Nursing Elites

1. Which of the following molecules is a monosaccharide?

• A. Starch
• B. Glucose
• C. Cellulose
• D. Sucrose

Correct answer: B

Rationale: Starch is a polysaccharide, not a monosaccharide, making choice A incorrect. Glucose, choice B, is the correct answer as it is a monosaccharide, the simplest form of sugar. Cellulose, choice C, is a polysaccharide like starch, not a monosaccharide. Sucrose, choice D, is a disaccharide composed of glucose and fructose, not a monosaccharide. Glucose, being a monosaccharide, is a single sugar unit that serves as a primary energy source for living organisms.

2. Which of the following is specialized tissue in the right atrium that acts as the heart’s natural pacemaker by generating the electrical signal for the heartbeat?

• A. sinus venosus
• B. sinoatrial node
• C. atrioventricular node
• D. tricuspid valve

Correct answer: B

Rationale: The sinoatrial node, often referred to as the SA node, is specialized tissue located in the right atrium of the heart. It functions as the heart's natural pacemaker by generating the electrical signal that initiates each heartbeat. This electrical signal spreads to the atrial muscles and then to the atrioventricular node, causing the heart to contract rhythmically and efficiently. The other options listed do not serve as the heart's natural pacemaker responsible for generating the electrical signal for the heartbeat. Sinus venosus is a developmental structure in fetal hearts, the atrioventricular node delays the electrical signal, and the tricuspid valve is a heart valve that prevents backflow of blood from the right ventricle to the right atrium.

3. Which organelle is responsible for carrying out photosynthesis in plant cells?

• A. Golgi apparatus
• B. Mitochondria
• C. Chloroplasts
• D. Lysosomes

Correct answer: C

Rationale: A) Golgi apparatus: The Golgi apparatus is responsible for modifying, sorting, and packaging proteins for secretion or for use within the cell. It is not involved in photosynthesis. B) Mitochondria: Mitochondria are known as the powerhouse of the cell and are responsible for generating energy in the form of ATP through cellular respiration. They are not involved in photosynthesis. C) Chloroplasts: Chloroplasts are the organelles responsible for carrying out photosynthesis in plant cells. They contain chlorophyll, a pigment that captures light energy and converts it into chemical energy in the form of glucose. D) Lysosomes: Lysosomes are membrane-bound organelles that contain digestive enzymes to break down waste materials and cellular debris. They are not involved in photosynthesis. Therefore, the correct answer is C) Chloroplasts, as they are specifically responsible for carrying out photosynthesis in plant

4. What are the three layers of the skin?

• A. Epidermis, dermis, subdermis
• B. Epidermis, dermis, hypodermis
• C. Dermis, subdermis, hypodermis
• D. Epidermis, dermis, adipose layer

Correct answer: B

Rationale: The correct answer is B: Epidermis, dermis, hypodermis. The three layers of the skin are the epidermis (outer layer), dermis (middle layer), and hypodermis (inner layer of fat and connective tissue). The hypodermis is also known as the subcutaneous tissue and is primarily composed of adipose (fat) tissue, providing insulation and padding to the body. Choice A is incorrect as 'subdermis' is not a recognized layer of the skin. Choice C is incorrect as 'dermis' is the middle layer, not the outer layer. Choice D is incorrect as the layer below the dermis is the hypodermis, not specifically an 'adipose layer.'

5. What is the difference between homologous chromosomes and sister chromatids?

• A. Homologous chromosomes have the same genes but may have different alleles, while sister chromatids are identical copies of the same chromosome.
• B. Homologous chromosomes are only found in diploid cells, while sister chromatids are found in both haploid and diploid cells.
• C. Both homologous chromosomes and sister chromatids are genetically identical, but only sister chromatids separate during mitosis.
• D. Both homologous chromosomes and sister chromatids can separate during mitosis, but only homologous chromosomes have different alleles.

Correct answer: A

Rationale: Rationale: - Homologous chromosomes are pairs of chromosomes that have the same genes in the same order, one from each parent. While they carry the same genes, they may have different alleles (variants of a gene). - Sister chromatids are exact copies of each other, formed during DNA replication. They are held together by a centromere and are produced during the S phase of the cell cycle. - During meiosis, homologous chromosomes pair up and exchange genetic material through crossing over, leading to genetic variation. Sister chromatids separate during mitosis to ensure each daughter cell receives an identical copy of the genetic material.

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