if an organism is ab which of the following combinations in the gametes is not possible

ATI TEAS 7

Science TEAS Practice Test

1. If an organism is AB, which of the following combinations in the gametes is NOT possible?

A. AB
B. AA
C. BB
D. AB

Correct answer: B

Rationale: The correct answer is B. If an organism is AB, it indicates that it carries two different alleles. During gamete formation, each gamete receives only one allele from the pair present in the organism. Therefore, in this case, the possible gametes would be 'A' and 'B,' making 'AA' impossible. Choice A, 'AB,' is possible as each gamete can carry one of the alleles from the genotype. Similarly, 'BB' is also possible if one of the alleles separates into a gamete. Choice D, 'AB,' is essentially the same genotype as the organism and is a possible combination in the gametes.

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. Which nervous system controls voluntary motor movement?

A. Parasympathetic
B. Sympathetic
C. Autonomic
D. Somatic

Correct answer: D

Rationale: The correct answer is D: Somatic. The somatic nervous system is responsible for controlling voluntary motor movements. It includes the motor neurons that innervate skeletal muscles and allows us to consciously control our movements. The parasympathetic and sympathetic nervous systems are part of the autonomic nervous system, which controls involuntary functions such as heart rate and digestion. Therefore, choices A, B, and C are incorrect as they are components of the autonomic nervous system and are not primarily responsible for voluntary motor movements.

4. What is the SI unit of measurement for acceleration?

A. Meters per second (m/s)
B. Newton (N)
C. Meters (m)
D. Meters per second squared (m/s²)

Correct answer: D

Rationale: The SI unit of measurement for acceleration is meters per second squared (m/s²). Acceleration is defined as the rate of change of velocity over time. It is a vector quantity with dimensions of length per time squared. Meters per second squared (m/s²) represents the change in velocity (meters per second) over a specific time interval (seconds) squared. Choice A, meters per second (m/s), represents velocity, not acceleration. Choice B, Newton (N), is the unit of force. Choice C, Meters (m), represents only distance, not acceleration. Therefore, the correct unit for acceleration is meters per second squared (m/s²).

5. Why are elements in Group 18 (Noble gases) generally unreactive?

A. They have high atomic masses
B. They lack valence electrons
C. Their outermost electron shells are completely filled
D. They exist as single atoms, not molecules

Correct answer: C

Rationale: Elements in Group 18 (Noble gases) are generally unreactive because their outermost electron shells are completely filled. This results in high stability and low reactivity since they have achieved a full valence shell configuration, making them less likely to gain, lose, or share electrons with other atoms. The full valence shell configuration leads to a minimal tendency for these elements to form chemical bonds, hence exhibiting low reactivity. Choices A, B, and D are incorrect because high atomic masses, lack of valence electrons, and existing as single atoms do not directly contribute to the unreactivity of noble gases. It is the full valence shell configuration that is the primary reason for their inert nature.