18.7–18.12: Pollination, fertilization, and seed dispersal often depend on help from other organisms.
Because sexual reproduction requires two individuals, one plant must get its gametes to join with those of another. A broad array of solutions to this problem has evolved.
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Question 18.28
When, after seed germination, does photosynthesis begin?
- a) when the seed coat breaks open
- b) when the first stem is formed
- c) when the shoot emerges from the soil
- d) the second the seed begins to germinate
- e) when the root is formed
Question 18.29
The seed of a certain plant remains dormant until it is exposed to fire. What would be the greatest advantage of this for the survival of this plant species?
- a) avoiding germination during cold winters
- b) germination under ideal soil conditions
- c) avoiding competition with other plants
- d) germination timed to coincide with autumn
- e) utilization of heat energy to break down starch to glucose to feed the embryo
Question 18.30
The scientific term for wood is:
- a) primar y phloem.
- b) cork.
- c) secondar y xylem.
- d) epidermis.
- e) pith.
Question 18.31
When you are seven years old, you scratch your name 4 feet above the ground into a 12-
- a) 16 feet
- b) 4 feet
- c) 8 feet
- d) 12 feet
- e) 2 feet
