The text notes that bone density can increase in response to exercise. Imagine two fairly inactive people who decide to start exercising. One becomes a runner while the other becomes a swimmer. Who experiences the greater increase in bone density: the swimmer (in the arm bones) or the runner (in the leg bones)?

The four basic types of tissue in the human body are:

a. epithelial, connective, muscle, nervous.

b. epithelial, blood, muscle, nervous.

c. skin, bone, muscle, nervous.

d. skin, connective, heart, nervous.

e. epithelial, bone, connective, muscle.

Muscle fibers that are striated and voluntary are found in:

a. cardiac muscle.

b. skeletal muscle.

c. smooth muscle.

d. rough muscle.

e. all four types of muscle.

Hormones and the glands or cells that secrete them make up the:

a. cardiovascular system.

b. respiratory system.

c. lymphatic system.

d. urinary system.

e. endocrine system.

Surface epidermal cells of the skin:

a. rapidly divide and are filled mostly with keratin.

b. never divide and remain in place through adult life.

c. rapidly divide and are in place only a short time.

d. are dead and filled with keratin.

e. rapidly divide and are filled with fat.

Cells called _____ build bone tissue, _____ maintain it, and _____ break it down.

a. osteoblasts; osteoclasts; osteocytes

b. osteoclasts; osteons; osteoblasts

c. osteoblasts; osteocytes; osteoclasts

d. osteons; osteocytes; osteoclasts

e. osteocytes; osteoblasts; osteoclasts

The essence of muscle contraction is that thick and thin muscle proteins:

a. slide past each other.

b. link irreversibly with each other.

c. are short enough to respond quickly.

d. stay completely separate.

e. pull in opposite directions.

No skeletal muscle can contract without first:

a. receiving a hormone signal.

b. checking on the status of nearby skeletal muscles.

c. lining up its actin and myosin filaments.

d. receiving a nervous system signal.

e. linking to a bone.

In all angiosperms, a growing embryo is first surrounded by a _______, which will serve to _______ the embryo until it germinates in the ground.

Fruit can be defined as the mature _______ of an angiosperm. Fruit in this sense lies outside the _______ that surrounds the angiosperm embryo.