TEAS 7 Biology: Master Key Concepts

ATI TEAS 7

Biology

1. Which of the following is NOT a source of genetic variation in a population?

A. Mutations in genes
B. Genetic drift (random fluctuations in allele frequencies)
C. Gene flow (movement of genes between populations)
D. Blending inheritance (traits of parents are averaged in offspring)

Correct answer: D

Rationale: Rationale: A) Mutations in genes: Mutations are changes in the DNA sequence that can introduce new alleles into a population, leading to genetic variation. B) Genetic drift (random fluctuations in allele frequencies): Genetic drift refers to random changes in allele frequencies in a population, which can lead to genetic variation through chance events. C) Gene flow (movement of genes between populations): Gene flow occurs when individuals move between populations, bringing new alleles with them and increasing genetic variation within populations. D) Blending inheritance (traits of parents are averaged in offspring): Blending inheritance was a historical theory that suggested offspring inherit a blend of traits from their parents, leading to a reduction in genetic variation over time. However, this concept has been disproven by the understanding of Mendelian genetics, where traits are inherited independently and do not blend together. Therefore, blending inheritance does not contribute

2. Which hormone is responsible for regulating sleep-wake cycles and is influenced by light exposure?

A. Melatonin
B. Cortisol
C. Estrogen
D. Glucagon

Correct answer: A

Rationale: The correct answer is A: Melatonin. Melatonin is a hormone produced by the pineal gland in the brain and plays a crucial role in regulating the sleep-wake cycle, also known as the circadian rhythm. Melatonin levels typically rise in the evening in response to darkness and help signal to the body that it's time to sleep. Exposure to light, especially blue light, can inhibit the production of melatonin, making us more alert and awake. Cortisol (option B) is a stress hormone that helps regulate metabolism and immune response. Estrogen (option C) is a female sex hormone, and glucagon (option D) is a hormone that increases blood sugar levels. Therefore, the hormone responsible for regulating sleep-wake cycles and influenced by light exposure is melatonin.

3. What is the difference between alpha decay and beta decay?

A. Both release the same type of particle.
B. Alpha decay releases a helium nucleus, while beta decay releases an electron or positron.
C. Alpha decay is more common than beta decay.
D. They both convert one element into another, but in different ways.

Correct answer: B

Rationale: Alpha decay releases a helium nucleus (2 protons, 2 neutrons), while beta decay releases an electron or positron. - Both processes alter the atomic structure and change the element's identity.

4. Which property of a substance describes how much matter is packed into a given space?

A. Mass
B. Volume
C. Weight
D. Density

Correct answer: D

Rationale: Density is the property of a substance that describes how much matter is packed into a given space. It is calculated by dividing the mass of the substance by its volume. Mass refers to the amount of matter in an object, volume is the amount of space an object occupies, and weight is the force of gravity acting on an object's mass. Density specifically relates to how tightly packed the particles of a substance are.

5. What is the term for the transfer of energy through a food chain?

A. Photosynthesis
B. Cellular respiration
C. Transpiration
D. Trophic cascade

Correct answer: D

Rationale: Rationale: A) Photosynthesis is the process by which green plants and some other organisms use sunlight to synthesize foods with the help of chlorophyll. B) Cellular respiration is the process by which cells break down glucose and other molecules to produce energy in the form of ATP. C) Transpiration is the process by which water is absorbed by plant roots, moves through the plant, and is released as vapor through pores in the leaves. D) Trophic cascade refers to the transfer of energy through a food chain or food web, where the impact of a predator on its prey cascades down the food chain, affecting multiple trophic levels. This term describes the indirect effects that predators can have on lower trophic levels, influencing the entire ecosystem.