2.  a.  autotrophs.  b.  unicellular.  c.  heterotrophs.  d.  prokaryotes.

3.  a.  oxygen and carbon dioxide.  b.  carbon dioxide and water.  c.  sugar and oxygen.  d.  water and sugar.

4.  a.  sugar and water.  b.  sugar and oxygen.  c.  carbon dioxide and oxygen.  d.  carbon dioxide and water.

5.  a.  water.  b.  chemicals.  c.  oxygen.  d.  the sun.

6.  a.  vascular tissue  b.  zygote  c.  leaf  d.  cuticle

7.  a.  gametes.  b.  chloroplasts.  c.  tissues.  d.  vacuoles.

8.  a.  gametes  b.  gametophyte  c.  sporophyte  d.  zygotes

9.  a.  gametes.  b.  zygotes.  c.  sporophyte stage.  d.  gametophyte stage.

10.  a.  It transports water and food inside the plant.  b.  It supports the plant's stems and leaves.  c.  It positions the plant's leaves closer to the sun.  d.  It transports egg and sperm cells for reproduction.

11.  a.  live in water.  b.  can absorb water from soil.  c.  only live in rainy areas.  d.  contain a lot of minerals.

12.  a.  transportation of water.  b.  absorption of water.  c.  photosynthesis.  d.  reproduction.

13.  a.  moist soil  b.  bogs  c.  rocks by a stream  d.  tree trunks

14.  a.  how they make food.  b.  where they obtain water and nutrients.  c.  how they transport water and nutrients.  d.  how they reproduce.

15.  a.  mosses  b.  liverworts  c.  lichens  d.  hornworts

16.  a.  rhizoid.  b.  stalk.  c.  capsule.  d.  gametophyte.

17.  a.  rhizoid.  b.  stalk.  c.  capsule.  d.  gametophyte.

18.  a.  rhizoid.  b.  sporophyte  c.  capsule.  d.  gametophyte.

19.  a.  gardening  b.  food  c.  fuel  d.  forest regrowth

20.  a.  produces spores and gametes  b.  has a gametophyte and a sporophyte  c.  needs water for reproduction  d.  has vascular tissue

21.  a.  vascular tissue and spores  b.  vascular tissue and seeds  c.  vascular tissue and leaflike structures  d.  vascular tissue and underground stems

22.  a.  ferns and their relatives  b.  partial decomposition of dead plants  c.  a 100-year time span  d.  weight of compressed layers of dead plants

23.  a.  Their leaves are called fronds.  b.  They are vascular plants.  c.  They are seed plants.  d.  They have jointed stems.

24.  a.  roots and fiddleheads  b.  roots and stems  c.  stems and leaves  d.  stems and fronds

25.  a.  leaves.  b.  roots.  c.  stems.  d.  spores.

26.  a.  in fiddleheads.  b.  in an underground stem.  c.  in a new gametophyte.  d.  on the underside of fronds.

27.  a.  to transport spores to new locations  b.  to transport water to all cells  c.  so that egg and sperm cells can join  d.  so that fiddleheads develop for food

28.  a.  wheat  b.  soy beans  c.  rice  d.  corn

29.  a.  hydroponics  b.  tractor  c.  computer  d.  satellite imaging

30.   a.  saves money.  b.  reduces the use of fertilizer.  c.  enables crops to grow in areas with poor soil.  d.  creates insect-resistant crops.

31.   a.  satellite imaging  b.  genetic engineering  c.  hydroponics  d.  precision farming