antigenic variation a common strategy used by some viruses allows them to

ATI TEAS 7

TEAS Test 7 science quizlet

1. Antigenic variation, a common strategy used by some viruses, allows them to:

A. Produce toxins
B. Evade the immune system
C. Survive outside a host
D. Replicate rapidly

Correct answer: B

Rationale: Antigenic variation is a strategy used by some viruses to evade the host's immune response. By constantly changing their surface antigens, viruses can avoid recognition and destruction by the immune system. This allows the virus to persist in the host and continue replicating, leading to prolonged infection and potential transmission to other hosts. Antigenic variation does not directly involve the production of toxins, survival outside a host, or rapid replication, making options A, C, and D incorrect in this context.

2. How do organisms maintain homeostasis?

A. By increasing their body temperature, blood pH, and fluid balance.
B. By undergoing biochemical processes and absorbing energy to increase entropy.
C. By undergoing biochemical processes to maintain the order of their external environment.
D. By using free energy and matter via biochemical processes to work against entropy.

Correct answer: D

Rationale: Organisms maintain homeostasis by utilizing free energy and matter through biochemical processes to counteract entropy, which helps in preserving internal stability. This process involves maintaining a balance within the organism's internal environment despite external changes, ensuring proper functioning and survival. Choice A is incorrect because increasing body temperature, blood pH, and fluid balance alone do not define the comprehensive process of maintaining homeostasis. Choice B is incorrect as absorbing energy to increase entropy goes against the concept of maintaining internal stability. Choice C is incorrect as maintaining the order of the external environment does not directly contribute to the organism's internal stability and balance.

3. What do large intestines absorb?

A. Water, sodium, and potassium ions
B. Proteins and carbohydrates
C. Water, vitamin K, and bile salts
D. Vitamins A, D, E, K

Correct answer: C

Rationale: The correct answer is C. The large intestine absorbs water, vitamin K, bile salts, sodium, and chloride ions. It helps in maintaining the body's water and electrolyte balance, and also plays a role in absorbing certain vitamins and nutrients such as vitamin K. Choices A, B, and D are incorrect because proteins, carbohydrates, vitamins A, D, E, and K are primarily absorbed in the small intestine, not the large intestine.

4. What are Mendel's laws?

A. Law of inheritance, law of expression
B. Law of segregation, law of independent assortment
C. Law of dominance, law of recessiveness
D. Law of mutation, law of crossing over

Correct answer: B

Rationale: The correct answer is B. Mendel's laws consist of the law of segregation, which states that each parent passes one allele for each trait, and the law of independent assortment, which explains that genes for different traits are inherited independently. Choice A is incorrect because 'law of expression' is not one of Mendel's laws. Choice C is incorrect because 'law of dominance' and 'law of recessiveness' do not represent the two main laws proposed by Mendel. Choice D is incorrect because 'law of mutation' and 'law of crossing over' are not part of Mendel's original laws.

5. What term describes the front of the body, for example, the kneecap?

A. Posterior
B. Anterior
C. Superior
D. Inferior

Correct answer: B

Rationale: The correct answer is 'B: Anterior.' In anatomy, 'anterior' refers to the front of the body, like the kneecap. On the other hand, 'posterior' describes the back of the body. Choices 'C: Superior' and 'D: Inferior' relate to structures being above or below a reference point, respectively, and are not used to describe the front or back of the body. Therefore, 'Anterior' is the most appropriate term given the context provided in the question.