at the beginning of meiosis how many chromosomes does the diploid parent cell have

HESI RN

Biology Test

1. At the beginning of meiosis, how many chromosomes does the diploid parent cell have?

A. 23
B. 24
C. 46
D. 54

Correct answer: C

Rationale: The correct answer is C: 46. At the start of meiosis, the diploid parent cell contains 46 chromosomes. During meiosis, the number of chromosomes is halved, resulting in each gamete having 23 chromosomes. Choice A (23) is incorrect because that is the number of chromosomes in a human gamete, not the parent cell. Choice B (24) and Choice D (54) are also incorrect as they do not reflect the correct number of chromosomes in a diploid parent cell at the beginning of meiosis.

2. What is the smallest and most basic unit of matter?

A. Micromolecule
B. Atom
C. Organelle
D. Molecule

Correct answer: B

Rationale: The correct answer is B, Atom. An atom is the smallest unit of matter that retains the properties of an element. Choice A, Micromolecule, is incorrect because molecules are composed of atoms bonded together, making them larger than individual atoms. Choice C, Organelle, is incorrect as organelles are structures within cells, not the basic unit of matter. Choice D, Molecule, is incorrect as molecules are made up of atoms bonded together, so they are not the smallest unit of matter.

3. Prophase is the first stage of mitosis. Which of the following best describes chromosomes during this stage?

A. They are gathered on either side of the separating cell
B. They are all aligned along the metaphase plate
C. They are attached to the spindle
D. They are visibly separate

Correct answer: D

Rationale: The correct answer is D. During prophase, the chromosomes condense and become visible as distinct structures under a microscope. Choice A is incorrect as chromosomes are not gathered on either side of the separating cell during prophase. Choice B is incorrect because chromosomes align along the metaphase plate during the subsequent stage, metaphase. Choice C is incorrect as chromosomes become attached to the spindle fibers during prometaphase, the stage following prophase.

4. What is the most important function of carbohydrates?

A. Store and provide energy for the body
B. Create amino acids
C. Maintain body temperature
D. Insulate body organs against shock

Correct answer: A

Rationale: The most important function of carbohydrates is to store and provide energy for the body through metabolic processes. Carbohydrates are broken down into glucose, which is used as the primary source of energy for various cellular functions. Choice B is incorrect because amino acids are the building blocks of proteins, not directly created by carbohydrates. Choice C is incorrect as the regulation of body temperature is primarily controlled by mechanisms such as sweating and shivering, not carbohydrates. Choice D is incorrect as insulation of body organs against shock is mainly provided by adipose tissue, not carbohydrates.

5. A molecule's specific heat is the amount of heat necessary to raise the temperature of 1 gram of that molecule by:

A. One degree Celsius
B. Five degrees Celsius
C. Two degrees Celsius
D. Four degrees Celsius

Correct answer: A

Rationale: The correct answer is A: 'One degree Celsius.' Specific heat is defined as the amount of heat required to raise the temperature of one gram of a substance by one degree Celsius. This property is specific to each substance and is used in various calculations involving heat and temperature changes. Choices B, C, and D are incorrect because specific heat is always measured per one degree Celsius increase in temperature for one gram of the substance, not five degrees, two degrees, or four degrees.