During swallowing food, which structure moves downward to prevent food from entering the trachea?

In plants, most chloroplasts are inherited from the maternal plant because maternal gametes contribute the most __________ to the zygote.

A. cytoplasm B. mitochondria C. ribosomes D. chlorophyll E. cytoplasm and mitochondria

The 10,000 origins of replication in mammalian cells suggests that there is

A) at least one origin of replication per loop of DNA. B) probably one origin of replication every other loop of DNA C) a random distribution of origins of replication across the genome. D) an even distribution of origins of replication across the genome.

Clostridium tetani, the bacterium that causes tetanus, can only survive in soil away from oxygen. It is considered which of the following?

A. an autotroph B. an obligate anaerobe C. a facultative anaerobe D. aerobic E. a phototroph

In a catalyzed reaction a reactant is often called a _______.

Fill in the blank(s) with the appropriate word(s).