the largest bone in the human body is the

ATI TEAS 7

ati teas 7 science

1. What is the largest bone in the human body?

A. Femur (thigh bone)
B. Tibia (shin bone)
C. Humerus (upper arm bone)
D. Scapula (shoulder blade)

Correct answer: A

Rationale: The femur, also known as the thigh bone, holds the title of the largest bone in the human body. Situated in the upper leg, the femur plays a vital role in supporting the body's weight and enabling movement. While the tibia (shin bone), humerus (upper arm bone), and scapula (shoulder blade) are all essential bones, none of them match the femur in terms of size and importance. The tibia, humerus, and scapula are comparatively smaller bones with specific functions in their respective areas of the body, but they do not surpass the femur in size or significance.

2. Which of the following nucleic acids carries amino acids to organelles called ribosomes, where the amino acids are linked one by one to produce a polypeptide?

A. DNA
B. mRNA
C. rRNA
D. tRNA

Correct answer: D

Rationale: tRNA is the correct answer as it carries amino acids to the ribosomes during protein synthesis. Transfer RNA (tRNA) plays a crucial role in protein synthesis by bringing specific amino acids to the ribosome according to the mRNA sequence. Once at the ribosome, the amino acids are linked together to form a polypeptide chain. This process is essential for the creation of proteins in the cell, highlighting the significance of tRNA in the translation process. Choice A, DNA, is incorrect as DNA does not directly participate in protein synthesis. Choice B, mRNA, is incorrect as mRNA carries the genetic information from DNA to the ribosome but does not directly carry amino acids. Choice C, rRNA, is incorrect as ribosomal RNA is a component of the ribosome structure and is involved in protein synthesis but does not carry amino acids like tRNA.

3. Which organ in the human body is the largest and is responsible for detoxification, metabolism, and storage of nutrients?

A. Heart
B. Liver
C. Lungs
D. Skin

Correct answer: B

Rationale: The liver is the largest internal organ in the human body and is responsible for detoxification, metabolism, storage of nutrients, and various other essential functions. It plays a critical role in maintaining overall health by processing nutrients, filtering blood, and detoxifying harmful substances. While the skin is the largest organ by surface area, the liver is the largest internal organ and is crucial for various physiological processes. The heart is responsible for pumping blood, the lungs for respiration, and the skin for protection and temperature regulation, but they do not perform the functions specified in the question.

4. Which of the following describes the general function of cytokines in the immune system?

A. They communicate between cells to instigate an immune response.
B. They inhibit blood clotting during inflammation responses.
C. They bind to specific pathogens to increase pathogen mass.
D. They transport pathogens trapped in mucus to be destroyed in the stomach.

Correct answer: A

Rationale: The correct answer is A: 'They communicate between cells to instigate an immune response.' Cytokines are signaling molecules that act as messengers between cells in the immune system, playing a vital role in coordinating and regulating immune responses. They communicate with various immune cells to initiate appropriate responses against pathogens. Choice B is incorrect because cytokines do not inhibit blood clotting but rather regulate immune responses. Choice C is incorrect as cytokines do not bind to specific pathogens to increase their mass; instead, they regulate the immune response. Choice D is also incorrect because cytokines do not transport pathogens trapped in mucus to the stomach for destruction; they primarily function as signaling molecules within the immune system.

5. What is the process by which a cell divides into two or more new cells?

A. Mitosis
B. Meiosis
C. Both mitosis and meiosis
D. None of the above

Correct answer: A

Rationale: Mitosis is the process by which a cell divides into two identical daughter cells. This type of cell division is essential for growth, repair, and maintenance of multicellular organisms. Meiosis, on the other hand, is a type of cell division that produces gametes (sperm and egg cells) with half the number of chromosomes as the parent cell. Meiosis does not directly result in the formation of new cells, as it is specifically geared towards the production of reproductive cells. Therefore, the correct answer is A. Option C, stating both mitosis and meiosis, is incorrect because meiosis is not involved in the general process of cell division to produce new cells; it is specialized for gamete formation. Option D is incorrect because mitosis is indeed the process responsible for cell division in which one cell divides into two daughter cells, making it the accurate choice for this question.