Question

Which of the following statements about active exclusion of sodium are true?

	a.	It is dependent on a proton gradient and ATP
	b.	It requires antiporters that exchange H+ for Na+
	c.	It prevents accumulation of sodium in plant cells
	d.	It allows for greater uptake of sodium into plant cells
	e.	All of the above statements are true EXCEPT D

Double fertilization refers to:

	a.	Cross-pollination by two distinct mechanisms (e.g. wind and bees)
	b.	The formation of male (n) and female (n) gametes
	c.	The development of a fruit in an angiosperm
	d.	The process of embryogenesis and seed maturation
	e.	The formation of a zygote (2n) and primary endosperm nucleus (3n)

One important difference between the anatomy of roots and the anatomy of leaves is that _____.

	a.	Leaves are covered in a waxy cuticle and stomata, which is absent from roots
	b.	Only roots have ground tissue
	c.	Only leaves have epidermal tissue
	d.	Root cells have cell walls and leaf cells do not
	e.	Roots contain vascular tissue, whereas leaves do not

Which of the following statements regarding ATP is true?

	a.	It has high potential energy because it is reduced.
	b.	It provides energy coupling between exergonic and endergonic reactions.
	c.	It is a highly stable storage form of energy in cells.
	d.	It is not able to regulate enzyme activity.
	e.	All of the above.

You consume a large meal rich in carbohydrates and protein. Cellular concentrations of acetyl-CoA and NADH increase significantly. What will happen as a result?  

	a.	The rate of the citric acid cycle will increase
	b.	Excess acetyl-CoA will be used to make glucose for storage as glycogen
	c.	Excess acetyl-CoA will be used to synthesize fatty acids for storage in adipose (fat) tissue
	d.	Excess acetyl-CoA will be used to synthesize new amino acids and proteins
	e.	All of the above

You expose a plant that contains chlorophyll a, chlorophyll b, and carotenoids to different wavelengths of light, then measure the level of resonance-energy transfer. Which of the following results would you expect?

	a.	Oxygen production is highest upon exposure to yellow light
	b.	Oxygen production is highest upon exposure to blue light
	c.	Oxygen production is highest upon exposure to white light
	d.	Oxygen production is highest upon exposure to green light
	e.	Oxygen production is highest upon exposure to far red light

High levels of ATP will impact cellular respiration by:

	a.	Decreasing rates of pyruvate processing to acetyl-CoA
	b.	Increasing rates of glycolysis and the citric acid cycle by allosteric activation of enzymes
	c.	Decreasing rates of glycolysis and the citric acid cycle by competitive inhibition of enzymes
	d.	Decreasing rates of glycolysis and the citric acid cycle by allosteric inhibition of enzymes
	e.	ATP levels do not impact the rates of cellular respiration pathways

When consumed, fatty acids provide more calories per gram than carbohydrates because:

	a.	Fatty acids have a greater number of C-O bonds, where electrons are NOT shared equally
	b.	Fatty acids are the most important form of chemical energy for all organisms
	c.	Fatty acids have a greater number of C-O bonds, where electrons are shared more equally
	d.	Fatty acids have a greater number of C-C and C-H bonds, where electrons are shared more equally
	e.	Fatty acids are smaller molecules

You isolate an enzyme from the human stomach to test its activity. In order to measure optimal enzyme function, which of the following laboratory conditions should you use in the experimental reactions?

	a.	Solutions with a pH ~2
	b.	Reaction temperature close to normal body temperature (98.6°F)
	c.	Include substrates for which the enzyme has high affinity
	d.	Include high concentrations of substrate
	e.	All of the above

In glycolysis, glucose-6-phosphate (G-6-P) is converted to fructose-6-phosphate (F-6-P). Which of the following statements about this reaction is true?

	a.	G-6-P is a hexose, whereas F-6-P is a pentose
	b.	ATP is spent to form F-6-P
	c.	ATP is generated in the formation of F-6-P
	d.	A 5-point monosaccharide ring structure is formed, allowing for the addition of a second phosphate group in the subsequent step
	e.	All of the above are correct

You are conducting a plant growth experiment in a research laboratory. Prior to setting up your experiment, you notice that ~25% of the seed coats appear damaged. You plant them anyway, but notice that ~25% of your plants fail to germinate. All of the plants have been watered regularly, and have received adequate light. What is the most likely cause of the lack of germination?

	a.	The hypocotyls were damaged
	b.	The cotyledons were damaged
	c.	The radicles were damaged
	d.	A mutation that interfered with asexual reproduction
	e.	All of the above likely occurred

In humans, fermentation results in the formation of ________, whereas fermentation in yeast results in the formation of _________. In humans, this pathway occurs when ________ is absent.

	a.	Lactate; glucose; ATP
	b.	Lactate; ethanol; oxygen
	c.	Citrate; glucose; ATP
	d.	Pyruvate; ethanol; NAD+
	e.	Ethanol; lactate; oxygen

Which of the following statements regarding the Calvin Cycle are correct?

	a.	The rate will be increased by a loss-of-function mutation in rubisco
	b.	The rate will be increased by having NADP+ available only in its oxidized form (rather than its reduced form)
	c.	It is an endergonic process
	d.	It occurs during the night time in most plants
	e.	All of the above are correct

All of the following statements regarding structural polysaccharides are true, EXCEPT:

	a.	They form parallel strands that are joined together by peptide or hydrogen bonds
	b.	Structural polysaccharides include cellulose, chitin, and peptidoglycan
	c.	They are comprised of β-glucose molecules
	d.	They can be found in the cell walls of plants and external skeletons of insects
	e.	They can easily be broken down by phosphorylase

Answer 1

1- ALL OF THE FOLLOWING ARE TRUE

sodium ions can not enter the cell directly so they need help of proteins or other system to import. the antiport system occurs when ions enter and h+ goes out of the cell. the ports donot work when enough ions have been accumulated. thus all options are correct

2- ANSWER IS-The formation of a zygote (2n) and primary endosperm nucleus (3n)

it is called double fertilization because fertilization occurs with two cells to form endosperm nucleus which is 3n. this is because two small nuclei are present at center

3- ANSWER IS-Leaves are covered in a waxy cuticle and stomata, which is absent from roots

roots have root hair which enables them to take water from the roots. whereas the stem donot need root hairs as they get water through xylem and have stomata for exchange of gases

4- ANSWER IS- all of the above

ATP has high G value which is due to the phosphoryl group and because of this high value it is able to couple exergonic and endergonic reactions.ithas high stability thus used as an energy source

5- ANSWER IS - ALL OF THE ABOVE

the reason is excess is used for storage for the use in starvation conditions and enters kreb cycle for oxidation and energy sources.

6- ANSWER IS - oxygen production is highest upon exposure to far light

tis is because carotenoids work most at red light due to which photosynthesis process is effeciently done.

7- ANSWER- Decreasing rates of pyruvate processing to acetyl-CoA

competitive inhibition doesnot occur because the enzymes have different affinity. the gycolysis rate is decreased but not by competitive inhibitin which results in not entering the kreb cycle

8- ANSWER-Fatty acids have a greater number of C-C and C-H bonds, where electrons are shared more equally

because of this bond energy required is less thus atp invested are low and net energy increases

9- ANSWER- all of the above

the ph is low because in stomach the ph is reduced because of presence of hydrochloric acid and high substrare is required so that enzyme can act efficiently'

10- ANSWER-G-6-P is a hexose, whereas F-6-P is a pentose

the fructose is 5- membered ring whereas hexose is 6 membered ring

11- ANSWER - ALL OF THEM CAN OCCUR

this is because the cotyleedons , radicals can differ due to genetic variance and equal chances of mutations are there. thus any can occur

12- ANSWER- OPTION B LACTATE, ETHANOL AND OXYGEN

13- ANSWER-The rate will be increased by having NADP+ available only in its oxidized form (rather than its reduced form

14- ANSWER-They are comprised of β-glucose molecules

glucose molecules are less likely not present they form large complexes thus cannot form as component of polysaccharide