how does the structure of centromeres contribute to chromosome movement during mitosis

ATI TEAS 7

TEAS 7 science quizlet

1. How does the structure of centromeres contribute to chromosome movement during mitosis?

A. The centromere provides a binding site for spindle fibers, allowing chromosomes to be attached and manipulated.
B. The centromere serves as a dividing point between sister chromatids, ensuring their separation during anaphase.
C. The centromere maintains chromosome stability by preventing chromosomal breaks and rearrangements.
D. The centromere plays a role in DNA replication, ensuring accurate copying of the genetic material.

Correct answer: A

Rationale: A) The centromere provides a binding site for spindle fibers, which are microtubules that help move chromosomes during cell division. This attachment allows the chromosomes to be pulled towards opposite poles of the cell during mitosis. Therefore, the structure of centromeres directly contributes to chromosome movement during mitosis by facilitating the attachment and manipulation of chromosomes by the spindle fibers. B) While the centromere does serve as a dividing point between sister chromatids, ensuring their separation during anaphase, this function is more related to the segregation of chromosomes rather than their movement. C) The centromere does play a role in maintaining chromosome stability by ensuring proper chromosome segregation, but it is not primarily responsible for preventing chromosomal breaks and rearrangements. D) The centromere is not directly involved in DNA replication. Its main function is

2. What is the primary function of the digestive system?

A. To break down food into nutrients
B. To absorb oxygen
C. To produce energy
D. To regulate body temperature

Correct answer: A

Rationale: The correct answer is A: 'To break down food into nutrients.' The primary function of the digestive system is to break down food into nutrients that can be absorbed by the body for energy, growth, and repair. The digestive system is not responsible for absorbing oxygen (Choice B), as that is the role of the respiratory system. While the digestion process does release energy from nutrients, the primary function is not to produce energy (Choice C), but rather to extract nutrients for energy production. Regulating body temperature (Choice D) is primarily handled by the thermoregulatory mechanisms in the body, such as the skin and sweat glands, not the digestive system.

3. What is the hypodermis composed of?

A. Epithelial tissue
B. Adipose and areolar connective tissue
C. Collagen fibers
D. Dense connective tissue

Correct answer: B

Rationale: The correct answer is B: Adipose and areolar connective tissue. The hypodermis, also known as the subcutaneous layer, is primarily composed of adipose (fat) and areolar (loose) connective tissue. These tissues provide insulation, cushioning, and energy storage. Epithelial tissue (Choice A) is not a significant component of the hypodermis, as it is mainly found in the epidermis and lining of internal organs. Collagen fibers (Choice C) are more abundant in the dermis, providing strength and support. Dense connective tissue (Choice D) is also present in the dermis but is not a major component of the hypodermis.

4. What does the phrase 'survival of the fittest' refer to?

A. Organisms with the most complex anatomical structures are more likely to survive and reproduce.
B. Organisms that demonstrate the best adaptations to their environment have a higher chance of survival and reproduction.
C. All organisms have an equal probability of survival and reproductive success regardless of their traits.
D. Only the strongest and most aggressive individuals within a population will survive and reproduce.

Correct answer: B

Rationale: The phrase 'survival of the fittest' is often associated with the concept of natural selection, proposed by Charles Darwin. Natural selection is the process by which organisms best adapted to their environment are more likely to survive and reproduce, passing on their advantageous traits to the next generation. This process does not necessarily favor the most complex anatomical structures (option A) or the strongest and most aggressive individuals (option D). Instead, it emphasizes the importance of adaptations that enhance an organism's ability to survive and reproduce in a specific environment. Option C is incorrect because natural selection results in differential reproductive success based on an organism's traits, meaning that not all organisms have an equal probability of survival and reproductive success.

5. Two identical balls, one made of clay and the other made of steel, are dropped from the same height. Which ball reaches the ground first, neglecting air resistance?

A. The clay ball due to its lower density
B. The steel ball due to its higher density
C. Both balls reach the ground simultaneously
D. It depends on the initial velocities of the balls

Correct answer: C

Rationale: In the absence of air resistance, both balls will experience the same acceleration due to gravity (9.8 m/s^2) regardless of their densities or materials. This means that both balls will reach the ground at the same time, assuming they are dropped from the same height simultaneously. The differences in density or material composition do not affect the rate at which objects fall in a vacuum. Therefore, both the clay and steel balls, being identical in shape and starting position, will have the same free-fall acceleration and will hit the ground simultaneously. Choices A and B are incorrect because the density of the materials does not impact the time it takes for objects to fall under gravity alone. Choice D is incorrect as the initial velocities do not play a role in the time taken to fall in a vacuum, where only the acceleration due to gravity affects the motion.