Answers sample questions week 7 and 8-1 PDF

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Sample'questions'week'7/'8'(plant'structure,'transport,'development'and'signalling)' ' 1) Unripe fruits protect seeds from predation and early germination. What is the major function of ripe fruits? A) attracting pollinators B) dispersing seed C) deterring predators D) keeping the seed hydrated before germination ' 2) When an animal cell is placed in a hypotonic solution and water enters the cell via osmosis, the volume of the cell increases until it bursts. This does not happen to plant cells, because A) they have large central vacuoles, which provide abundant space for storage of incoming water. B) the composition of their plasma membranes differs from that of animal-cell plasma membranes in a way that provides much greater strength. C) they have cell walls, which prevent the entry of water by osmosis. D) they have cell walls, which provide pressure to counteract the pressure of the incoming water. E) certain proteins embedded in their plasma membranes act as "check valves," releasing excess water before it can cause the cell to burst. 3) Water potential in plants consists mainly of ☐ solute potential and osmotic potential. ☐ solute potential and membrane potential. ☐ pressure potential and solute potential. ☐ pressure potential and membrane potential. ☐ solute potential only.

(check one box)

4) A summer occupation in the Corn Belt states is de-tasseling the corn: removing unwanted male flowers so that female flowers on the same plant are pollinated by the desired pollen for the hybrid corn. What does this tell you about corn? (check one) ☐ The flowers are perfect and the plant is dioecious. ☐ The flowers are perfect and the plant is monoecious. ☐ The flowers are imperfect and the plant is dioecious. ☐ The flowers are imperfect and the plant is monoecious. 5) During self-fertilization, which of the following is absent? (check all relevant boxes) ☐ pollination ☐ transfer of pollen from one plant to the other ☐ transfer of pollen from anther to stigma ☐ formation of gametes ☐ genetically diverse offspring

6) You buy some fresh fruit at the grocery store. When you get home, you are in a hurry, and you put the fresh fruit in the crisper with some overripe fruit. At the end of the week you are disappointed to find that your new fruit has already become overripe. What happened? A) The refrigerator was probably set too high. As a result, the production of auxin was induced in overripe fruit and caused production of ethylene in the fresh fruit. B) The fresh fruit was not washed before refrigerating, so ethylene was still present on the surface of the fruit, causing the fresh fruit to overripe. C) The overripe fruit released ethylene that increased the rate of ripening in the fresh fruit. D) The fresh fruit was damaged, producing ethylene that sped up the ripening process. 7) An eccentric millionaire botanist has offered a $25,000 scholarship to anyone who can successfully get a plant to grow through a vertical maze in complete darkness. The maze is not in a box; the maze is simply drawn on the wall, and the contestants must get their plant to grow in a pattern that matches the path through the maze. You need the money and feel confident that you can accomplish this task. Which of the following techniques will help you succeed? A) Apply auxin directly to the shoot tip on the side to which you want the tip to bend. B) Apply auxin directly to the lower part of the stem opposite from the direction you want the stem to bend. C) Inject compounds that block auxin receptors into the part of the stem opposite from the direction you want the stem to bend. D) Plant the roots in two different pots, and apply auxin to the root bucket that is on the same side as the direction you want the plant to bend. 8) What is the right sequence of steps during infection of plants by nitrogen-fixing bacteria? _B_ _ A __ _ C _ _ D _ _ E _ A) Rhizobia release Nod factors; B) roots release flavonoids; C) rhizobia proliferate inside of root hair; D) infection thread grows into the root cortex; E) nodule forms. 9) The most effective way to kill a tree is to remove a ring of bark from the circumference. Why does the tree die? The bark contains the phloem of the tree, which is needed to transport sugars and other nutrients from source to sink. Without the bark, no sugars can be transported from the leaves to the roots. 10) Wood is an accumulation of ☐ primary xylem. ☐ secondary xylem. ☐ vascular bundles. ☐ primary phloem. ☐ secondary phloem.

11) Why do plants use cotransporters to transfer anions into cells, but use ion channels to import cations? To move ions into the cell against their concentration gradient, an additional source of energy is needed. Proton pumps establish an electrochemical gradient across the plasma membrane, with high proton concentrations outside of the cell. Thus, the outside of the plasma membrane is positively charged, while the cytosolic side is negatively charged. Cations are attracted by these negative charges, and therefore can pass the ion channel. The negatively charged anions require a different form of energy to drive their movement into the cell: the cotransport of anions with protons that move with their concentration gradient provides this energy. ! 12) Where are the youngest wood and the youngest bark in a tree trunk? A) The youngest wood is in the center of a tree; the youngest bark is the outside of the bark. B) The youngest wood is in the center of a tree; the youngest bark is the inner part, next to the vascular cambium. C) The youngest wood is toward the outside, near the vascular cambium; youngest bark is the outside of the bark. D) The youngest wood is toward the outside, near the vascular cambium; youngest bark is the inner part, next to the vascular cambium. ! 13)'Take'a'look'at'the'figure'shown'below:' a) Suppose you laid a seedling on its side so that the root was parallel to the ground. Immediately after the change in position, where in the root cells (position A, B, or C ) would you find the amyloplasts? b) Suppose you laid a seedling on its side so that the root was parallel to the ground. Several hours after the change in position, where in the root cells (position A, B, or C) would you find the amyloplasts? 14) Angiosperms are unique in having double fertilization that forms endosperm. What is true about double fertilization in angiosperms? A) Two sperm combine with a polar nucleus to form endosperm. B) Two sperm combine with two eggs to form the zygote and endosperm. C) One sperm combines with the polar nuclei to form the zygote, and one sperm combines with the egg to form endosperm. D) One sperm combines with the egg to form the zygote, and one sperm combines with the polar nuclei to form endosperm....