Biology Flashcards
(385 cards)
1
Q
;Describe the Cell Theory (4)
A
- The cell theory states that all living things are composed of cells
- Cells are the basic fundamental unit of life
- Cells arise only from pre-existing cells
- Cells carry their genetic info in the form of DNA
2
Q
(T/F) Electron microscopy can be used for the study of living specimens
A
False, preparation requirements kill the specimen
3
Q
What type of lab method can be used to separate cells without destroying them?
A
Low speed centrifugation can separate cells on the basis of type without destroying them
4
Q
(T/F) Differential centrifugation can be used to separate cell structures with similar densities
A
False, different densities are required for separation
5
Q
Name the two distinct groups in which all cells can be categorized
A
All cells can be categorized as either prokaryotes or eukaryotes
6
Q
What is the key differentiating criterion between prokaryotic and eukaryotic cells?
A
Eukaryotic cells have membrane-bound organelles; however, prokaryotic cells do not
7
Q
(T/F) Bacteria and viruses are examples of prokaryotic cells
A
False, bacteria are prokaryotic while viruses are non-living acellular structures
8
Q
Describe bacterial DNA
A
Bacterial DNA consists of a single circular chromosome
9
Q
(T/F) Bacteria contain ribosomes
A
True, but prokaryotic ribosomes are smaller than eukaryotic ribosomes
10
Q
Name the components of a typical bacterial cell
A
Cell wall, cell membrane, cytoplasm, ribosomes, flagella, and DNA
11
Q
Where does respiration occur in the bacterial cell?
A
The cell membrane is the site of respiration in bacteria
12
Q
(T/F) All multicellular organisms are composed of eukaryotic cells
A
True
13
Q
Which type of eukaryotic cells have a cell wall?
A
Plant cells and fungal cells have a cell wall
14
Q
Is the interior of a cell membrane hydrophilic or hydrophobic?
A
The interior of a cell membrane is hydrophobic
15
Q
Label the parts of the cell membrane (B7)
A
Top - polar heads
Middle - non-polar tails
16
Q
What is the function of a transport protein?
A
A transport protein helps move polar molecules and certain ions across the cell membrane
17
Q
What is a membrane receptor?
A
A membrane receptor is a protein (or glycoprotein) that binds to molecules in the extracellular environment
18
Q
Can small polar and non-polar molecules easily cross the cell membrane?
A
Yes, because of their size, small polar and non-polar molecules can easily traverse the cell membrane
19
Q
How does a large charged molecule cross the cell membrane?
A
A large charged particle usually crosses the cell membrane with the help of a carrier protein
20
Q
(T/F) The nucleus is surrounded by a single-layered membrane
A
False, the nuclear membrane is double-layered
21
Q
How is material exchanged between the nucleus and the cytoplasm?
A
The nuclear membrane contain nuclear pores that selectively allow for the exchange of materials
22
Q
What is a histone?
A
A histone is a structural protein complexed with eukaryotic DNA to form a chromosome
23
Q
What is the function of the nucleolus?
A
The nucleolus synthesizes ribosomal RNA (rRNA)
24
Q
What is the function of a ribsome?
A
A ribsome is the sight of protien translation (assembly) during protiein synthesis
25
What is the general function of endoplasmic reticulum?
Endoplasmic reticulum is involved in the transport of materials throughout the cell
26
(T/F) Proteins synthesized by RER are secreted directly into the cytoplasm
False, they are secreted into the cisternae of RER and then sent to smooth ER, where they are secreted into vesicles
27
What is the function of the Golgi apparatus?
The Golgi apparatus receives vesicles from smooth ER, modifies them, and repackages them into vesicles for distribution
28
What happens to a secretory vesicle after it is released from the Golgi?
A secretory vesicle from the Golgi Fused with the cell membrane to release its contents via exocytosis
29
(T/F) Vesicles are membrane-bound sacs involved in transport and storage of cellular materials
True
30
What is a lysosome?
A lysosome is a membrane-bound vesicle that containshydrolytic enzymes involved in intracellular digestion
31
(T/F) Lysosomes fuse with endocytotic vesicles and help digest their contents
True
32
How does the pH in the interior of a lysosome compare with the pH in the rest of the cell?
The interior of a lysosome is acidic and therefore has a lower pH than the rest of the cell
33
What would happen if a lysosome released its contents into the cytoplasm?
The hydrolytic enzymes of the lysomsome would digest the organells and kill the cell. This process is known as autolysis
34
What is the function of mitochondria?
Mitochondria are the sites of aerobic respiration and supply most of the cell's energy
35
(T/F) Mitochondria and chloroplasts are similar structures
True
36
What is the function of a cell wall?
A cell wall protects the cell from external stimuli and desiccation
37
What is the function of centrioles?
Centrioles are involved in spindle formation during cell replication
They are only found in animal cells
38
What is a centrosome?
The centrosome is the region of a cell that contains the centrioles
39
What is the function of cytoskeleton?
Gives mechanical support, maintains the cell's shape, and functions in motility
40
(T/F) Simple diffusion is a passive process that requires energy
False, simple diffusion is a passive process and therefore DOES NOT require energy
41
Define osmosis
Osmosis is the simple diffusion of water from a region of lower solute concentration to a region of higher solute concentration
42
What would happen to a cell if it were put in a hypertonic solution?
A hypertonic solution would cause water to flow out of a cell and cause the cell to shrink
43
(T/F) A hypotonic solution will cause water to flow into a cell, causing it to swell
True
44
Define isotonic
A medium and cell are said to be isotonic when the solute concentrations of the medium and the cell are equal
45
Define facilitated diffusion
Facilitated diffusion is the net movement of dissolved particles down their concentration gradient with the help of carrier molecules
46
(T/F) Facilitated diffusion requires energy
False, all forms of diffusion, including facilitated, are passive processes
47
Define active transport
Active transport is the net movement of dissolved particles against their concentration gradient eith the help of carrier molecules.
This process requires ATP
48
(T/F) Active transport requires energy
True
49
What is endocytosis?
A process in which the cell membrane invaginates, forming an intracellular vesicle containing extracellular medium
50
What is exocytosis?
A process in which a vesicle within the cell fuses with the cell membrane and releases its contents to the extracellular medium
51
(T/F) The induced fit hypothesis holds that a substrate causes a conformational change in its corresponding active site to facilitate substrate binding
True
52
What is a coenzyme?
A coenzyme is an organic factor for an enzymatic reaction (eg vitamin)
53
(T/F) All enzymes in the body are proteins
True
54
What is the optimal temperature for most enzymes in the body?
37ºC
55
What is a photoautotroph?
A photoautotroph is an organism that can harness sunlight to create energy via photosynthesis (eg plants)
56
What is the net reaction for glycolysis?
Glucose + 2ADP + 2Pi + 2NAD+ → 2 Pyruvate + 2ATP + 2NADH + 2H+ + 2H2O
57
Does oxidation result in the loss or gain of electrons?
Oxidation refers to the loss of electrons
OIL RIG
Oxidation Is Loss
Reduction is Gain
58
What are the energy carrier molecules for a cell's metabolic processes?
ATP, NAD+, NADP+, and FAD
59
How does ATP store energy?
ATP stores energy in its high-energy phosphate bonds
60
How do NAD+, NADP+, and FAD store energy?
NAD+, NADP+, and FAD store energy in high-potential electrons
61
What happens to the number of electrons when a reactant gets reduced?
Reduction results in the gain of electrons
OIL RIG
Oxidation is Loss
Reduction is Gain
62
(T/F) Glycolysis results in substrate level phosphorylation of ADP
True
63
Is glycolysis an aerobic or anerobic process?
Glycolysis is an anaerobic process
64
What are the possible products of fermentation?
The products of fermantation are either ethanol or lactic acid
65
When does a cell rely on fermentation for its energy needs?
A cell utilizes fermentation in an anaerobic (oxygen deficient) environment
66
What is the net gain in ATP from cellular respiration for eukaryotes and prokaryotes?
Eukaryotes = 36ATP
Prokaryotes = 38ATP
67
(T/F) Cellular respiration requires aerobic conditions?
True
68
What are the three stages of cellular respiration?
Pyruvate decarboxylation
Citric acid cycle (Krebs)
Electron Transport Chain (ETC)
69
(T/F) During pyruvate decarboxylation, a molecule of CO2 is lost, leaving acetyl CoA
True
70
One molecule of glucose requires how many turns of the Citric Acid Cycle?
2
71
How many ATP, NADHm and FADH2 are created in one turn of the citric acid cycle?
1 ATP
3 NADH
1 FADH2
72
What is a cytochrome?
A cytochrome is a molecular electron carrier involved in oxidative phosphorylation
73
When and where does oxidative phosphorylation occur?
Oxidative phosphorylation occurs at the inner mitochondrial membrane during the electron transport stage of cellular respiration
74
Does the ETC require oxygen?
Yes, the final acceptor of the electrons is O2, which then forms water
75
(T/F) The ETC generates a proton gradient across the inner mitochondiral membrane
True
76
Where does glycolysis occur?
Glycolysis occurs in the cytoplasm
77
Where does the citric acid cycle occur?
Inner Mitochondrial Matrix
78
(T/F) If glucose is unavailable, the body can use carbohydrates, fats, and proteins to create energy
True
79
What are the four stages of the cell cycle?
G1, S, G2, and M
80
When do a cell's chromosomes replicate?
The chromosomes replicate during S (synthesis) stage of interphase
81
What is the order of the four stages of mitosis?
Prophase
Metaphase
Anaphase
Telophase
82
What is a chromatid?
A chromatid is one half of a replicated chromosome.
Sister chromotids are attached by the centromere.
83
In which mitotic phase does spindle formation occur?
Spindle formation occurs during prophase
84
In which mitotic phase are the chromosomes lined up in the equatorial plane?
The chromosomes seperate during anaphase
85
In which mitotic phase does cytokinesis occur?
Cytokinesis occurs during telophase
86
How many chromosomes are in a human diploid cell?
46 chromosomes
87
How many chromosomes are in a human haploid cell?
23 chromosomes
88
What are the 4 types of asexual reproduction?
Binary Fission
Budding
Mitosis
Parthenogenesis
89
What is parthenogenesis?
The development of an egg into an embryo without fertilization
90
(T/F) Homologous chromosomes code for different traits
False, homologous chromsomes code for the same traits
91
In what phase of meiosis would one find a tetrad?
Tetrads exist in Prophase 1
92
(T/F) Synapsis and crossing over result in genetic recombination
True
93
Name the different structures of the male reproduction tract.
SEVEN UP
SEminiferous Tubules
Epididymis
Vas Deferens
Ejaculatory Duct
(nothing)
Urethra
Penis
94
During what stage of development does Inner Cell Mass occur?
Blastula
95
During what stage of development does Archenteron occur?
Gastrula
96
During what stage of development does the Notochord occur?
Neurula
97
During what stage of development does the Trophoblast occur?
Blastula
98
During what stage of development does the Blastopore occur?
Gastrula
99
During what stage of development does the Neural fold occur?
Neurula
100
What structures arise from ectoderm?
Ectoderm - integument, lens of the eye, and nervous system
101
What is the integument?
a tough outer protective layer, especially that of an animal or plant.
102
What structures arise from endoderm?
Endoderm - epithelial linings of digestive and respiratory tracts, parts of the liver, pancreas, thyroid, and bladder
103
What structures arise from mesoderm?
Mesoderm - musculoskeletal system, circulatory system, connective tissue, excretory system, and gonads
104
(T/F) The placenta and umbilical cord are responsible for fetal respiration, nutrition, and waste removal
True
105
(T/F) Adult hemoglobin has a higher affinity for oxygen than fetal hemoglobin
False, fetal hemoglobin has a higher affinity for oxygen
106
What is the function of the ductus venosus?
The ductus venosus shunts blood away from the fetal liver
107
What is the funtion of the foramen ovale?
The foramen ovale diverts blood away from the pulmonary arteries and into the left atrium
108
What is the function of the ductus arteriosus?
The ductus arteriosus shunts blood directly from the pulmonary artery into the aorta
109
(T/F) The allantois and yolk sac form the basis of the umbilical cord?
True
110
From what structure does the placenta originate?
The placenta originates from the chorion
111
What are the functions of the skeleton?
The functions of the skeleton are physical support, protection of delicate organs (eg brains), source of blood cells (ie bone marrow)
112
What are the two major components of the skeleton?
The major components of the skeleton are cartilage and bone
113
What are the two types of bone?
The two types of bone are compact bone and spongy bone
114
What is the function of an osteoclast?
Osteoclasts are involved in bone reabsorption
115
What is the function of an osteoblast?
Osteoblasts are involved in bone formation
116
(T/F) Endochodral ossification is the replacement of cartilage with bone?
True
117
What is intramembranous ossification?
Intramembranous ossification is the transformation of mesenchymal tissue into bone
118
What is the function of a ligament?
Ligaments connect bone to bone and strengten joints
119
During contraction, what happens to the width of the A-band?
The A band is always of constant width
120
During contraction, what happens to the H zone and I band?
The H zone and the I band contract and decrease in length
121
(T/F) The release of Ca2+ by the sarcoplasmic reticulum initiates muscle contraction
True
122
(T/F) The sarcoplasmic reticulum must uptake Ca2+ for relaxation to occur
True
123
(T/F) A muscle fiber exhibits an "all-or-nothing" response
True
124
Which component of the nervous system innervates smooth muscle?
Smooth muscle is innervated by the autonomic nervous system
125
Which types of muscle are striated?
Cardiac and skeletal muscle are striated
126
Which muscles are under involuntary control?
Smooth and cardiac muscle
127
Which types of muscle display myogenic activity?
Cardiac and smooth muscle display myogenic activity
128
What is the role of calcium in the initiation of sarcomere contraction?
Calcium binds with troponin, which causes a conformational shift in tropomyosin, expressing the myosin binding site
129
Which compound is needed to release myosin from its binding site on actin?
ATP is needed to release myosin from its binding site on actin
130
Name the structures of the human alimentary canal (in order)
Oral cavity
Pharynx
Esophagus
Stomach
Small Intestine
Large Intestine
131
What enzyme does saliva contain and what does it digest?
Saliva contains salivary amylase, which digests starch (carbohydrates)
132
What is peristalsis?
Peristalsis is defined as the wave-like contractions that propel food through the digestive tract
133
What two sphincters separate the stomach from the rest of the alimentary canal
The cardiac sphincter and the pyloric sphincter
134
What are the three segments of the small intestine?
The small intestine is divided into the duodenum, jejunum, and ileum
135
Which segment(s) of the small intestine is/are primarily responsible for digestion?
The duodenum is primarily responsible for digestion
136
Which segment(s) of the small intestine is/are primarily responsible for absorption?
The jejunum and ileum are primarily responsible for absorption
137
Why is pancreatic juice basic (high pH)?
Pancreatic juice contains bicarbonate ion, which serves to neutralize the acidic chyme from the stomach.
This is necessary because pancreatic enzymes work best at a slightly basic pH
138
(T/F) Bile is manufactured in the liver, stored in the gall bladder, and facilitates lipid digestion
True
139
What are the three components of the large intestine?
The large intestin is divided into the cecum, colon, and rectum
140
What is the primary function of the large intestine?
The large intestine functions primarily to absorb water and salts
141
Where does protein digestion begin?
Protein digestion begins in the stomach
142
Where does lipid digestion begin?
In the small intestine
143
Which compoent of the nervous system inhibits digestion?
The sympathetic nervous system inhibits digestion
144
Which component promotes digestion?
The parasympathetic nervous system
145
Where does chymotrypsin function and what nutrient does it digest?
Small Intestine
Proteins
146
Where does pepsin function and what nutrient does it digest?
Stomach
Protein
147
Where does lipase function and what nutrient does it digest?
Small Intenstine
Lipids
148
Where does sucrase function and what nutrient does it digest?
Stomach
Starch
149
Where does trypsin function and what nutrient does it digest?
Stomach
Protein
150
Where does Carboxypeptidase function and what nutrient does it digest?
Stomach
Protein
151
Where does Maltase function and what nutrient does it digest?
Stomach
Starch
152
Where does salivary amylase function and what nutrients does it digest?
Mouth
Starch
153
What are the three distincy types of muscle in mammals?
Skeletal
Cardiac
Smooth
154
What is the sarcoplasmic reticulum?
A modified endoplasmic reticulum that stores calcium ions (in a muscle cell)
155
(T/F) Within a sarcomere, thick filaments are made of actin and thin filaments are made of myosin
False, thin filaments are made of actin and thick filaments are made of myosin
156
What is the correct sequence of the respiratory tract?
Nares
Pharynx
Larynx
Trachea
Bronchi
Bronchioles
Alveoli
157
Which part of the brain controls breathing?
The medulla oblongata controls breathing
158
(T/F) The diaphragm contracts during exhalation
False, the diaphragm relaxes during exhalation and contracts during inhalation
159
(T/F) All arteries carry oxygenated blood and all veins carry deoxygenated blood
False, pulmonary arteries and umbilical arteries carry deoxygenated blood while pulmonary veins and umbilical veins carry oxygenated blood
160
(T/F) The right side of the heart pumps blood into the pulmonary circulation and the left side pumps blood into systemic circulation
True
161
Starting with the right atrium, trace the path of blood flow throughout the body
Right atrium, Right ventricle, Pulmonary arteries , Pulmonary capillaries, Pulmonary veins, Left atrium, Left ventricle, Aorta, Arteries, Arterioles, Capillaries, Venules, Veins, Vena Cava
162
Which valve separates the right atrium and right ventricle?
The tricuspid valve seperates the right atrium from the right ventricle
163
Which valve separates the left atrium and left ventricle?
The mitral valve separates the the left atrium from the left ventricle
164
(T/F) Systole is when the heart relaxes and diastole is when the ventricles contract
False, the ventricles contract during systole and the heart relaxes during diastole
165
What is plasma?
Plasma is the liquid component of blood
166
What are the cellular components of blood?
The cellular components of blood are erythrocytes (red blood cells), leukocytes (white blood cells), and platelets
167
What is the function of a macrophage?
A macrophage phagocytizes foreign matter
168
What are the four blood types?
A
B
AB
O
169
Which blood type is considered to be a universal donor?
O
170
Which type of blood is the universal recipient?
AB
171
What is the Rh factor?
An antigen on the surface of RBCs
172
How can the Rh factor complicate pregnancy?
Following the birth of an Rh+ child, and Rh- mother develops antibodies to the Rh factor. These antibodies can attack the blood cells of any future Rh+ fetuses carried by the mother
173
(T/F) Platelets play a key role in the immune response
False, platelets are key players in clot formation
174
Which proteins are essential for proper clotting?
Thrombin and fibrin are essential for clot formation
175
What is the function of immunoglobins (antibodies)?
Antibodies attract other cells that can phagocytize an antigen or cause the antigens to clump together
176
(T/F) Skin, ciliated mucosa, macrophages, and inflammatory responses are all expamples of nonspecific defense mechanisms
True
177
What happens to interstitial fluid that doesnt diffuse into a capillary?
Excess interstitial fluid is picked up the lymphatic system and returned to the circulatory system
178
Define homeostastis
The maintenance of a stable internal environment
179
What are the primary homeostatic organs in mammals?
The primary homeostatic organs are the kidneys, liver, large intestine, and skin
180
What are the three regions of the kidney?
The three regions of a kidney are the pelvis, medulla, and cortex
181
(T/F) A nephron is situated such that the loop of Henle runs through the medulla
True
182
What is the primary purpose of the kidney?
The primary purpose of the kidneys is to regulate salt and water cancentration in the blood
183
Where are amino acids, glucose, and vitamins reabsorbed in the nephron?
Amino acids, glucose, and vitamins are reabsorbed into proximal convoluted tubule
184
Where in the loop of Henle does water passively diffuse out?
Water passively diffuses out of the descending limb
185
(T/F) Water passively diffuses into the ascending limb
False, the ascending limb is impermeable to water
186
(T/F) Aldosterone stimulates the reabsorption of Na+ and H2O from the distal tubule and collecting duct
True
187
Would high levels of aldosterone result in concentrated or dilute urine?
High levels of aldosterone result in concentrated urine
188
How would low levels of aldosterone affect blood pressure?
Low levels of aldosterone lead to reduced blood plasma volume and therefore reduced blood pressure
189
Would high levels of ADH (vasopressin) result in concentrated or diluted urine?
High levels of ADH result in concentrated urine
190
Where and how does ADH affect the nephron?
ADH makes the distal convoluted tubule and collecting duct more permeable to H2O
191
(T/F) Urine leaves the kidney via the ureter and leaves the bladder via the urethra
True
192
Is urine hypertonic or hypotonic to blood?
Hypertonic
193
What are some of the functions of the liver?
Regulation of blood glucose
Detoxification of toxins
Beta-oxidation of fatty acids
Destruction of old RBCs
194
(T/F) The large intestin functions as an excretory organ by getting rid of excess salts
True
195
In which layer of the skin are sweat glands, sense organs, and blood vesssles located?
The Dermis
196
What is the difference between an endocrine gland and an exocrine gland?
Endocrine glands secrete their hormones directly into the blood stream
Exocrine glands secrete substances that are transported by ducts
197
The anterior pituitary is regulated in part by what other endocrine gland?
The hypothalamus regulates the anterior pituitary
198
Name all of the hormones secreted by the anterior pituitary gland
Growth Hormone (GH)
Prolactin
Adrenocorticotropic Hormone (ACTH)
Thyroid Stimulating Hormone (TSH)
Luteinizing Hormone (LH)
Follicle-Stimulating Hormone (FSH)
199
(T/F) Growth hormone promotes bone and muscle growth
True
200
What is the function of prolactin?
Prolactin stimulates the produciton of breast milk
201
What is the target gland of ACTH?
Adrenal Cortex
202
What is the fucntion of TSH?
TSH causes the thyroid to uptake iodine and produce thyroid hormone
203
(T/F) LH and FSH are secreted only in females
False, LH and FSH are produced and secreted in males as well as females
204
Name the hormones synthesized by the posterior pituitary
None. The posterior pituitary stores hormones (oxytoxin and ADH) that are synthesized in the hypothalamus
205
What two hormones are released by the posterior pituitary and what are their functions?
Oxytocin increases the strength of contractions during childbirth. ADH promotes the absorption of water in the nephron
206
(T/F) The hypothalamus regulates both the anterior and the posterior pituitary through hormone secretion and neurosecretory cells
True
207
Name the hormones secreted by the thyroid gland
The thyroid gland secretes thyroxine and triiodothyronine as well as calcitonin
208
How do thyroid hormones affect metabolism?
Thyroid hormones increase metabolism
209
How does calcitonin affect the level of Ca2+ in blood plasma?
Calcitonin decreases blood plasma calcium
210
What hormone does the parathyroid gland produce and what is its function?
The parathyroid secretes parathyroid hormone, which serves to increase blood plasma calcium
211
Name the three types of hormones secreted by the adrenal cortex
Glucocorticoids, mineralocorticoids, and cortical sex hormones
212
What is the function of cortisol?
Cortisol is a glucocorticoid that increases the blood's glucose level
213
What important mineralocorticoid is released by the adrenal cortex?
Aldosterone is an important meneralocorticoid released by the adrenal cortex
214
Which endocrine gland secretes epinephrine and norepinephrine?
The adrenal medulla secretes epinephrine and norepinephrine
215
(T/F) Epinephrine and norepinephrine return the body to its resting state and increase nutrient absorption
False, they slow down digestion and increase the basal metabolic rate
216
What are some of the effects of epinephrine?
Increased heart rate
Increased blood glucose level
Increased blood supply to brain, muscle, and heart
Decreased digestion and excretion
217
Which endocrine organ secretes insulin and glucagon?
The pancreas secretes insulin and glucagon
218
How does glucagon affect blood glucose levels?
Increases blood glucose levels
219
How does insulin affect blood glucose levels?
Decreases blood glucose levels
220
(T/F) Too much insulin causes hypoglycemia
True
221
Which two hormones are secreted by the ovaries?
The ovaries secrete estrogen and progesterone
222
What are the four phases of the menstrual cycle?
Follicular Phase
Ovulation
Luteal Phase
Menstration
223
What is the corpus luteum?
The corpus luteum develops from a ruptured follicle in the ovary and secretes estrogen and progestrone
224
(T/F) The testes secrete testosterone
True
225
(T/F) The pineal gland secretes melatonin
True
226
What is the function of a dendrite?
A dendrite conducts nerve impulses toward the cell body
227
What is the fucntion of an axon?
An axon conducts nerve impulses away from the cell body
228
What is the composition of a myelin sheath?
In the CNS, myelin is composed of the membranes of oligodendrocytes. In the PNS, myelin is composed of the mebranes of Schwann cells
229
What protein complex is responsible for the resting potential (-70 mV) of a neuron?
The Na+ - K- pump is responsible for the neuron's resting potential
230
(T/F) In a resting neuron, Na+ concentration is higher inside the cell than outside the cell
False, Na+ concentration is higher outside a resting neuron
231
Do Na+ ions rush into or out of the cell during depolarization?
Na+ ions rush into a cell during depolarization
232
Do K+ ions rush into or out of the cell during repolarization?
During repolarization, K+ ions rush out of the cell
233
(T/F) A neuron can conduct during the refractory period
False, the neuron is unable to respond to stimulus during the refractory period
234
What is hyperpolarization?
A state where the potential across the membrane is more negative than the resting potential
235
What is saltatory conduction?
Saltatory conduction is the "jumping" of an action potential between the unmyelinated Nodes of Ranvier
236
What happens when an action potential reaches a synapse (in a mammal)?
When an action potential reaches a synapse, the elctrical signal causes the release of neurotransmitters from the presynaptic membrane into a synapse
237
What is the function of a sensory (afferent) neuron?
A sensory neuron carries impulses from sensory organs to the brain and spinal cord
238
What is the function of a motor (efferent) neuron?
A motor neuron transmits impulses from the brain and spinal cord to muscles or glands
239
Which type of neuron serves as a link between motor and sensory neurons?
Interneurons (associate neurons) link sensory and motor neurons
240
What are the two major subsystems of the nervous system?
The two major subsystems of the nervous system are the CNS and PNS
241
What are the components of the CNS?
The brain and spinal cord
242
What is the largest part of the human brain?
The cerebral cortex is the largest part of the human brain
243
What is the function of the cerebral cortex?
The cerebral cortex processes and integrates sensory input and motor response, and controls memory
244
What is the function of the hypothalamus?
The hypothalamus is responsible for visceral functions such as hunger, thirt, and sex drive
245
(T/F) The cerebral cortex is the relay center for visual and auditory impulses
False, the midbrain is the relay center for visual and auditory impulses
246
What are the components of the hindbrain?
The hindbrain is composed of the cerebellum, pons, and medulla oblongata
247
What is the function of the cerebellum?
The cerebellum is responsible for cooridination
248
What part of the brain controls autonomic activities?
The medulla oblongata controls autonomic activities
249
What are the four regions of the spinal cord?
Cervical
Thoracic
Lumbar
Sacral
250
(T/F) Dorsal root ganglia house the cell bodies of sensory root fibers
True
251
Which part of the nervous system readies the body for "fight or flight"?
The sympathetic nervous system readies the body for "fight or flight"
252
What is the function of the parasympathetic division of the nervous system?
Opposes the sympathetic divsion by slowing the body down and conserving energy
253
Which division of the nervous system inhibits digestion?
The sympathetic division inhibits digestion
254
Which type of photoreceptor cell is specialized for color vision?
Cones
255
Which type of photoreceptor cell is specialized for low light conditions?
Rods
256
What is the fovea?
The region in the retina with a high density of cones
257
What are the components of the middle ear?
The middle ear is composed of the tympanic membrane, malleus, incus, and stapes
258
What are the components of the inner ear?
The inner ear is composed of the cochlea and organ of Corti
259
What are alleles?
Different forms of the same gene.
Occupy the smae position on homologous chromosomes
260
Define genotype
Genotype refers to the genetic makeup of an individual
261
Define phenotype
Phenotype refers to the physical manifestation of an individual's genotype
262
Define homozygous
Homozygous indiviuals have two copies of the same allele for a given trait
263
Define heterozygous
Heterozygous individuals have two different alleles for a given trait.
264
Summarize Mendel's First Law (Law of Segregation)
Mendel's first law states that alleles segregate during meiosis:
* Genes exist in alternative forms (alleles)
* An individual inherits two alleles for each trait, one from each parent
* The two alleles segrege during meiosis
* If two different alleles are present, only one will be fully expressed
265
Summarize Mendel's Second Law (Law of Independent Assortment)
Mendel's second law states that alleles of unlinked genes assort independently during meiosis
266
What would the phenotypic ratio of a PP x pp cross?
P = purple
p = white
PP x pp = 100% purple
267
What would the phenotypic ratio of a Pp x Pp cross?
P = purple
p = white
Pp x Pp = 75% purple
25% white
268
What would the phenotypic ratio of a Pp x pp cross?
P = purple
p = white
Pp x pp = 50% purple
50% white
269
What would the genotypic ratio of a Pp x pp cross?
P = purple
p = white
Pp x pp = 50% Pp
50% pp
270
What would the genotypic ratio of a Pp x Pp cross?
P = purple
p = white
Pp x Pp = 25% PP
50% Pp
25% pp
271
Assuming codominance, what happens to the phenotype in the presence of two dominant alleles?
The phenotype of each allele is simultaneously displayed (eg type AB blood)
272
Red flowers crossed with white flowers yield pink flowers. What kind of dominance is protrayed in this example?
Incomplete dominance
273
(T/F) In humans, most sex-linked genes are located on the Y chromosome
False, most sex-linked genes are on the X chromosome
274
What percentafe of daghters will inherit their father's sex-linked gene?
100% of daughters will inherit their father's sex-linked gene
275
What percentage of sons wil inherit their father's sex-linked gene?
0% of sons will inherit their father's sex-linked gene
276
What percentage of sons will inherit their mother's sex-linked gene (assuming a heterozygous mother)?
50% of sons will inherit their mother's sex-linked gene
277
(T/F) Females can express sex-linked recessive trait
True, a female carrier and a male with the recessive trait will have a 25% chance of giving birth to a female child with the recessive trait
278
What is nondisjunction?
Nondisjunction is the failure of homologous chromosomes (or sister chromatids) to separate properly during cellular reproduction
279
Name the four nitogenous bases in DNA
Adenine
Cytosine
Guanine
Thymine
280
Name the purines.
Adenine and Guanine
281
Name the pyrimidines
Cytosine and Thymine
282
What is the base-pairing in DNA? How many bonds hold the bases together?
Adenine - Thymine (2 H bonds)
Cytosine - Guanine (3 H bonds)
283
Name three differences between RNA and DNA
RNA uses ribose instead of deoxyribose
RNA replaces thymine with Uracil
RNA is single-stranded
284
(T/F) DNA synthesis proceeds in the 3' to 5' direction
False, DNA synthesis proceeds in the 5' to 3' direction
285
What are the three types of RNA, and what are their functions?
Messenger RNA (mRNA) - contains the codons for peptode chain synthesis
Transfer RNA (tRNA) - transports amino acids to the ribosome during protein synthesis
Ribosomal RNA (rRNA) - structural component of ribsomes
286
What is trascription?
Transcription is the process whereby mRNA is synthesized from a DNA template
287
What is translation?
Translation is the prcoess whereby proteins are synthesized from a mRNA template
288
What is an exon?
An exon is a coding sequence on a gene
289
What is an intron?
An intron is a non-coding sequence on a gene
290
What is a codon?
A codon is a 3-base sequence on mRNA that codes for a specific amino acid
291
What is an anticodon?
An anticodon is a 3-base sequence on tRNA that is complementary to a mRNA codon
292
what are the three stages of polypeptide synthesis?
The three stages of polypeptide synthesis are initiation, elongation, and termination
293
What are the three types of base pair mutations that can occur during protein synthesis?
Types of base-pair mutations are substitutions, insertions, and deletions
294
What is a retrovirus?
A retrovirus is an RNA virus that codes for the enzyme reverse transcriptase, which uses the RNA as a template for DNA synthesis
295
What is a prophage (provirus)?
A prophage is a becterial virus that has integrated into its host cell genome
296
Describe the lytic and lysogenic cycles
Bacteriophage infection results in either a lytic or a lysogenic cycle.
A lytic cycle results in the production of new progeny that cause the cell to burst (lyse)
A lysogenic cycle results in incorportation of the viral DNA into the bacterial DNA where it remains inactive
A lysogenic cycle may progress to a lytic cycle
297
What are the three mechanisms by which bacteria can increase genetic variability?
Transformation - incorportation of foreign chromosome fragments
Conjugation - transfer of genetic material between two bacteria
Transduction - virus carries DNA between two bacteria
298
What is an operon?
An operon is a gene that regulates (bacterial) transcription
299
What is an inducible system?
An inducible system requires the presence of an inducer for transcription to occur
300
What is a repressible system?
A repressible system is in a constant state of transcription unless a corepressor is present to inhibit transcription
301
(T/F) Lamarck's theory of evolution is based on the inheritance of acquired characteristics
True
302
(T/F) Lamarckian evolution holds true in a number of different circumstances
False, acquired characteristics cannot be inherited
303
Define fitness according to Darwin
Fitness is the ability of an organism to mate and produce fertile offspring
304
What are homologous structures?
Homologous structures are similar in origin but not function (whale flippers / human arms)
305
What are analogous structures?
Analogous structures are similar in function but not a in origin (insect wings / bird wings)
306
What are vestigal structures?
A vestigal structure is a remnant structure that has lost its ancestral function (tail bone in man)
307
Given the Hardy Weinburg equation: p2 + 2pq + q2 = 1:
What does p2 represent?
p2 = frequency of homozygous dominants
308
Given the Hardy Weinburg equation: p2 + 2pq + q2 = 1:
What does 2pq represent?
2pq = frequency of heterozygotes
309
Given the Hardy Weinburg equation: p2 + 2pq + q2 = 1:
What does q2 represent?
q2 = frequency of homozygous recessives
310
Given the Hardy Weinburg equation: p2 + 2pq + q2 = 1:
(T/F) p + q = 1
True
311
What are the 5 necessary conditions for the Hardy-Weinberg equation to hold true?
1. There are no mutations taht affect the gene pool
2. The population must be very large
3. Genes in a population are equally successful at reproducing
4. Mating occurs randomly
5. There is no net migration of individuals
312
How does genetic drift differ from gene flow?
Genetic drift refers to changes in the gene pool due to chance. Gene flow refers to the changing of the gene pool due to the migration of individuals
313
(T/F) Stabilizing selection maintains a well adapted uniform character in a population
True
314
How does disruptive selection affect the phenotype of a population?
Disruptive selection favors the phenotypical extremes, leading to the expression of two or more phenotypic forms
315
How does directional selection affect the phenotype of a population?
Directional selection favors the expression of one phenotypical extreme
316
When are two populations descending from the same ancestral stock considered to be different species?
Two populations are considered to be different species when they can no longer interbreed and produce viable offspring
317
What is adaptive radiation?
Adaptive radiation is the emergence of a number of distinct lineages from a single ancestral species. The different lineages usually result when a group begins to exploit a different niche
318
Describe convergent evolution
Convergent evolution refers to the independent development of similar characteristics by non-related groups
319
Describe parallel evolution
Parallel evolution refers to the process whereby related groups independently develop similar characteristics due to analogous environmental pressures
320
Describe divergent evolution
Divergent evolution refers to the process whereby related groups independently develop dissimilar characteristics
321
(T/F) Photosynthetic organisms use CO2 and H2O to produce carbohydrates, proteins, and lipids
True
322
In what organelle does photosynthesis occur? What photosynthetic pigement is used?
Chloroplasts
Chlorophyll
323
What structures let gases in and out of the plant? What regulates the opening and closing of the structures?
Stomates
Guard cells
324
What is the net reaction for photosynthesis?
6 CO2 + 12 H2O + light energy → C6H12O6 + 6 O2 + 6 H2O
325
What happens during the light cycle?
Light energy is used to produce ATP through photophosphorylation and photolysis (splitting of water), while forming O2 and NADPH
326
What happens during the dark (Calvin) cycle?
ATP and NADPH formed during the light reaction are used to fix CO2 into organic material. Light is not required, but the dark cycle usually occurs during the day, when the light reaction provides ATP and NADPH
327
(T/F) Sugars may be synthesized once the light cycle has shut down?
True (The dark (Calvin) cycle can continue in the absence of light)
328
What molecule provides the reducing power needed during the synthesis of sugar
NADPH
329
What type of digestive system do annelids employ?
A one way, two opening digestive tract (eg worms)
330
What type of digestive system do arthropods employ?
A one-way, two opening digestive tract (eg worms)
331
What type of digestive system do coelenterates employ?
Extracellular digestion in the gastrovascular cavity (eg hydra)
332
What type of digestive system do protozoans employ?
Intracellular digestion
333
What type of respiratory system do annelids employ?
Gas exchange via diffusion through moist skin (eg worms)
334
What type of respiratory system do arthropods employ?
Gas is exchanged through respiratory tracheae which branch extensively throughout the body. Air enters and leaves the trachea via openings on the surface called spiracles (eg grasshopper)
335
What type of respiratory system do coelenterates employ?
Gas exhange via diffusion through individual cell membranes contacting aqueous environment
336
What type of respiratory system do protozoans employ?
Gas exchange via diffusion through individual cell membranes contacting aqueous environment.
337
What type of circulatory system do annelids employ?
Closed, simple circulatory system
338
What type of circulatory system do arthropods employ?
Open circulatory system
339
What type of circulatory system do coelenterates employ?
Diffusion
Cyclosis
340
What type of circulatory system do protozoans employ?
Diffusion
Cyclosis
341
What type of nervous system do annelids employ?
A primitive central nervous system with a brain composed of fused ganglia
342
What type of nervous system do arthropods employ?
A nervous system similar to that of annelids, but with specialized sense organs
343
(T/F) Coelenterates employ a nerve net as their nervous system?
True
344
What is asexual reproduction?
Any reproductive process that does not involve the fusion of gametes
345
(T/F) Binary fission (characteristic of prokaryotes) entails an equal division of cytoplasm as well as nuclear contents
True
346
(T/F) Budding entails an equal division of cytoplasm as well as nuclear contents
False. Budding is an asexual reproductive process chacteristic of yeast in which there is an equal division of genetic material and an unequal division of cytoplasm. The daughter cell may pinch off and live independently, or remain connected and live as part of the larger colony
347
What is parthenogenesis?
Development of an egg in the absence of fertilization, resulting in a haploid organism; eg. sometimes occurs in frogs
348
What type of excretory system do annelids employ?
Excrete urea through nephridia in skin
349
What type of excretory system do arthropods employ?
Produce uric acid the Malpighian tubules and eliminate in through rectum
350
(T/F) In coelenterates, ammonia and CO2 diffuse directly into the environment
True
351
(T/F) In protozoans, ammonia and CO2 diffuse directly into the environment
True
352
Place the following objects in the order in which they exist in the energy pyramid, from the top to the bottom: Secondary consumers, Producers, Sunlight, Detrivores, Primary consumers
Sunlight, Producers, Primary consumers, Secondary consumers, Detrivores
353
What are omnivores?
Omnivores are heterotrophs that consume both plants and animals
354
What role do animals have in the nitrogen cycle?
The wastes and dead reamins of plants and animals provide the ammonia (NH3) used by nitrifying bacteria to produce nitrites and nitrogen dioxide (NO2) and used by denitrifying bacteria to produce free nitrogen (N2) in the atmosphere
355
(T/F) Nitrogen fixation occurs in the stalks of leafy green vegetable plants
False. Bacteria on the roots of legumes are responsible for nitrogen fixation
356
(T/F) Chemosynthetic bacteria do not rely on photosynthesis for survival
True
357
What are the three directly biological sources of CO2 in the environment?
Respiration, photosynthesis, and the decomposition of plant and animal materials by bacteria of decay
358
Place the following in order of levels of biological organization, from smallest to largest: Biosphere, Community, Ecosystem, Organism, Population
Organism, Population, Community, Ecosystem, Biosphere
359
What are the characteristics of the population growth curve that occurs most often in nature?
The logistic growth curve is an S-shaped curve that plateaus at a valus known as K (the carrying capacity), the maximum number of organisms the environment can support as a result of the limited amount of resources
360
(T/F) In a commensalistic relationship, both organisms involved benefit
False. In a commensalistic relationship, while the non-host organism involved benefits, the host itself is neither helped nor harmed
361
What is the principle behinf ecological succession?
Organisms that live in a given environment alter the environment in ways that make living conditions less favorable for itself and more favorable for the community that succeeds it
362
What are the characteristics of the tundra?
Permanent permafrost, little water, located at of near poles, small plants, caribou, polar bears, artic foxes and hares
363
Which is the environment with the greatest diversity of plants and animals?
Tropical rain forest
364
What is a fixed action pattern?
A complex, coordinated, innate behavioral response to specific patterns of stimulation; the sign stimulus/releaser elicits the highly sterotyped behavior that must be completed once begun
365
(T/F) Imprinting can only take place during a brief critical period
True
366
In classical conditioning, in order to elicit the conditioned response from the conditioned stimulus, what must be presented along with the conditioned stimulus during the conditioning period?
In classing conditioning, the combination of presenting the conditioned stimulus along with the unconditioned stimulus (in Pavlov's case, the bell along with the meat) during the conditioning period elicits the conditioned response (in Pavlov's case, salivation) later on
367
(T/F) Operant conditioning may be used only to make an organism avoid a certain type of behavior
False. Operant conditioning may be utilized to make an organism repear or avoid a certain type of behavior, depending on whther that behavior is assoicated with a rewaard or punishment, respectively
368
(T/F) Photosynthesis occurs in the spongy layer of the mesophyll of a leaf
False. Photosynthesis occurs in the palisafe layer of the mesophyll of a leaf
369
What are the two types of structures found within a plant stem and what are their respective functions?
Xylem and phloem, which transport water and food, respectively
370
What are two types of roots?
Taproot and fibrous
371
What happens when the turgor pressure in cells decreases too much?
The plant wilts
372
What are the names of the male and female reproductive organs of a plant and their parts?
A flower's male organ is known as the stamen, which consists of the filament, a long stalk-like segment, and the anther, a small sac at the top of the filament. A flower's female organ is known as the pistil, and consists of the stigma (sticky surface that catches pollen), style (area the pollen tube grows down), and ovary (eventually forms the fruit and contains seeds called ovules)
373
Where and what types of gametes are formed in male and female plants?
Pollen is produced in the anther; the enbryo sac (containing several nuclei, including two polar nuclei and the egg nucleus) forms in the ovules
374
How many N are the plant gametes, embryo, and endosperm?
1N, 2N and 3N, respectively
375
What is phototropism?
Phototropism is the phenomenon in which plant grows toward its light source
376
What are the 5 kingdoms of living organisms?
Monera
Protista
Fungi
Plantae
Animalia
377
What are the subdivisions used in classifying an organism within a given kingdom?
Kingdom, Phylum, Subphylum, Class, Order, Family, Genus, Species
378
What is the Founder effect?
When a few individuals inhabit an isolated region, the smaller the sample size, the genetic composition of the region is less likely to represent the genentic composition of the larger population the isolated population is dervied from. This type of genetic drift in an isolated group is known as Founder effect.
379
(T/F) Convergent evolution is due to homology
False. Convergent evolution is due to analogy
380
Define heterotrophs
Dependent upon outside sources of food
381
Define coacervate droplets
a cluster of colloidal molecules surrounded by a shell of water
absorb and incorportate substances from the surrounding environment
382
Define pioneer autotrophs
organisms capable of producing some of their own nutrients
383
What are the four basic catergories that all living organisms are divided into?
Autotropic anerobes (chemosynthetic bacteria)
Autotropic aerobes (green plants and photoplankton)
Heterotropic anaerobes (yeasts)
Heterotrophic aerobes (amoebas, earthworms, humans)
384
What are the 5 lipid derivatives?
Phospholids
Waxes
Steroids
Carotenoids
Porphyrins
385
