Nokea
Which of the following structures in the body is responsible for protecting the lungs and heart?
- A. Rib cage
- B. Pelvis
- C. Femur
- D. Vertebral column
Correct Answer: A
Rationale: The rib cage is the correct answer. It plays a crucial role in protecting vital organs like the lungs and heart. The rib cage forms a protective barrier around these organs, shielding them from external trauma or injuries. It acts as a sturdy cage, offering structural support and safeguarding the delicate tissues and structures of the lungs and heart. The pelvis, femur, and vertebral column do not directly protect the lungs and heart; instead, they have other important functions in the body, such as supporting the body's weight, enabling movement, and protecting the spinal cord.
You may also like to solve these questions
What cells compose the epidermis?
- A. Keratinocytes
- B. Epithelial cells
- C. Fibroblasts
- D. Melanocytes
Correct Answer: A
Rationale: The correct answer is A - Keratinocytes. The epidermis is primarily composed of keratinocytes, which are a type of epithelial cell. Keratinocytes synthesize the protein keratin, providing protection against physical damage and water loss. While epithelial cells are correct, specifying keratinocytes is more precise. Fibroblasts are not the main cell type in the epidermis; they are found in the dermis, where they produce collagen and other extracellular matrix components. Melanocytes are responsible for producing melanin pigment in the skin and are also present in the epidermis, but they are not the predominant cell type like keratinocytes.
Which organelle is responsible for producing energy in the cell?
- A. Nucleus
- B. Mitochondria
- C. Golgi apparatus
- D. Ribosome
Correct Answer: B
Rationale: The correct answer is B: Mitochondria. Mitochondria are known as the powerhouse of the cell and are responsible for producing energy in the form of ATP through the process of cellular respiration. The other organelles listed, such as the nucleus, Golgi apparatus, and ribosome, have different functions within the cell and are not directly involved in energy production. The nucleus is responsible for storing genetic material and controlling cell activities. The Golgi apparatus is involved in modifying, sorting, and packaging proteins. Ribosomes are responsible for protein synthesis.
Which valve prevents the backflow of blood into the left ventricle as it leaves through the aorta?
- A. Pulmonary semilunar valve
- B. Aortic semilunar valve
- C. Tricuspid valve
- D. Mitral valve
Correct Answer: B
Rationale: The aortic semilunar valve is the correct answer as it prevents the backflow of blood into the left ventricle once it has been pumped into the aorta. The pulmonary semilunar valve prevents backflow into the right ventricle, the tricuspid valve controls blood flow between the right atrium and ventricle, and the mitral valve regulates blood flow between the left atrium and ventricle. Therefore, option B is the correct choice for this question.
What is a monohybrid cross, and what is the ratio of dominant to recessive gene manifestation?
- A. A cross involving two traits, 9:3:3:1
- B. A cross involving one trait, 3:1
- C. A cross involving two traits, 1:2:1
- D. A cross involving one trait, 1:1
Correct Answer: B
Rationale: A monohybrid cross is a genetic cross involving one trait. The ratio of dominant to recessive gene manifestation in the offspring is typically 3:1 when both parents are heterozygous. This ratio is the genotypic ratio, not just the phenotype ratio, where the dominant allele is present in 3 out of 4 offspring, and the recessive allele is present in 1 out of 4 offspring. Choice A is incorrect because it describes a dihybrid cross ratio. Choice C is incorrect as it represents the genotypic ratio for a monohybrid cross involving incomplete dominance. Choice D is incorrect as it does not reflect the typical ratio for a monohybrid cross.
What is the main function of the skeletal system?
- A. To regulate blood pressure
- B. To protect internal organs
- C. To produce hormones
- D. To fight infection
Correct Answer: B
Rationale: The main function of the skeletal system is to provide structural support for the body, protect internal organs, facilitate movement, and produce blood cells in the bone marrow. Choice A, 'To regulate blood pressure,' is incorrect as blood pressure regulation is primarily controlled by the circulatory and endocrine systems. Choice C, 'To produce hormones,' is incorrect as hormone production is mainly carried out by the endocrine system. Choice D, 'To fight infection,' is incorrect as the immune system is responsible for fighting infections, not the skeletal system.