The human body is made up of specialized cells that perform different functions. For example, a neuron is a specialized cell of the nervous system that receives and transmits signals throughout the body. To perform these tasks, the neuron uniquely possesses branched protoplasmic protrusions, called dendrites and axons, which conduct the signals to and from its cell body. This illustrates which of the five major biological themes?

A) interaction among biological systems
B) evolution
C) interrelation of structure and function in biological systems
D) activity of living cells
E) transmission of information within and among organisms

Lamarck's ideas on evolution were adopted by some Russian scientists, including Lysenko. Russian textbooks printed Lysenko's assertion that workmen who develop strong muscles from working in the mines would produce children who would be born stronger. Which of the major elements of evolution by natural selection is violated by this assertion?

A) Organisms vary in traits.
B) Acquired characteristics are inherited.
C) More young are born than can survive.
D) Some individuals are better adapted to the environment.
E) The environment selects for phenotype.

Which are deuterostomes?

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

Male pigs have a retractable penis that can be withdrawn into which orifice?

A) external urogenital orifice
B) renal capsule
C) urinary bladder
D) urogenital sinus