which stage of mitosis is occurring when the nuclear envelope begins to disappear and the chromosomes begin to attach to the spindle that is forming a

HESI RN

Biology Test

1. During which stage of mitosis does the nuclear envelope begin to disappear and the chromosomes start attaching to the spindle forming along the cell's axis?

A. Prometaphase
B. Metaphase
C. Anaphase
D. Prophase

Correct answer: A

Rationale: The correct answer is A, Prometaphase. During prometaphase, the nuclear envelope disintegrates, and chromosomes start attaching to spindle fibers. In metaphase, chromosomes align in the middle of the cell. Anaphase is characterized by the separation of sister chromatids, and prophase involves the condensation of chromosomes and the beginning of spindle formation.

2. DNA and RNA are both subunits of which biological molecule?

A. Nucleic acids
B. Proteins
C. Carbohydrates
D. Lipids

Correct answer: A

Rationale: The correct answer is A: Nucleic acids. DNA and RNA are both types of nucleic acids, which are fundamental biological molecules responsible for storing and transmitting genetic information. Choice B, Proteins, are not subunits of DNA and RNA but are composed of amino acids. Carbohydrates, choice C, are another type of biological molecule involved in energy storage and structural support, not subunits of DNA and RNA. Lipids, choice D, are a diverse group of molecules that include fats, oils, and steroids, but they are not subunits of DNA and RNA.

3. The liver is an organ responsible for detoxifying the body of many harmful substances. You might expect the liver to contain a high amount of which of the following?

A. Rough endoplasmic reticulum
B. Smooth endoplasmic reticulum
C. Mitochondria
D. Lysosomes

Correct answer: B

Rationale: The correct answer is B: Smooth endoplasmic reticulum. The liver contains a high amount of smooth endoplasmic reticulum because it plays a significant role in detoxification processes, such as the synthesis of detoxifying enzymes and lipids. Choice A (Rough endoplasmic reticulum) is incorrect because the rough endoplasmic reticulum is more involved in protein synthesis and processing. Choice C (Mitochondria) is incorrect as mitochondria are primarily responsible for energy production. Choice D (Lysosomes) is incorrect because lysosomes are organelles involved in intracellular digestion and waste removal, not specifically related to detoxification.

4. In the hierarchy of biology, cells combine to form which of the following?

A. Macromolecules
B. Molecules
C. Tissues
D. Organelles

Correct answer: C

Rationale: In the hierarchy of biology, cells combine to form tissues. Tissues are groups of cells that work together to perform specific functions. This is a fundamental level of organization above individual cells but below organs and organ systems. Macromolecules and molecules are smaller components that make up cells, not what cells combine to form. Organelles are structures within cells that perform specific functions and do not result from the combination of cells.

5. 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.