Physiology

Question 1

Which domains and kingdoms are prokaryotes and which are eukaryotes?

Answer 1

Bacteria, Archaea, Eukarya

Question 2

What traits distinguish protists from other kingdoms?

Answer 2

they live in moist, aquatic environments, are both uni and cellular, and reproduce asexually.

Question 3

What traits distinguish plants from other kingdoms?

Answer 3

they have chloroplasts, autotrophic, and vascular tissues.

Question 4

How do plants acquire what they need to gain biomass?

Answer 4

through photosynthesis and nutrient absorption

Question 5

What traits distinguish the fungi kingdom from other kingdoms?

Answer 5

they have chitin, are decomposers, reproduce both sexually and asexually.

Question 6

How do mycorrhizae and plants benefit from their mutualistic relationship?

Answer 6

plants receive enhanced access to nutrients, and fungi receive carbohydrates and a stable habitat

Question 7

What traits distinguish the animal kingdom from other kingdoms

Answer 7

they have specialized tissues, are heterotrophic, cephalization, and sexual reproduction.

Question 8

How does the embryonic development of animals enable them to acquire specialized tissues
and structures?

Answer 8

during gastrulation 3 different germ layers are formed, cells get specialized, and then grow into complex organisms

Question 9

What is homeostasis?

Answer 9

The tendency to resist change to maintain a stable, relatively constant internal environment.a

Question 10

How do negative feedback loops maintain homeostasis?

Answer 10

They counteract changes form their set points by opposing the stimulus.

Question 11

How do positive feedback loops maintain homeostasis?

Answer 11

They maintain the direction of the stimulus, sometimes accelerating it

Question 12

How can you identify negative and positive feedback loops?

Answer 12

A negative feedback loop counteracts a stimulus while a positive feedback loop accelerates a stimulus.

Question 13

What is thermoregulation?

Answer 13

When aniammls maintain body temperature within a specific range

Question 14

What are the similarities and differences between ectotherms and endotherms?

Answer 14

Ectotherms rely on the external environment to regulate body temperature, while endotherms maintain a stable internal body temperature. But both types generate heat.

Question 15

How does the body temperature of ectotherms change with environmental
temperature?

Answer 15

As the environment gets colder, their body temperature gets colder, and as the environment gets hotter, their body temperature gets hotter.

Question 16

How does the body temperature of endotherms change with environmental
temperature?

Answer 16

Their body maintains a stable body temperature despite environmental changes.

Question 17

How do animals use insulation to thermoregulate?

Answer 17

It reduces heat flow between the animal and the environment.

Question 18

How do animals use brown adipose tissue to thermoregulate?

Answer 18

It helps aniamals generate heat

Question 19

How do animals use vasodilation and vasoconstriction to thermoregulate?

Answer 19

Vasodilation widens blood cells which increases heat loss and cools down the body. Vasoconstriction constricts blood vessels which decreases heat loss which warms up the body.

Question 20

How do animals use countercurrent exchange systems to thermoregulate?

Answer 20

warm blood flows from the heart to cold areas a body to warm up, heat gets transferred and the cold blood gets sent back up the heart, therefore maintain a stable internal body temperature.

Question 21

How do animals use behavioral modifications to thermoregulate?

Answer 21

They use them to regulate their body temperature by moving into the shade or sun, using water, or huddling together.

Question 22

What is the direction of water movement in osmosis?

Answer 22

from a low solute concentration to a high solute concentration.

Question 23

What is osmoregulation?

Answer 23

The process of maintaining salt and water balance across the membranes within the body’s fluids.

Question 24

How do blood cells change in hypertonic, isotonic, and hypotonic solutions?

Answer 24

Hypertonic: water flows out the cell = more solutes in solutions than in the cell (shrinks and shrivels)
Isotonic: Water flows in and out the cell = even concentration inside and out the cell.
Hypotonic: water flows into the cell = less solutes in the solution than the cell (grows, bursts)

Question 25

How does the osmoregulation of fish differ in freshwater vs. saltwater?

Answer 25

Freshwater: salt concentration is higher in the fish than in water, so water flows right in over gills, therefore the fish doesn't actively drink water and excretes more diluted urine. Saltwater: Salt concentration is lower in fish than in water, so water flows out of the fish. Therefore, it actively drinks more water and excretes concentrated urine.

Question 26

How do humans maintain osmoregulation using negative feedback loops?

Answer 26

For example, if you drink too much water, your water content of blood is too high. Your pituitary gland will release less ADH, which lowers the volume of water reabsorbed by the kidney. You will then have a high volume of diluted urine excreted from the bladder, which lowers the volume of water passed into the blood and regulates the water content in the blood.

Question 27

What are the four main macromolecules and their monomers?

Answer 27

Carbohydrates - monosaccharide Proteins - amino acid Lipids - fatty acid Nucleic acids - nucleotide

Question 28

How do we classify the types of animal diets?

Answer 28

Herbivores - feed on plats/algae Carnivores - feed on animals omnivores - feed of plats/algae and animals

Question 29

What feeding modes do animals use to acquire nutrients?

Answer 29

filter feeders- strain small organisms or food particles from water substrate feeders - live in or on their food fluid feeders - such nutrient-rich fluid form a living host bulk feeders - eat relatively large pieces of food

Question 30

How does food move through the human digestive system to be broken down and absorbed?

Answer 30

The mouth and salvatory glands break down food by chewing, then the esophagus pushes food down the stomach, the stomach then breaks down the proteins and moves the small intestine, in the small intestine digestive enzymes break down carbohydrates, lipids, and nucleic acids while the surface area increases to absorb nutrients. Lastly, any undigested food goes through the large intestine while it absorbs minerals and water and any waste goes through the anus and rectum.

Question 31

How do humans regulate glucose levels using negative feedback loops

Answer 31

For example, when your blood glucose levels rise, your pancreas detects this and releases insulin, this transports glucose into body cells and then the blood glucose level falls. Now going in the opposite direction when blood glucose falls, secretion of glucagon by the pancreas begins and breaks down the glucagon and releases glucose until blood glucose levels rise.

Question 32

What are the differences between Type 1 and Type 2 diabetes?

Answer 32

Type 1- insulin dependent, autoimmune diseae, appears in childhood Type 2 - non-insulin-dpedent, appears in adulthood

Question 33

What are the similarities and differences between open and closed circulatory systems?

Answer 33

open - a mixture of blood and interstitial fluid (hemolymph), the heart pumps hemolymph through vessels into sinuses, and heart relaxes and bring hemolymph back through pores closed- blood is separate from interstitial fluid, costs more energy, generates high blood pressure which is more effective for oxygen delivery and creates larger and more active animals

Question 34

How do fish circulate blood through their bodies?

Answer 34

they have an atrium (chamber that receives blood entering the heart) and a ventricle (pumps blood out of the heart. the blood travels in a single loop with a two-chambered heart. The ventricle contracts and blood moves out of the heart and to the gills to be oxygenated, then blood travels around the rest of the body to deliver oxygen before returning to the heart.

Question 35

How do amphibians circulate blood through their bodies?

Answer 35

they have a three-chambered heart (right atrium, left atrium, and ventricle). one route takes non-oxygented blood through the and skin while the other route takes oxygen-rich blood to the rest of the body.

Question 36

Why do birds and mammals have a four-chambered heart?

Answer 36

Because they are endotherms, it makes it possible by pulmonary and systemic circulation.

Question 37

How do birds and mammals circulate blood through their bodies?

Answer 37

they have a four-chambered heart (right and left atrium, aright and left ventricle). There is complete separation of oxygen-rich and oxygen-poor blood and generates very high pressure to increase the efficiency of delivering oxygen to tissues.

Question 38

How do mammals use their four-chambered heart to circulate blood?

Answer 38

the right side is oxygen-poor and the left side is oxygen-rich. Pulmonary arteries pump oxygen-poor blood to the lungs and the aorta carries the blood from the heart to the rest of the body.

Question 39

How do animals circulate blood through their bodies?

Answer 39

Arteries carry oxygenated blood from the heart to the organs throughout the body, these arteries branch into smaller arterioles. Then the capillaries allow for gas exchanges between the interstitial fluid and then the capillaries converge into venules and then continue to converge into veins. These veins carry deoxygenated blood back to the heart.

Question 40

How does the partial pressure of oxygen vary as it moves through the circulatory system?

Answer 40

external respiration - the exchange of O2 and CO2 between the air in the lungs and blood Internal respiration - the exchange of O2 and CO2 between the blood and cells

Question 41

How do fish use countercurrent exchange to perform gas exchange?

Answer 41

the countercurrent exchange of oxygen between the blood flowing in opposite directions while a partial pressure gradient is maintained. This allows for fish to breathe by acquiring O2 from the water.

Question 42

How do insects use a tracheal system to perform gas exchange?

Answer 42

It is the respiratory system in insects and is independent of the circulatory system.

Question 43

How do humans perform gas exchange?

Answer 43

The respiratory system allows for humans to oxygenate blood. This happens when alveoli which is the site of gas exchange and surrounded by capillaries turns oxygen-poor blood into oxygen-rich blood.

Question 44

What is endocrine signaling?

Answer 44

It is a slow response that usues signaling mollecules (hormones) secreted from the endocrine cells to act on target cells in distant parts of the body.

Question 45

What are the three types of hormones?

Answer 45

Peptide hormones- soluble in water (not in fat) and cannot diffuse across plasma membrane. ex: insulin or oxytocin Amine hormones - some are soluble in water (attach to target cells to do action), cannot diffuse across a plasma membrane. Ex: melatonin, epinephrine Steroid hormone - insoluble in water (goes through membrane and acts inside), diffused across a plasma membrane. Ex: estrogen, testosterone.

Question 46

How does the endocrine system interact with the nervous system to maintain homeostasis?

Answer 46

it uses the hypothalamus to send signals to the pituitary gland. Hypothalamus - receives information from nerves throughout the body, and intergrates nervous and endocrine systems. Pituitary gland - secretes hormones into the bloodstream to maintain homeostasis.

Question 47

What are the similarities and differences between the endocrine and nervous systems?

Answer 47

endocrine - slower, uses hormones to send messages, organs are calld glands, hormones travel through blood stream nervous - fast, uses action potentials to send messages, organs are brain, spinal cord, and nerves, uses neurons both - react to stimuli, maintain homeostasis, both send messages, hypothalamus is the link between the two systems.

Question 48

What are the main components of our nervous system?

Answer 48

central nervous system - a building block which includes the brain and the spinal cord. This is where the analysis of information occurs peripheral nervous system includes various types of neurons outside of the CNS

Question 49

What are neurons?

Answer 49

dendrites - receive electrical signals from other neurons synaptic terminals - transmit signals from other neurons neurotransmitters - chemical messengers that send signal from the nerve cell ti the target cell cell body- the center for information axons - transmit electrical signals to other neurons

Question 50

What are the three types of neurons?

Answer 50

motor neurons - carry information out the CNS to other neurons to tell the muscles and glands what to do interneurons process information and form local circuits that connect neurons to the brain to integrate sensory information and are only found in the CNS sensory neurons - bring information about what's going on inside and outside the body to the CNS

Question 51

How do electrical signals (action potentials) travel across neurons?

Answer 51

info gets received at the dendrite and travels through the axon until it reaches the axon terminal, and an action potential (electrical signals) gets sent out.

Question 52

What is resting membrane potential?

Answer 52

it is -70 mV, while the inside of the cell is negatively charged compared to the outside. There are lots of K+ inside the cell and lots of Na+ outside the cell

Question 53

What are the differences between graded potentials and action potentials?

Answer 53

graded potentials - electrical signals where the magnitude of the signal varies with the strength of the stimulus. action potentials - are electrical signals where the magnitude of the signal is independent of the strength of the magnitude, and once the membrane potential passes the -55 mV (influx of K+) threshold, an action potential occurs.

Question 54

How do ions move across the cell membrane at each stage of an action potential?

Answer 54

resting potential - there is no movement of ions depolarization - the membrane is positively charged and the Na+ ion gate opens leading to an influx of Na+ repolarization - the membrane goes from positive to negative quickly while the K+ leaves. After this, both the K+ and Na+ ion gates open to return to the resting state.

Question 55

How do action potentials move down the axon?

Answer 55

it starts at the dendrites and Na flows into the cell and K+ moves out of the cells until the action potential reaches the end of the axon. It moves like a wave.

Question 56

What is sensory transduction?

Answer 56

occurs when a stimulus causes the ion channels to open or close in the sensory neuron (receptor potential, not action), which results in a change in membrane potential)

Question 57

What are the “steps” involved in the sensory pathways

Answer 57

1. stimulus 2. sensory detection - response 3. sensory transduction - ion channels open/close creating a receptor or graded potential 4. neurotransmitters release - sends information 5. action potential - depolarization passes and sends information to neuron 6. perception of stimulus by the brain - action potential gets processed in the CNS

Question 58

What are the types of sensory receptors?

Answer 58

thermoreceptors - detect temperature pain receptors - detect harmful conditions chemoreceptors - detect the chemical environment mechanoreceptors - detect pressure, touch, stretch, motion, and sound

Question 59

How do our ears enable us to hear?

Answer 59

Vibrations of hair cells in the Organ of Corti trigger the release of neurotransmitters to the sensory neuron. This hair then moves back and forth depending on the sound. Sensory neurons trigger action potentials to send information to the brain.

Question 60

How is sound received in the inner ear?

Answer 60

Ca+ and Na+ tush in while hair moves back and forth (depolarization) and neurotransmitters release from the hair (action potential)

Question 61

How do hair cells initiate action potentials?

Answer 61

when more neurotransmitters are sent to the sensory neuron, the more action potential and vice versa

Question 62

What is the structure of muscle tissue?

Answer 62

myofibrils - muscle fibers that surround the nuclei and consist of thick and thin filaments sarcomeres - the smallest unit of contraction in a muscle, made of thick and thin filaments. myosin/actin-myosin (thick filament) and actin (thin filaments) are proteins responsible for muscle contractions sliding filament model - consists of myosin and actin interacting to cause muscle contractions

Question 63

How do we depolarize muscle cells?

Answer 63

ACh gets released into the motor neuron and travels to the T-tube causing Ca+ to enter cytosol. Once the muscle contracts Ca+ returns.

Question 64

What is the role of calcium in muscle contractions?

Answer 64

Ca2+ binds to troponin (the key) and moves the tropomyosin (the lock) and exposed the myosin-binding sites on actin.

Question 65

How does the sliding filament model explain the process of muscle contraction?

Answer 65

The slide filament model is when calcium unlocks tropomyosin. This allows for myosin to attach to actin. Myosin then pulls onto actin, which makes the muscle shorter and more flexible. The Ca+ unattaches from the tropomyosin, and the muscle relaxes.