what of the following cations is found at the center of a heme

ATI TEAS 7

Practice Science TEAS Test

1. Which of the following cations is found at the center of a heme?

A. Cr (III)
B. Cu (II)
C. Iron (II)
D. Iron (III)

Correct answer: C

Rationale: The correct answer is Iron (II) (Fe2+), which is the cation found at the center of a heme group. Heme contains an iron (II) ion that is coordinated within the porphyrin ring structure. This iron ion is crucial for the function of heme in binding and transporting oxygen in hemoglobin and myoglobin. Choice A (Cr (III)) is incorrect as chromium is not typically found at the center of a heme group. Choice B (Cu (II)) is incorrect as copper is not the cation typically present in heme. Choice D (Iron (III)) is also incorrect as heme predominantly contains iron (II) at its center, not iron (III).

2. What is the difference between a germline mutation and a somatic mutation?

A. Germline mutations are passed to offspring, while somatic mutations are not.
B. Germline mutations occur in reproductive cells, while somatic mutations occur in body cells.
C. Germline mutations only affect genes, while somatic mutations can affect any DNA.
D. Germline mutations are always beneficial, while somatic mutations are always harmful.

Correct answer: B

Rationale: Rationale: - Germline mutations are changes in the DNA of reproductive cells (sperm or egg cells) and can be passed on to offspring, affecting all cells in the resulting organism. - Somatic mutations are changes in the DNA of non-reproductive cells (body cells) and are not passed on to offspring. These mutations only affect the cells that arise from the mutated cell. - Option A is incorrect because somatic mutations are not passed to offspring. - Option C is incorrect because both germline and somatic mutations can affect any DNA. - Option D is incorrect because the effects of mutations, whether germline or somatic, can be beneficial, harmful, or have no significant impact.

3. An uncharged atom has an electron configuration of 1s2 2s2 2p6 3s2 and a mass number of 14. How many protons does it have?

A. 14
B. 6
C. 8
D. 12

Correct answer: B

Rationale: The correct answer is B (6 protons). The electron configuration provided corresponds to the element carbon, which has 6 protons. The mass number does not affect the number of protons in an atom, so despite the mass number of 14, the atom still contains 6 protons. Choice A (14) is incorrect because the mass number does not determine the number of protons. Choices C (8) and D (12) are incorrect as they do not match the number of protons in a carbon atom.

4. What is the function of the alveoli in the lungs?

A. To exchange carbon dioxide for oxygen
B. To transport air to the lungs
C. To filter blood
D. To produce mucus

Correct answer: A

Rationale: The corrected answer is A: 'To exchange carbon dioxide for oxygen.' The alveoli in the lungs are responsible for facilitating gas exchange, where oxygen from inhaled air diffuses into the bloodstream, and carbon dioxide from the bloodstream diffuses into the alveoli to be exhaled. This process is vital for respiration and maintaining proper oxygen levels in the body. Choices B, C, and D are incorrect. Choice B is incorrect because the alveoli are not involved in transporting air to the lungs; they are primarily responsible for gas exchange. Choice C is incorrect because the alveoli do not filter blood; their main function is gas exchange. Choice D is incorrect because alveoli do not produce mucus; mucus is produced by other specialized cells in the respiratory system.

5. Which of the following is another name for a sweat gland?

A. Ceruminous
B. Sebaceous
C. Sudoriferous
D. Integumentary

Correct answer: C

Rationale: The correct answer is C: Sudoriferous. Sudoriferous glands are commonly known as sweat glands and are responsible for producing perspiration to regulate body temperature. Ceruminous glands produce earwax, sebaceous glands produce sebum (oil), and 'Integumentary' refers to the integumentary system, which includes the skin, hair, and nails. Choice A, Ceruminous glands, are responsible for producing earwax, not sweat. Choice B, Sebaceous glands, produce sebum (oil) to lubricate the skin and hair. Choice D, Integumentary, refers to the integumentary system, not a specific type of gland.