TEAS 7 Biology: Master Key Concepts

ATI TEAS 7

Biology

1. What is the process by which a population gradually loses genetic variation?

A. Founder effect
B. Bottleneck effect
C. Gene flow
D. Speciation

Correct answer: B

Rationale: Rationale: A) Founder effect: This occurs when a small group of individuals establishes a new population, leading to a loss of genetic variation compared to the original population. It does not necessarily result in a gradual loss of genetic variation in an existing population. B) Bottleneck effect: This process occurs when a population is drastically reduced in size, leading to a significant loss of genetic variation due to the limited number of individuals contributing to the gene pool. The reduced genetic diversity can have long-term effects on the population's ability to adapt to environmental changes. C) Gene flow: This refers to the movement of genes between populations, which can introduce new genetic variation and prevent populations from diverging. Gene flow does not lead to a gradual loss of genetic variation within a population. D) Speciation: This is the process by which new species evolve from existing species, often involving the accumulation of genetic differences that l

2. The adaptive immune system develops a targeted response to specific pathogens. What type of immune cell is responsible for producing antibodies?

A. Natural killer cells
B. Phagocytes
C. Helper T cells
D. B cells

Correct answer: D

Rationale: The correct answer is D: B cells. B cells are a type of lymphocyte responsible for producing antibodies, which play a crucial role in the adaptive immune response. When a pathogen enters the body, B cells are activated and differentiate into plasma cells that secrete specific antibodies to target and neutralize the pathogen. Natural killer cells (A) are part of the innate immune system and are responsible for killing infected or abnormal cells. Phagocytes (B) are another type of innate immune cell that engulfs and digests pathogens. Helper T cells (C) play a vital role in coordinating the immune response but do not directly produce antibodies.

3. The control center of the cell, containing genetic information (DNA), is the:

A. Golgi apparatus
B. Ribosome
C. Nucleus
D. Endoplasmic reticulum

Correct answer: C

Rationale: The correct answer is C: Nucleus. The nucleus is the control center of the cell as it contains the cell's genetic material, DNA. It acts as the brain of the cell, regulating gene expression and controlling cell activities. The Golgi apparatus is responsible for packaging and processing proteins, the ribosomes are involved in protein synthesis, and the endoplasmic reticulum is essential for protein and lipid synthesis. However, none of these organelles house the genetic information of the cell, making the nucleus the correct answer in this case.

4. Myelin sheath is a fatty substance that insulates and protects the long extensions of some nerve cells. It is produced by:

A. Schwann cells
B. Astrocytes
C. Neurons
D. Oligodendrocytes

Correct answer: A

Rationale: The correct answer is A: Schwann cells. Schwann cells are a type of glial cell in the peripheral nervous system that produce the myelin sheath around axons. Myelin sheath is essential for the rapid conduction of nerve impulses and provides insulation and protection to nerve fibers. Astrocytes are glial cells that provide support and maintain homeostasis in the central nervous system, but they do not produce myelin. Neurons are the main functional units of the nervous system responsible for transmitting nerve impulses. Oligodendrocytes are another type of glial cell in the central nervous system that produce myelin sheath around axons in that region, not in the peripheral nervous system where Schwann cells are responsible for myelination.

5. What skin condition is characterized by red, itchy, and inflamed patches?

A. Eczema
B. Psoriasis
C. Melanoma
D. Keloid

Correct answer: A

Rationale: The correct answer is A: Eczema. Eczema is a common skin condition that is characterized by red, itchy, and inflamed patches on the skin. It is often triggered by environmental factors or allergies and can vary in severity. Psoriasis (option B) is also a skin condition that causes red, scaly patches on the skin, but it is typically thicker and more silver or white in color compared to eczema. Melanoma (option C) is a type of skin cancer that usually presents as a new mole or a changing mole on the skin, rather than red, itchy patches. Keloid (option D) is a raised scar that can result from an overgrowth of scar tissue. Therefore, the most appropriate answer to this question is A: Eczema, based on the description of red, itchy, and inflamed patches.