binding membrane of an animal cell is called

HESI A2

HESI A2 Biology Practice Test

1. What is the binding membrane of an animal cell called?

A. Biological membrane
B. Cell coat
C. Unit membrane
D. Plasma membrane

Correct answer: D

Rationale: The correct answer is D: Plasma membrane. The plasma membrane surrounds the cell and acts as an interface between the living interior of the cell and the nonliving exterior. It plays a vital role in maintaining the cell's integrity, regulating the passage of substances in and out of the cell, and facilitating communication with other cells. Choices A, B, and C are incorrect because the term 'plasma membrane' specifically refers to the binding membrane of an animal cell, distinguishing it from other types of membranes or coatings found in cells.

2. Ocean waves may tear sponges into pieces, each of which may grow into a new sponge. What is this form of reproduction called?

A. Budding
B. Vegetative propagation
C. Binary fission
D. Fragmentation

Correct answer: D

Rationale: Fragmentation is the form of asexual reproduction where an organism breaks into fragments, and each fragment can grow into a new individual. In the case of sponges being torn into pieces by ocean waves, each piece has the potential to develop into a new sponge, making fragmentation the correct answer in this scenario. Budding is a form of asexual reproduction where a new organism develops as an outgrowth from the parent organism. Vegetative propagation involves the growth of new individuals from plant parts like stems or roots. Binary fission is a method of reproduction seen in some single-celled organisms where one cell divides into two identical cells.

3. If bacteria are placed in a strong solution of salt water, they will shrink as water moves out of the bacteria. What is this process called?

A. Dehydration synthesis
B. Hydrolysis
C. Osmosis
D. Isotonic transport

Correct answer: C

Rationale: Osmosis is the process by which water molecules move across a semipermeable membrane from an area of lower solute concentration to an area of higher solute concentration. In this case, when bacteria are placed in a strong solution of salt water, the high concentration of solutes outside the bacteria causes water to move out of the bacteria, leading to shrinkage. This process is known as osmosis. Dehydration synthesis (Choice A) is a process where molecules combine by removing water. Hydrolysis (Choice B) is the breakdown of molecules by the addition of water. Isotonic transport (Choice D) does not accurately describe the specific movement of water in or out of bacterial cells in a hypertonic solution.

4. How should a researcher test the hypothesis that eating chocolate leads to acne in teenagers?

A. Take 100 teenagers and feed each one a different amount of chocolate daily for 60 days; then test for acne.
B. Take 100 teenagers and feed 50 two bars of chocolate daily for 60 days while the other 50 eat no chocolate; then test for acne.
C. Take 1 teenager and feed him or her two bars of chocolate for 30 days and no chocolate for 30 days; then test for acne.
D. Take 100 teenagers and feed them no chocolate for 30 days and two bars of chocolate apiece for 30 days; then test for acne.

Correct answer: B

Rationale: Option B is the correct approach to test the hypothesis that eating chocolate leads to acne in teenagers. This method involves having a control group (50 teenagers not consuming chocolate) and an experimental group (50 teenagers consuming two bars of chocolate daily), which allows for comparison. By having two distinct groups, researchers can assess the impact of chocolate consumption on acne development. Option A lacks a control group for comparison, making it harder to attribute any observed effects specifically to chocolate consumption. Option C only involves a single subject, which limits the generalizability of the results. Option D, where all teenagers experience both conditions, does not allow for a direct comparison between chocolate consumption and acne development, as all subjects are exposed to both conditions.

5. What is the magnification of an ocular lens on a microscope?

A. 4x
B. 10x
C. 40x
D. 100x

Correct answer: B

Rationale: The magnification of an ocular lens on a microscope is typically 10x, which is considered standard for most microscopes. Ocular lenses are designed to magnify the image produced by the objective lens further. Choices A, C, and D are incorrect because they do not represent the standard magnification of an ocular lens. A magnification of 4x, 40x, or 100x would not be typical for an ocular lens in a microscope.