Which of the following describes the term allele?
- A. A specific form of a gene that can exist at a particular locus
- B. An inheritable variation of a gene
- C. A grouping of various genes
- D. Variations of complementary base pairs
Correct Answer: B
Rationale: The correct answer is B. Alleles are different forms of a gene that can exist at a specific locus. They represent variations of a gene and are inheritable. Choice A is incorrect as it does not fully capture the concept of an allele, which is a specific form of a gene rather than a substitution. Choice C is incorrect as alleles are not a grouping of various genes but rather different forms of a single gene at a specific locus. Choice D is also incorrect as it does not accurately describe alleles; alleles are variations of genes, not base pairs.
You may also like to solve these questions
Which of the following best describes a group of cells working together?
- A. Organelle
- B. Tissue
- C. Organ
- D. Organ system
Correct Answer: B
Rationale: The correct answer is B: Tissue. Tissue is a group of cells that work together to perform a specific function. Organelle refers to specialized structures within a cell, organ is a structure made up of different types of tissues working together, and organ system is a group of organs working together to perform complex functions. Therefore, tissue is the most appropriate term to describe a group of cells working together.
What is a primary function of red blood cells?
- A. To fight infection
- B. To carry oxygen
- C. To produce antibodies
- D. To transport waste
Correct Answer: B
Rationale: The main function of red blood cells is to carry oxygen from the lungs to all the body's tissues and organs, where it is needed for cellular functions and metabolism. This process is essential for sustaining life and providing energy to cells. Choice A is incorrect because fighting infection is primarily done by white blood cells. Choice C is incorrect because antibody production is mainly carried out by specialized white blood cells. Choice D is incorrect as the primary role of red blood cells is not to transport waste, but rather to transport oxygen and some carbon dioxide.
Which brain structure is responsible for processing visual information?
- A. Cerebrum
- B. Occipital lobe
- C. Frontal lobe
- D. Brainstem
Correct Answer: B
Rationale: The corrected question and choices are accurate. The correct answer is the Occipital lobe. The occipital lobe, located at the back of the brain, is primarily responsible for processing visual information received from the eyes. It plays a crucial role in interpreting and making sense of visual stimuli, allowing us to perceive and understand the world around us. The other choices, cerebrum (A), frontal lobe (C), and brainstem (D), do not have the primary function of processing visual information. The cerebrum is involved in higher brain functions, the frontal lobe is responsible for decision-making and personality, and the brainstem controls basic life functions like breathing and heart rate.
What type of tissue is found in the outermost layer of skin?
- A. Muscle tissue
- B. Connective tissue
- C. Epithelial tissue
- D. Nervous tissue
Correct Answer: C
Rationale: The correct answer is C: Epithelial tissue. Epithelial tissue forms the outermost layer of the skin, providing protection against external factors. It serves as a barrier and helps in preventing water loss and entry of pathogens into the body. Choice A, Muscle tissue, is incorrect as muscle tissue is responsible for movement, not skin structure. Choice B, Connective tissue, is incorrect as it provides support and structure to the body but is not the main component of the outermost layer of the skin. Choice D, Nervous tissue, is incorrect as nervous tissue is responsible for transmitting signals within the body, not for the outermost layer of the skin.
Which of the following neurotransmitters slows down the activity of neurons, preventing them from becoming overexcited?
- A. Acetylcholine
- B. Dopamine
- C. GABA
- D. Serotonin
Correct Answer: C
Rationale: The correct answer is C: GABA (gamma-aminobutyric acid). GABA acts as an inhibitory neurotransmitter that reduces neuronal activity, thus preventing overexcitation. Acetylcholine (choice A) is involved in muscle control and cognitive function, but it is not primarily responsible for slowing down neuronal activity. Dopamine (choice B) plays a role in reward-motivated behavior and motor control, rather than inhibiting neuronal firing. Serotonin (choice D) is involved in mood regulation, sleep, and appetite but does not primarily slow down neuronal activity to prevent overexcitation.