quizzes form Exam 3

Question 1

If photosynthesizing green algae are provided with CO2 synthesized with heavy oxygen (18O), later analysis will show that all but one of the following compounds produced by the algae contain the 18O label. That one is

Answer 1

O2

Question 2

Where does the Calvin cycle take place?

Answer 2

stroma of the chloroplast

Question 3

What does the chemiosmotic process in chloroplasts involve?

Answer 3

establishment of a proton gradient across the thylakoid membrane

Question 4

In a plant cell, where are the ATP synthase complexes located?

Answer 4

thylakoid membrane and inner mitochondrial membrane

Question 5

Which statement describes the functioning of photosystem II?

Answer 5

The electron vacancies in P680+ are filled by electrons derived from water.

Question 6

As a research scientist, you measure the amount of ATP and NADPH consumed by the Calvin cycle in 1 hour. You find 30,000 molecules of ATP consumed, but only 20,000 molecules of NADPH. Where did the extra ATP molecules come from?

Answer 6

cyclic electron flow

Question 7

Assume a thylakoid is somehow punctured so that the interior of the thylakoid is no longer separated from the stroma. This damage will have the most direct effect on which of the following processes?

Answer 7

the synthesis of ATP

Question 8

In mitochondria, the ETC translocates protons from the matrix into the intermembrane space, whereas in chloroplasts, the ETC translocates protons from

Answer 8

the stroma to the thylakoid space.

Question 9

P680+ is said to be the strongest biological oxidizing agent. Why?

Answer 9

This molecule has a stronger attraction for electrons than oxygen, to obtain electrons from water.

Question 10

A flask containing photosynthetic green algae and a control flask containing water with no algae are both placed under a bank of lights, which are set to cycle between 12 hours of light and 12 hours of dark. The dissolved oxygen concentrations in both flasks are monitored. Predict what the relative dissolved oxygen concentrations will be in the flask with algae compared to the control flask.

Answer 10

The dissolved oxygen in the flask with algae will be higher in the light, but lower in the dark.

Question 11

In the human species, all somatic cells have 46 chromosomes. Which of the following can also be true?

Answer 11

A plant species (privet shrubs) has 46 chromosomes per cell

Question 12

Which of the following is a true statement about sexual vs. asexual reproduction?

Answer 12

In sexual reproduction, individuals transmit 50% of their genes to each of their offspring.

Question 13

A triploid cell contains three sets of chromosomes. If a cell of a usually diploid species with 42 chromosomes per cell is triploid, this cell would be expected to have which of the following?

Answer 13

63 chromosomes in 21 sets of 3

Question 14

In a human karyotype, chromosomes are arranged in 23 pairs. If we choose one of these pairs, such as pair 14, which of the following do the two chromosomes of the pair have in common?

Answer 14

Length, centromere position, staining pattern, and traits coded for by their genes

Question 15

The centromere is a region in which

Answer 15

chromatids remain attached to one another until anaphase

Question 16

Taxol is an anticancer drug extracted from the Pacific yew tree. In animal cells, Taxol disrupts microtubule formation by binding to microtubules and accelerating their assembly from the protein precursor, tubulin. Surprisingly, this stops mitosis. Specifically, Taxol must affect

Answer 16

the formation of the mitotic spindle.

Question 17

In the cells of some organisms, mitosis occurs without cytokinesis. This will result in

Answer 17

cells with more than one nucleus.

Question 18

Which statement below best describes the properties of oncogenes and tumor suppressors?

Answer 18

Oncogenes code for proteins that are positive regulators of the cell cycle. Tumor suppressors are negative regulators of the cell cycle.