Bisc 101: Final Review

Front 1

Explain the process of counter-current exchange in fishes.

Back 1

Water and blood flow in opposite directions within the fishes gills because of this the partial pressure of oxygen within the water is always higher than the partial pressure within the capillaries in the secondary lamellae. This helps to maintain the concentration gradient and maximize the removal of oxygen since gases will move from an area of high pressure to an area of low pressure.

Front 2

Explain the process of negative feedback. Give an example.

Back 2

A stimulus which causes a change in the set point of a condition in the body is detected. Mechanisms in the body corrects the change back to the set point. Body senses that the set point is reached and turns off the correction mechanism. Example: The regulation of blood glucose levels.

Front 3

Why do animals need to eat? (Hint: bio-energetics)

Back 3

- Animals use chemical energy from food
- ATP produced by cellular respiration is used for cellular work, growth, biosynthesis, repair
- All process are inefficient: ~60% of total energy in any food is converted to ATP and 40% is lost as heat

Front 4

Explain what is happening in this graph.

Back 4

Bohr Shift/Right Shift: At lower (blood) pH values (due to an increase in activity) the ability for oxygen to bind to hemoglobin decreases (the partial pressure stays the same) and promotes an increase in the release of oxygen. The oxygen association-disassociation curve will shift to the right.

Front 5

Explain the process of homeostasis in humans with regards to temperature. (Fill in the blanks)

Back 5

A: Thermostat in hypothalamus activates cooling mechanisms.
B: Sweat glands secrete sweat that evaporates, cooling the body.
C: Blood vessels in skin dilate; capillaries fill with warm blood; heat radiates from skin surface
D: Increased body temperature (such as when exercising or in hot surroundings)
E: Body temperature decreases; thermostat shuts off cooling mechanisms
F: Homeostasis; internal body temperature of approximately 36-38 C
G: Body temperature increases; thermostat shuts off warning mechanisms
H: Decreased body temperature (such as when in cold surroundings)
I: Blood vessels in skin constrict, diverting blood from skin to deeper tissues and reducing heat loss from skin surface.
K: Thermostat in hypothalamus activates warning mechanisms
J: Skeletal muscles rapidly contract, causing shivering, which generates heat.

Front 6

What are two thermoregulatory mechanisms initiated by the hypothalamus?

Back 6

1) Heat conserving (ex. vasoconstriction, piloerection, shivering and nonshivering thermogenesis)
2) Heat releasing (ex. vasodilation and sweating)

Front 7

Describe the odd coincidence that relates Basal Metabolic Rate to climbing Mt.Everest.

Back 7

The partial pressure of oxygen at the top of Mt. Everest is equal to the minimum requirements to satisfy basal metabolic rates for humans.

Front 8

Define torpor.

Back 8

Decreasing metabolic rate and temperature to conserve energy generally in times of low food availability. Torpor can be daily where the animal has normal body temperature and metabolism during the day and have it decreasing during the night.

Front 9

Define hibernation. Give an example of an animal that practices hibernation.

Back 9

Long bouts of torpor during the winter to conserve energy that would otherwise be used to deal with low temperatures. Example: Chipmunks, squirrels, bats, skunks (NOT BEARS)

Front 10

Define Aestivation

Back 10

Long bouts of torpor during the summer to conserve energy that would be used to deal with high temperatures and generally dry environments

Front 11

Define winter sleep.

Back 11

Reduction of activity in the winter to save energy, body temperature and metabolism remain relatively the same as normal, but heart rate is reduced

Front 12

Define carnivore lethargy

Back 12

Reduction of activity to save energy, body temperature and metabolism remain relatively the same as normal, but heart rate is reduced. (Essentially winter sleep but not necessarily for the winter)

Front 13

Explain the process of blood glucose regulation. (Fill in the blanks)

Back 13

A: Body cells take up more glucose
B: Insulin
C: Beta cells of pancreas release insulin into the blood
D: Liver takes up glucose and stores it as glycogen
E: Blood glucose levels decline.
F: Stimulus; blood glucose level rises
G: Homeostasis; blood glucose level about 90mg/100mL
H: Blood glucose level rises
I: Stimulus: Blood glucose level falls
J: Alpha cells of pancreas release glucagon
K: Liver breaks down glycogen and releases glucose
L: Glucagon

Front 14

Define homeostasis. Provide an example of an animal that practices homeostasis.

Back 14

Maintenance of a constant internal environment. (Depends on negative-feedback control loops) Example: Humans, arctic fox (with regards to temperature)

Front 15

Define enantiostasis. Provide an example

Back 15

Internal environments fluctuate with external changes. Example: largemouth bass with regards to temperature (Conformers)

Front 16

Explain the relationship between blood flow, pressure, speed, and surface area.

Back 16

Cross-sectional area of all the capillaries total is larger than the area of arteries and veins. Velocity at the arteries is higher because of the heart pumping; at the capillaries velocity decreases due to the smaller size and to allow for diffusion into cells; at the veins velocity increases due to the decrease in cross-sectional area. Blood pressure is highest at the arteries because of the heart pumping (blood pressure decreases the farther away from the heart you are); at the capillaries blood pressure is low (capillaries are thin and would break at high pressure); at the veins there is very little blood pressure

Front 17

Define basal metabolic rate.

Back 17

Minimum metabolic rate of a non-growing endotherm, at rest, with an empty stomach and no stress.

Front 18

Explain the mechanism involved in muscle contraction (starting with signal from nervous system)

Back 18

1) Neurotransmitter diffuses across the synaptic cleft and attaches to receptors; Release of calcium
2) Calcium binds to troponin which causes a conformational change that moves tropomyosin away from cross-bridge binding sites
3) Myosin head binds to actin filament when ATP is split
4) When ADP and Pi (organic phosphate) is released from the myosin head, it causes the myosin head to slide (which is the muscle contraction)
5) When new ATP attatches to the myosin head it detaches from the cross bridge)

Front 19

Provide an explanation for the differences of these two graphs.

Back 19

Smaller endotherms need less oxygen compared to large endotherms (less tissue means lower amount of oxygen needed) however smaller endotherms are generally more active and alert, as well as a surface area to volume ratio leads to an increase in metabolic rates. (Uses more oxygen per kg of tissue)

Front 20

Compare the structures of the circulatory systems in fish, amphibians, reptiles (except birds) and mammals.

Back 20

Fish: 2 chambered heart (single atrium and ventricle); blood flows from heart to gills; oxygenated blood is sent to organs and tissues
Amphibian: 3 chambered heart ( one ventricle and two atria); blood sent to the lungs for oxygenation and returns to the heart before being pumped to the rest of body
Reptile: 3 chambered heart (one ventricle and 2 atria); blood sent to the lungs and returns to the heart before being pumped to the rest of the body; varying degrees of separation between the left and right sides of the ventricle
Mammals: 4 chambered heart (2 ventricles and 2 atria); complete separation of ventricles; double circulation separates deoxygenated blood from oxygenated

Front 21

Define snare proteins.

Back 21

Proteins that surround vesicles holding neurotransmitters. (Ca2+ binds to proteins causing a structural change to squeeze the vesicle causing it to release neurotransmitters)

Front 22

How do plant cells differ from animal cells?

Back 22

Plants have chloroplasts, cell walls and larger vacuoles

Front 23

List all the differences between monocot and dicot plants

Back 23

Monocot: leaves have parallel veins; one cotyledon; have fibrous root system; floral parts are in multiples of three; vascular roots have large vascular cylinder with central pith; stems have vascular bundles distributed randomly in pith tissue

Dicots: leaves have net-like veins; two cotyledon; roots are a taproot system; floral parts are in parts of 4-5; xylem in the root are in the shape of a cross; vascular bundles arranged in a circle around a central pith; cambium present between xylem and phloem

Front 24

Define perennial plant. Give an example.

Back 24

A plant that grow for many years. Example: trees, lawn grass, bushes, shrubs etc.

Front 25

Define angiosperm. Give an example.

Back 25

Flowering plants (broken down to two monocot & dicot) Example: any flowering plant, roses, daises etc.

Front 26

Define gymnosperms.

Back 26

Conifers. Example: evergreen trees

Front 27

Define meristematic tissues. Give an example.

Back 27

Part of plant that is actively dividing responsible for primary growth. Example: apical bud and root tips

Front 28

Describe the process of water movement up a plant.

Back 28

Stomata opens due to increase in light (water, low CO2 etc.) and water is loss through the leaves in a process called transpiration. Water leaving the leaves creates a water deficit (negative tension). This creates a negative pressure (suction force) and causes a transpirational pull of water up into the xylem. Water forms a column due to hydrogen bonding (bulk flow of water).

Front 29

What are the factors that open/close the stomata?

Back 29

Open: when there is a lot of light, lot of water, high [K+], low CO2
Close: when there is low light, low water and low [K+]

Front 30

Define transpiration.

Back 30

Water loss through the leaves.

Front 31

Describe the movement in the phloem.

Back 31

Sugars are moved from the leaves to the roots and other parts of the plant. Movement of sugars is active transport; uses proton pumps (requires ATP). At the leaves there is a build up of sucrose, water enters the phloem (due to concentration gradient) and creates a positive pressure which forces sucrose down the plant and to areas where it is needed.

Front 32

Explain the electron transfer chain.

Back 32

- Electrons carried by NADH and FADH2 enter electron transport chain and are passed along through a series of carrier proteins, each transfer causes the electrons to lose a little bit of energy
- Energy from the movement of electrons lead to the transport of protons out across the inner mitochondrial membrane creating a proton gradient
- Oxygen is the last electron acceptor in the chain to allow for more electrons to enter the chain, if oxygen is absent, the chain is stalled as there is nowhere for the electrons to go

Front 33

Define catabolism.

Back 33

Type of metabolism where complex molecules are broken down into simpler ones (ie. cellular respiration; cells produce energy)

Front 34

Define anabolism.

Back 34

Type of metabolism where simpler molecules are built up into complex molecules. (Cells require energy)

Front 35

What is the NET gain of energy from glycolysis

Back 35

2 ATP, 2 NADH

Front 36

Where is energy being produced in the citric acid cycle? (From which step)

Back 36

- NADH is produced at isocitrate going to alpha-ketoglutarate; and from ketoglutarate going to succinyl co-a; and malate to oxylate

- ATP is produced from succinyl co-a to succinate

- FADH2 is produced from succinate to fumarate

Front 37

How much energy is being produced from cellular respiration?

Back 37

38 total from glycolysis, citric acid, and acetly co-a production; 3(10 NADH) + 2(FADH2) + 4 ATP; NADH = 3 ATP; FADH2 = 2 ATP

Front 38

How much ATP is produced from the citric acid cycle?

Back 38

From succinyl Co-A to succinate

Front 39

Define proton motive force (PMF)

Back 39

Drives hydrogen ions into ATP synthase in a process called chemiosmosis. Occurs in photosynthesis and cellular respiration.

Front 40

Define chemiosmosis.

Back 40

Electron transported in an electron transport chain ( in the thylakoid membrane; for photosynthesis)

Front 41

Give three examples of macro-nutrients.

Back 41

K, Na, P, Ca, Mg

Front 42

Provide 3 examples of micro-nutrients.

Back 42

Fe, B, Mn, Zn, Cu

Front 43

Describe the process of double fertilization.

Back 43

Two sperms enter the pollen tube. One pollen

Front 44

Where in the cell does the citric acid cycle take place?

Back 44

(Inner?) Mitochondrial Matrix

Front 45

Where in the citric acid cycle is FADH2 produced.

Back 45

Between the production of succinate to fumarate; FAD to FADH2

Front 46

Define parthenocarpy

Back 46

Development of fruit without fertilization

Front 47

Define pleiotropy. Provide an example.

Back 47

The same hormone can activate different receptors and produce different responses. Or the same hormone can induce different effects on the same type of receptor.
Example: Epinephrine; Attached to a beta receptor in the liver will cause the breakdown of glycogen and release glucose; In blood vessels, beta receptors will cause vessels to dilate, and alpha receptors to constrict.

Front 48

How do seeds know when to germinate?

Back 48

- Temperature increases
- more moisture available
- levels of gibberellic acid increases (activity of alpha amylase goes up and sugar is produced)
- endosperm breaks down and plants gets energy to grow

Front 49

Define monoecious. Give an example.

Back 49

Type of cross-pollination. Pollen from a different plant will fertilize the ovule. (Male and female parts of a flower are separated on the same plant) Example: corn

Front 50

Define diecious

Back 50

Type of cross-pollination. Male and female flowers are on different plants. Examples: fig trees