Part 2 — Answer key

Compare your answers after you have finished Part 1.

1. When you gently rinse soil off a seedling, the tiny fuzzy threads on the roots do most of the water and mineral absorbing. What are they called?
   Root hairs
2. In sunlight, photosynthesis uses carbon dioxide and releases oxygen.
   True
3. Those green cell parts that act like mini solar panels, capturing light for photosynthesis, are called what?
   Chloroplasts
4. All plants make flowers at some point in their life cycle.
   False
5. Which plant is a gymnosperm, meaning it makes seeds but no true flowers or fruits?
   Pine
6. A tomato is a botanical fruit because it develops from a flower’s ovary and contains seeds.
   True
7. In a tall tree, which tissue is mainly responsible for moving water and dissolved minerals upward from roots to leaves?
   Xylem
8. After a sunny day, a plant has made lots of sugar in its leaves. Which tissue moves those sugars to roots and developing fruits?
   Phloem
9. Ferns reproduce by making seeds.
   False
10. Pollination is best described as which event?
    Pollen reaching the stigma of a flower
11. What structure directly opens and closes to control a stomata’s opening size?
    Guard cells
12. All cacti are desert plants adapted only to very dry climates.
    False
13. In a typical flower, which part becomes the fruit after fertilization?
    Ovary
14. The light-dependent reactions of photosynthesis occur in the stroma of the chloroplast.
    False
15. Your spinach looks fine at first, then older leaves turn uniformly yellow while new leaves stay relatively greener. Which nutrient deficiency best fits that pattern?
    Nitrogen
16. In most vascular plants, transpiration from leaves helps pull water upward through xylem.
    True
17. You place a celery stalk in a glass of water dyed blue, and the blue lines climb upward within hours. Which tissue is the dye traveling through?
    Xylem
18. Where in the chloroplast does the Calvin cycle (carbon fixation) take place?
    Stroma
19. A potato tuber is a modified stem, which is why it has “eyes” that can sprout.
    True
20. You notice brownish dots under a fern frond, and each dot releases a dustlike cloud when disturbed. Those dots are most closely associated with making what?
    Spores
21. Gymnosperms can produce pollen, but they do not produce fruits.
    True
22. All plants that reproduce by spores lack vascular tissue.
    False
23. A houseplant closes its stomata during a heat wave to conserve water. What is the most immediate effect inside the leaf?
    CO2 levels drop, slowing sugar production
24. In many sun-loving leaves, which tissue is packed with chloroplasts and does a large share of the photosynthesis?
    Palisade mesophyll
25. In alternation of generations, the sporophyte produces spores by meiosis.
    True
26. When you eat broccoli, you are mostly eating which plant structure?
    Unopened flower buds
27. The main water-conducting cells in xylem (vessel elements and tracheids) are usually alive at maturity.
    False
28. An orchid is growing on a tree branch in a rainy forest, with roots exposed to air rather than buried in soil. What term best describes this lifestyle?
    Epiphytic
29. A grass growing in intense sun and heat has “Kranz anatomy” and first fixes CO2 into a four-carbon compound. Which pathway is it using?
    C4
30. A weirdly elegant angiosperm trick is “double fertilization.” What two products does it create?
    A zygote and endosperm
31. You find a plant with parallel leaf veins, scattered vascular bundles in the stem, and flower parts in multiples of three. It is most likely a what?
    Monocot
32. A gardener wants a tree trunk to thicken over years, not just grow taller. Which tissue produces the new xylem and phloem that make woody stems wider?
    Vascular cambium
33. A plant thriving in poor soil is found to have mycorrhizal fungi on its roots. What is the most direct benefit the plant typically gets from this partnership?
    Improved water and mineral uptake, especially phosphorus
34. Strawberries are famous for being “berries,” but botanically the red fleshy part is not the true fruit. What are the true fruits on a strawberry?
    The tiny seed-like dots on the surface
35. A succulent keeps its stomata closed during scorching days and opens them at a cooler time to reduce water loss. When do CAM plants typically open their stomata?
    At night
36. A C3 crop is wilting in hot, dry air, and its stomata are mostly closed. Which internal leaf condition most strongly pushes Rubisco toward photorespiration?
    High O2 relative to CO2
37. In seed plants like pines and sunflowers, which generation is the big, long-lived plant you recognize at a glance?
    Sporophyte
38. A wild plant has pea-like flowers and produces seeds in pods, and you notice knobby root nodules linked to nitrogen-fixing bacteria. Which plant family best fits these clues?
    Fabaceae