why can animal cells use a contractile ring but plant cells cannot

HESI A2

HESI A2 Biology Practice Test

1. Why can animal cells use a contractile ring but plant cells cannot?

A. Plant cells can use both methods to divide
B. Animal cells divide faster, requiring them to pinch apart
C. Plant cells are too rigid to use a contractile ring
D. N/A

Correct answer: C

Rationale: Plant cells have a rigid cell wall surrounding them, which prevents them from using a contractile ring for cell division. The rigid cell wall requires plant cells to form a cell plate during cell division instead of pinching apart like animal cells with a contractile ring. Choice A is incorrect because plant cells cannot use a contractile ring due to their rigid cell wall. Choice B is incorrect as the speed of cell division is not the primary reason for the difference in cell division mechanisms between plant and animal cells. Choice D is not applicable as plant cells indeed have a specific limitation in using a contractile ring for cell division.

2. Which bone does not articulate with any other bone in the body?

A. Scapula
B. Hyoid
C. Radius
D. Femur

Correct answer: B

Rationale: The correct answer is B: Hyoid. The hyoid bone is the only bone in the body that does not articulate with any other bones. It is located in the neck and supports the tongue and other muscles involved in swallowing and speech. The scapula articulates with the clavicle and humerus, the radius with the ulna and humerus, and the femur with the pelvis and tibia. Choices A, C, and D are incorrect because they all articulate with other bones in the body.

3. What is the main idea of the passage about Toxins and Your Health?

A. Environmental toxins may have dire health effects over time.
B. Of three toxins studied, lead has the worst effect on health.
C. Toxins may accumulate in the bones of older patients.
D. Johns Hopkins University has discovered a new use for lead.

Correct answer: A

Rationale: The passage emphasizes the long-term effects of environmental toxins such as lead, pesticides, and mercury on brain health, particularly as individuals age. Dr. Brian Schwartz's quote highlights the link between environmental exposure and cognitive decline, framing the entire discussion around the potential health ramifications of such exposure over time. This clearly aligns with choice A, making it the main idea of the passage.

4. How many pounds are in 176 ounces?

A. 15 pounds
B. 10 pounds
C. 12 pounds
D. 11 pounds

Correct answer: D

Rationale: To convert ounces to pounds, you divide the number of ounces by 16 since there are 16 ounces in a pound. Therefore, 176 ounces ÷ 16 = 11 pounds. Choice A is incorrect because it miscalculates the conversion. Choices B and C are also incorrect as they do not accurately convert the given ounces to pounds.

5. Select the word that makes the following sentence grammatically correct. One of the students ___________ completed the course.

A. have
B. has
C. are
D. is

Correct answer: B

Rationale: The correct word to use in this sentence is 'has' because 'One of the students' is singular, so it should be followed by a singular verb. The word 'has' is the correct singular form of the verb in this context. Choice A 'have' is plural, Choice C 'are' is also plural, and Choice D 'is' does not agree in number with the subject 'students'. Therefore, 'has' is the only correct choice here.