basophils (mast cells)_** * Least common * **Allergic** response and often are responsible for the **release of histaminc**, stimulate blood vessel dialation * Also for **ectoparasite**, live on surface of skin, fleas and ticks

Answer 216

* Are large, long-lived immune cells that can differentiate into macrophages and dendritic cells * **_Macrophages_** * **Phagocytize dead cells and pathogens** * If pathogen is ingested, its antigens are then presented on the surface of macrophage to stimulate other immune response, mount a **specific invading pathogen** * **_Dendritic Cells_** * Focused on precessing antigens and presenting them to other immune cells * important **link between innate and adaptive immune system** * Found in areas of body in contact with **external env**. (skin, intestine, mucous mem.)

Answer 217

T Lymphocytes B Lymphocytes

Answer 218

* Specific immunity, reactivate to one specific antigen * If infection with the previous infection, antigen present, the antigen form the pathogen will be presented by a major histocompatibility protein complex (MHC) on the surface of the antigen-presenting cell, indecating T cell should perform its function * Vast majority of T cells are destroyed, dont react to MHC or react too much (apoptosis) * Two major MHC: MHC I and MHC II

Answer 219

* **_Cytotoxin T (Tc) cells (CD8+T cells)_** * Contain 8 proteins (CD) * Recognize and respond to antigens presented by **MHC I** complex * Come from cells impacted by **viruses or developing tumors and signal Tc to destroy cells** * **_T helper (T_H) cells (CD4+ T cells):_** * 4 CD protein * Recognize and respond to antigens presented by **MHC II** complexes * Activated T_H cells **release cytokines** to stimulate the immune response, causing other white blood cells to mature and attack * **_Natural Killer T (NKT) cells_** * Behave similarly to Tc and T_Hcells but **respond to antigens presented by other types of cells**

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Serve to tone down T cell response to self cells or following an infection

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* **_T cells:_** * **Begin in bone marrow**, where precursor cells form * Travel to the **thymus** where they mature * **_B cells:_** * Begin and end development in **Bone Marrow**

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* When stimulated, they create and express antibodies (immunoglobulins) that have a high affinity for the antigen expressed by the stimulating T lymphocytes * Immunoglobulin have a very particular structure and utilize the specificity of this structure to aid in the targeted destruction of pathogens * Like T cells, B cells an also stimulate the formation of memory cells *

Answer 223

Not cells, various chemicals, hormones, and enzyme supplement the action of the cells and serve equally important roles

Answer 224

* Large proteins secreted by B cells known as antibodies (immunoglobulins) provide specific, targeted response to a given antigen * **Exist in the form of a Y** * antigen binding sites at the **N-terminus end** (two ends of the Y) * Each side of structure consists of two chains (light and heavy chain held by **disulfide bonds)** * **Variable portions of the structure is the antigen-binding region** (inside the Y)

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* **_Active Immunity:_** * As a result of an immune response to an **exposure of a pathogen or antigen,** like infection * Could also be from a **vaccine** that stores "nonself" memory * **_Passive Immunity:_** * **Transfer of antibodies** from one individual to another: * **Pregnancy** * Or injection of **gamma globulin**, fractions of the blood containing antibodies * Effective immediately, but once no longer circulating, the **immunity is lost**

Answer 226

cells that support and protect the neurons

Answer 227

* **_Astrocytes:_** * Maintain the integrity of the blood-brain barrier, absorbe nutrients and dissolved gas and absorb and recycle neurotransmitters * **_Oligodendrocytes:_** * Myelinate CNS axons as well as provide structural framework for the CNS * **_Microglia:_** * Remove cellular debris and pathogens * **_Ependymal Cells:_** * Line and brain ventricles and aid in the production, circulation and monitoring of cerebral spinal fluid

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* **_Satellite cells:_** * Surround the neuron cell bodies in the ganglia * **_Schwann cells:_** * Enclose the axons in the PNS and aid in the myelination of some peripheral axons

Answer 229

see attached

Answer 230

* **_Curare:_** * **Blocks postsynaptic nicotinic acetylcholine receptors,** such as those on muscles, so acetylcholine is unable to interact with them. This leads to muscle relaxation and paralysis by blocking the ability to constrict muscles * **_Botulinum toxin:_** * **Prevents the release of acetylcholine** from the presynaptic membrane and also results in paralysis * **_Anticholinesterases:_** * Used as nerve gases and in the insecticide parathion. These inhibit the activity of the acetylcholinesterase enzyme responsible for degrading acetylcholine released int he synapse. Results is a**cetylcholine not degraded** and continues to affect the **post synaptic membrane**. Therefore, **no coordinated muscular contractions can take place**

Answer 231

Forebrain Midbrain Hindbrain

Answer 232

* Forebrain = ***_Prosencephalon_*** * Consists of the Telecephalon and Diencephalon * **_Telecephalon:_** * **Cerebral cortex** **** * gray matter on surface * Sensory and motor responses * _olfactory bulb - smell_ * **_Diencephalon:_** * **Thalamus** * **relay and integration center** for the spinal cord and cerebral cortex * **Hypothalamus** * controls **visceral function** * hunger, thirst, sex trive, water balance, blood pressure and temperature * endocrine system control

Answer 233

* Midbrain = **_Mesencephalon_** * Relay center for visual and auditory impulses and motor control * **tectum and tegmentum**

Answer 234

* Hindbrain = ***_Rhombencephalon_*** * aka **brain stem** (midbrain, pons, medulla) * Posterior part of the brain that consists of the cerebellum, pons and medulla * **_Cerebellum:_** * Modulate **motor impulses** initiated by the cerebral ortex * important for maintenance of **balance, hand-eye coordination, and the timing of rapid movement** * **_Pons:_** * acts as a **relay center** to allow the **cortex to communicate** with the **cerebellum** * **_Medulla_** * Controls vital function: **breating , heart rate, and gastrointestinal activity**

Answer 235

increase in frequency

Answer 236

a simple twitch is repeatedly generated

Answer 237

Cardiac and skeletal muscles

Answer 238

smooth muscle

Answer 239

see attached

Biology New Information Flashcards

(271 cards)