MTTC Biology Flashcards

Which of the following is an example of a density-dependent limiting factor on a population?

Answer: Competition for food resources

Density-dependent factors like intraspecific competition intensify as population density increases, regulating population growth.

During which stage of embryonic development does gastrulation produce the three primary germ layers?

Answer: Gastrula

Gastrulation transforms the blastula into a gastrula, forming the three germ layers: ectoderm, mesoderm, and endoderm.

A biome characterized by permafrost, very low precipitation, and dominated by mosses and lichens is:

Answer: Tundra

The tundra biome has permanently frozen subsoil (permafrost), extremely low precipitation, and supports only cold-adapted vegetation like mosses, lichens, and grasses.

Which type of symbiosis benefits one organism while the other is neither harmed nor helped?

Answer: Commensalism

In commensalism, one organism benefits and the other is unaffected; an example is barnacles attaching to a whale.

Which structure connects a muscle to a bone?

Answer: Tendon

Tendons are dense connective tissue that attach skeletal muscles to bones, transmitting the force of muscle contraction to move the skeleton.

A plant cell in a hypertonic solution undergoes plasmolysis. Which of the following describes this condition?

Answer: The plasma membrane pulls away from the cell wall as water leaves

Plasmolysis occurs when water leaves a plant cell by osmosis into a hypertonic environment, causing the plasma membrane to shrink away from the rigid cell wall.

Which of the following best explains why the Hardy-Weinberg equilibrium is rarely observed in natural populations?

Answer: Natural populations always experience mutation, selection, and genetic drift

Hardy-Weinberg equilibrium requires no mutation, random mating, no selection, infinite population size, and no gene flow — conditions virtually impossible in nature.