Pituitary dwarfism may be caused by reduced production of ____.

A) melatonin
B) testosterone
C) calcitonin
D) growth hormone
E) parathyroid hormone

One characteristic that makes Caenorhabditis elegans attractive for developmental studies is:

A) its small, transparent body
B) the extensive number of genes shared with humans
C) the developmental defects that occur in this organism
D) the close evolutionary relationship between this mammal and humans
E) the presence of zygotic segmentation genes, similar to those found in humans

Blood chemistry changes are examples of ________ stimuli, whereas sympathetic nervous system impulses are examples of ________ stimuli for hormone release.

A) neural; humoral
B) positive; negative
C) negative; positive
D) humoral; neural

A blow to the shoulder often breaks the clavicle, but very seldom breaks the scapula. Which of the following statements best explains why this is so?

A) The scapula is larger than the clavicle.
B) The clavicle provides the only bony attachment of the pectoral girdle to the body.
C) The scapula is more protected by muscle.
D) When the body is moving forward, the clavicle is more likely to be struck than the scapula.
E) All of the choices are correct.

Vascular tissues distribute water and solutes through ground tissue. In ____, water and ions flow through tubes of dead tracheids and vessel elements.

A) sclerenchyma
B) parenchyma tissue
C) ground tissue
D) xylem
E) phloem

The structure that regulates the size of the opening for light in the eye is the

A) pupil.
B) retina.
C) iris.
D) ciliary muscle.
E) lens.

Which statement is true about steroid hormones?

A) Insulin is a steroid hormone.
B) Steroids bind to cell surface receptors.
C) Steroid hormones act faster than peptide hormones.
D) The hormone-receptor complex can enter the nucleus.
E) Steroid hormones have different complexes of 4-carbon rings.

The protist that is most closely related to animals is the ____.

A) amoeba
B) choanoflagellate
C) dinoflagellate
D) euglenoid
E) paramecium

A water-vascular system is unique to the ____.

A) arthropods
B) annelids
C) chordates
D) mollusks
E) echinoderms

Sugars and other organic solutes are conducted through the plant in which tissue?

A) cortex
B) parenchyma
C) xylem
D) phloem
E) cambium