Approximately how much of the energy available in the tissues of the producer is eventually incorporated into the tissues of a secondary consumer?

More than 50% Less than 1%

Between 20% and 30% Approximately 50%

An oakworm caterpillar feeds on the leaves of

an oak tree. This type of interaction is —

mutualistic commensalistic

parasitic competitive

Which of the following is most likely to cause

increases in a predator population?

A reduction in competition

Fewer prey

More parasites A period of drought

Which organisms in this food web can be described as both primary and secondary consumers?

Hawks Mice

Weasels Raccoons

Wolves and hawks are at the same trophic level because they —

A both live on land both eat primary

consumers

are both large mammals have similar hunting patterns

Which body system is directly responsible for delivering nutrients to cells throughout the body?

Integumentary system

Circulatory system

Endocrine system Respiratory system

Most viruses infect a specific kind of cell. Which of the following are infected by the human immunodeficiency virus (HIV)?

Helper T cells

GABA-receptor cells Red blood cells

Liver cells

Viruses differ from bacteria in that all viruses —

have rigid cell walls cause insect-borne diseases

must be reproduced in living cells

can be destroyed by antibiotics

In DNA, which of the following determines the traits of an organism?

Sequence of nitrogen bases

Number of sugars

Strength of hydrogen bonds

Amount of adenine

Dogs (Canis familiaris) are most closely related genetically to which of the following organisms?

Grizzly bear (Ursus arctos)

African hunting dog (Lycaon pictus)

Gray wolf (Canis lupus)

Domestic cat (Felis catus)

A laboratory investigation included examining prepared slides of pond water. Single-celled organisms with a nucleus and either cilia or flagella were visible. These organisms probably belong to the kingdom —

Plantae Fungi

Protista Animalia

Which structure regulates gas exchange during the processes of photosynthesis and respiration?

S R

T Q

Which of the following characteristics could help short plants survive in areas with limited sunlight?

Brightly colored flowers

Broad leaf surfaces

Thick stems Shallow roots

This diagram shows the biochemical pathway that produces arginine in Neurospora, a mold. Neurospora is easily grown on a simple jelly-like medium. Different substances can be added to the medium. A mutant Neurospora lacking Enzyme Y would have to have which of these added to its medium in order to survive?

Citrulline Enzyme X

Ornithine Enzyme Z

In this food pyramid, which level contains thegreatest amount of energy?

Producers Primary consumers

Secondary consumers

Tertiary consumers