when human cells divide by meiosis how many chromosomes do the resulting cells contain

ATI TEAS 7

Science TEAS Practice Test

1. When human cells divide by meiosis, how many chromosomes do the resulting cells contain?

A. 96
B. 54
C. 46
D. 23

Correct answer: D

Rationale: When human cells divide by meiosis, the resulting cells contain 23 chromosomes. This is because meiosis is a cell division process that reduces the chromosome number by half, resulting in cells with a haploid number of chromosomes. In humans, the diploid number of chromosomes is 46. Therefore, after meiosis, the resulting cells have 23 chromosomes, ensuring the correct chromosome number is restored upon fertilization. Choices A, B, and C are incorrect as they do not represent the correct chromosome number resulting from meiosis in human cells.

2. 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.

3. Which statement most accurately compares and contrasts the structures of DNA and RNA?

A. Both DNA and RNA have 4 nucleotide bases. Three of the bases are the same, but the fourth base is thymine in DNA and uracil in RNA.
B. Both DNA and RNA have the same 4 nucleotide bases. However, the nucleotides bond differently in DNA compared to RNA.
C. Both DNA and RNA have different numbers of nucleotide bases. DNA is a double helix while RNA is a single strand.
D. Both DNA and RNA have a double helix structure. However, DNA contains 6 nucleotide bases and RNA contains 4 nucleotide bases.

Correct answer: A

Rationale: The correct answer is A because DNA and RNA both consist of 4 nucleotide bases, namely adenine, cytosine, and guanine, which are common in both. The key difference lies in the fourth base, which is thymine in DNA and uracil in RNA. This distinction is fundamental in understanding the structural variances between DNA and RNA. Choice B is incorrect as it incorrectly states that the nucleotides bond differently in DNA compared to RNA without specifying the crucial base differences. Choice C is inaccurate as it misrepresents the numbers of nucleotide bases in DNA and RNA, and incorrectly describes DNA as a double helix and RNA as a single strand, which is not related to the difference in bases. Choice D is incorrect as it inaccurately portrays DNA with 6 nucleotide bases and RNA with 4, which is not true; both DNA and RNA have 4 nucleotide bases, but with differences in one of the bases.

4. What is the main consequence of a malfunctioning thyroid gland that produces abnormally low levels of thyroid hormones?

A. Increased energy levels and weight loss
B. Decreased heart rate and body temperature
C. Enhanced muscle growth and bone development
D. Faster metabolism and heightened alertness

Correct answer: B

Rationale: The correct answer is B: Decreased heart rate and body temperature. A malfunctioning thyroid gland that produces abnormally low levels of thyroid hormones leads to hypothyroidism, resulting in decreased metabolic activity. This reduction in metabolic rate can cause a decreased heart rate and lower body temperature. Choices A, C, and D are incorrect because hypothyroidism typically manifests as symptoms such as fatigue, weight gain, cold intolerance, bradycardia, and decreased body temperature, rather than increased energy levels, enhanced muscle growth, faster metabolism, or heightened alertness.

5. What does 'monophyletic' mean in the context of classification?

A. A group with a single representative organism
B. A group with diverse and unrelated members
C. A group with similar functions but different origins
D. A group descended from a common ancestor

Correct answer: D

Rationale: In the context of classification, 'monophyletic' refers to a group that includes a common ancestor and all of its descendants. This group shares a single evolutionary origin and forms a complete branch on a phylogenetic tree. Monophyletic groups are considered natural and valid taxonomic units because they reflect evolutionary relationships accurately. Option D is the correct choice as it accurately defines the term 'monophyletic' in the context of classification. Choices A, B, and C are incorrect. Choice A is incorrect because 'monophyletic' does not refer to a group with a single representative organism but rather a group descended from a common ancestor. Choice B is incorrect as a monophyletic group consists of related, not diverse and unrelated, members. Choice C is incorrect as a monophyletic group includes descendants from a common ancestor, not just organisms with similar functions but different origins.