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 ethical concern surrounding genetic engineering?

A. Risk of introducing new diseases
B. Potential for misuse and discrimination
C. Unforeseen consequences on ecosystems
D. All of the above

Correct answer: D

Rationale: A) Risk of introducing new diseases: Genetic engineering involves manipulating the genetic material of organisms, which can potentially lead to the creation of new diseases or the spread of existing ones in unintended ways. This risk raises ethical concerns about the potential harm to human health and the environment. B) Potential for misuse and discrimination: Genetic engineering technologies can be misused for purposes such as creating biological weapons or enhancing certain traits in individuals, leading to discrimination based on genetic makeup. This raises ethical concerns about fairness, justice, and the potential for societal harm. C) Unforeseen consequences on ecosystems: Genetic engineering can have unintended consequences on ecosystems, such as disrupting natural balances or harming biodiversity. These unforeseen impacts raise ethical concerns about the responsibility of scientists and policymakers to consider the long-term effects of genetic modifications on the environment. Therefore, the correct answer is D because all the options present valid ethical concerns associated with genetic engineering.

3. What function do genes serve in the relationship between parents and offspring?

A. Genes enable hereditary information to be passed from parents to offspring.
B. Genes prohibit hereditary information from being passed from parents to offspring.
C. Genes enable environmental factors to affect parents and offspring.
D. Genes serve no function in the relationship between parents and offspring.

Correct answer: A

Rationale: Genes play a crucial role in passing hereditary information from parents to offspring, ensuring the transmission of genetic traits. This process forms the basis of inheritance and genetic continuity between generations. Choice B is incorrect as genes do not prohibit but rather facilitate the transmission of hereditary information. Choice C is incorrect because genes primarily transmit genetic information, while the influence of environmental factors is separate. Choice D is incorrect as genes are fundamental in genetic inheritance and the relationship between parents and offspring.

4. Which lifestyle practice can weaken the immune system?

A. Getting enough sleep
B. Eating a balanced diet rich in fruits and vegetables
C. Managing stress levels
D. Frequent smoking

Correct answer: D

Rationale: Frequent smoking can weaken the immune system by damaging immune cells and impairing their function. Smoking increases the risk of respiratory infections and other illnesses, negatively impacting immune health. Therefore, frequent smoking is a lifestyle practice that can weaken the immune system. Choices A, B, and C are all beneficial practices that support a healthy immune system. Getting enough sleep, eating a balanced diet rich in fruits and vegetables, and managing stress levels are important for maintaining optimal immune function and overall well-being.

5. Which valve allows blood flow from the right atrium into the right ventricle?

A. Tricuspid valve
B. Pulmonic valve
C. Mitral valve
D. Aortic valve

Correct answer: A

Rationale: The correct answer is the Tricuspid valve. This valve is located between the right atrium and the right ventricle in the heart. Its primary function is to facilitate the flow of blood from the right atrium into the right ventricle and to prevent the backflow of blood. The Pulmonic valve (choice B) is situated between the right ventricle and the pulmonary artery, not between the right atrium and ventricle, making it incorrect. The Mitral valve (choice C) is found between the left atrium and the left ventricle, not the right side, so it is incorrect. The Aortic valve (choice D) is positioned between the left ventricle and the aorta, not involved in the right atrium and ventricle connection, hence it is also incorrect.