Nokea
What is the name for the hard, protective protein that makes up hair and nails?
- A. Collagen
- B. Keratin
- C. Elastin
- D. Fibrin
Correct Answer: B
Rationale: Keratin is the correct answer as it is the hard, protective protein that comprises hair and nails. Collagen is a different type of protein found in connective tissues, providing structure and support. Elastin imparts elasticity to tissues, allowing them to stretch and recoil. Fibrin is a protein involved in the blood clotting process and is not related to the structure of hair and nails. Therefore, choices A, C, and D are incorrect in the context of the question.
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Where is pseudostratified columnar epithelium primarily found?
- A. Skeletal muscle
- B. Bony skeleton
- C. External ears
- D. Bloodstream
Correct Answer: C
Rationale: Pseudostratified columnar epithelium is a type of epithelial tissue found in the respiratory tract, including the lining of the trachea and bronchi. It is also found in the male reproductive system and parts of the auditory tube and external ear canal. Among the options provided, the external ears (option C) are the most relevant location for pseudostratified columnar epithelium. Skeletal muscle (option A) is primarily composed of muscle fibers, not epithelial tissue. The bony skeleton (option B) is composed of bone tissue. The bloodstream (option D) consists of blood cells and plasma, not epithelial tissue.
Which of the following is the main organ responsible for storing energy?
- A. Liver
- B. Heart
- C. Kidneys
- D. Adipose tissue
Correct Answer: D
Rationale: Adipose tissue, commonly known as body fat, is the main organ responsible for storing energy in the form of triglycerides. It serves as a reserve of energy that can be utilized when needed. The liver primarily regulates glucose levels and stores glycogen for short-term energy needs but is not the main organ for long-term energy storage. The heart's main function is to pump blood throughout the body and is not involved in energy storage. The kidneys are essential for filtering blood and maintaining fluid balance but are not responsible for storing energy.
What is the process by which genetic information is used to produce proteins?
- A. Replication
- B. Transcription
- C. Translation
- D. Mutation
Correct Answer: C
Rationale: A) Replication is the process by which DNA is copied to produce an identical strand of DNA. This process occurs during cell division to ensure that each daughter cell receives a complete set of genetic information.
B) Transcription is the process by which genetic information from DNA is copied into a complementary RNA molecule. This RNA molecule, known as messenger RNA (mRNA), serves as a template for protein synthesis during translation.
C) Translation is the process by which the genetic information carried by mRNA is decoded to produce a specific sequence of amino acids, which are then assembled into a protein. This process occurs at the ribosomes in the cytoplasm of the cell.
D) Mutation refers to a change in the DNA sequence that can result in alterations to the genetic information. Mutations can occur spontaneously or be induced by external factors such as radiation or chemicals. While mutations can impact protein synthesis, they are not the process by which genetic inf
After exposure to a pathogen, the immune system develops memory. What type of immune cell is responsible for this immunological memory?
- A. B cells
- B. T cells (specifically memory T cells)
- C. Phagocytes
- D. Natural killer cells
Correct Answer: A
Rationale: B cells are responsible for immunological memory. Memory B cells, a type of B cells, retain a 'memory' of specific pathogens, enabling them to rapidly produce antibodies upon re-exposure. This rapid antibody production facilitates a quicker and more effective immune response. Although memory T cells also contribute to immunological memory by mounting a swift and robust immune response upon re-exposure to the pathogen, it is primarily memory B cells that play a crucial role in producing antibodies. Phagocytes are important immune cells involved in engulfing and digesting pathogens, while natural killer cells are primarily responsible for recognizing and eliminating abnormal cells, such as virus-infected cells or tumor cells. However, when it comes to immunological memory and antibody production, B cells are key players.
Which hormone, produced by the pituitary gland, stimulates the growth and development of bones, muscles, and organs?
- A. Growth hormone (GH)
- B. Thyroid-stimulating hormone (TSH)
- C. Prolactin
- D. Follicle-stimulating hormone (FSH)
Correct Answer: A
Rationale: The correct answer is Growth hormone (GH). GH, produced by the pituitary gland, is responsible for stimulating the growth and development of bones, muscles, and organs. It plays a critical role in regulating growth during childhood and adolescence by promoting cell division, protein synthesis, and tissue growth. Thyroid-stimulating hormone (TSH) functions to stimulate the thyroid gland to produce thyroid hormones, while prolactin is involved in milk production. Follicle-stimulating hormone (FSH) is primarily responsible for reproductive functions like egg development in females and sperm production in males.