Pollen grains contain:

a. hormones.

b. food for the new plant generation.

c. eggs that will be fertilized by sperm.

d. sperm.

e. chloroplasts.

Phototropism and gravitropism lead to the bending of shoots or roots toward or away from a stimulus (light or gravity, respectively). Such bending is brought about by:

a. increased growth over the general surface of the root or shoot.

b. differential growth on opposite sides of the root or shoot.

c. muscular contractions, leading to a curvature in the root or shoot.

d. loss of water into the atmosphere.

e. all of the above.

Photoperiodism allows some plants to respond to _________ by timing such things as ________ in accordance with the amount of _________ they are exposed to.

a. predators; dormancy; moisture

b. competition; growth; moisture

c. the seasons; growth; toxins

d. other plants; flowering; IAA

e. the seasons; flowering; darkness

In closed circulation systems, blood ____________ blood vessels, while in open circulation systems, it ___________ to bathe surrounding tissues.

Insects and crustaceans have a skeleton different from ours. Theirs is an ____________: a skeleton that forms an ____________ on an animal body.

Animals with an exoskeleton are able to continue to grow by employing the practice of ____________, which can be defined as____________.

With respect to egg fertilization and protection, the primitive, ancestral state in the animal kingdom is believed to be one in which eggs and sperm are _________ into water and brought together by water currents, after which parents provide ________ care to fertilized eggs.

The more complex the animal in the animal kingdom, the ________ the number of eggs that are likely to be produced and the _________ amount of care parents are likely to provide to fertilized eggs.

The amniotic egg, which evolved in ________, was important because it allowed eggs to be laid ________.

Sexual reproduction in animals entails a fusion of ____________ and ____________ from different individuals.

Budding, fission, and parthenogenesis are all forms of _________ practiced by animals. In parthenogenesis, an ____________ develops into an adult organism.