Nursing Elites

1. Which hormones are responsible for stimulating the development of sex organs and secondary sex characteristics during puberty?

• A. Growth hormone
• B. Testosterone (in males) and Estrogen (in females)
• C. Insulin
• D. Thyroid hormone

Correct answer: B

Rationale: Testosterone and estrogen are the primary sex hormones responsible for the development of male and female sex organs, respectively, and the emergence of secondary sex characteristics during puberty. Growth hormone, insulin, and thyroid hormone do not directly influence the development of sex organs and secondary sex characteristics during puberty. Growth hormone primarily regulates growth and metabolism, insulin regulates blood sugar levels, and thyroid hormone controls metabolism and energy levels. Therefore, choices A, C, and D are incorrect for this question.

2. Which organelle is responsible for packaging and secreting proteins into the extracellular space?

• A. Golgi apparatus
• B. Mitochondria
• C. Ribosomes
• D. Endoplasmic reticulum

Correct answer: A

Rationale: A) Golgi apparatus: The Golgi apparatus is responsible for modifying, sorting, and packaging proteins into vesicles for secretion outside the cell or for use within the cell. It acts as a distribution and shipping department for the cell, ensuring proteins are properly processed and sent to their correct destinations like the extracellular space. Golgi apparatus is the correct answer because it directly handles the packaging and secretion of proteins. 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 packaging and secreting proteins into the extracellular space. C) Ribosomes: Ribosomes are responsible for protein synthesis, where they translate mRNA into proteins. They are not involved in packaging and secreting proteins into the extracellular space. D) Endoplasmic reticulum: The endoplasmic reticulum (ER) plays a role in protein synthesis and folding, but it is the rough ER specifically that is involved in synthesizing proteins that are then transported to the Golgi apparatus for further processing and packaging. The Golgi apparatus is primarily responsible for packaging and secreting proteins, making it the correct answer for this question.

3. What tool helps scientists identify and classify organisms based on their shared characteristics?

• A. Binomial nomenclature
• B. Cladistics
• C. Dichotomous key
• D. Domain-based classification

Correct answer: C

Rationale: A) Binomial nomenclature is a system used to give each organism a two-part scientific name (genus and species) but does not help in identifying or classifying organisms based on shared characteristics. B) Cladistics is a method of classification based on evolutionary relationships and shared characteristics, but it is not a tool used for identifying organisms. C) A dichotomous key is a tool that helps scientists identify and classify organisms based on their shared characteristics by presenting a series of choices leading the user to the correct identification. D) Domain-based classification is a system of grouping organisms into three domains (Bacteria, Archaea, Eukarya) based on molecular and genetic similarities, but it is not a tool used for identifying organisms based on shared characteristics.

4. What is the difference between a pure substance and a mixture?

• A. Pure substances have a fixed composition, mixtures don't.
• B. Mixtures have a fixed composition, pure substances don't.
• C. Pure substances can be in any state, mixtures are not always solids.
• D. Pure substances are always elements, mixtures are always compounds.

Correct answer: A

Rationale: Pure substances have a definite and constant composition, meaning they are made up of only one type of atom or molecule with fixed proportions. This composition does not vary. On the other hand, mixtures are composed of two or more substances physically combined. The components of a mixture can be present in varying proportions, leading to a variable composition. Choice A is correct as it accurately distinguishes between pure substances and mixtures based on the fixed composition of pure substances and the variable composition of mixtures. Choice B is incorrect because mixtures, not pure substances, have variable compositions. Choice C is incorrect as both pure substances and mixtures can exist in different states. Choice D is incorrect because pure substances can be compounds as well, not exclusively elements, and mixtures can contain elements and compounds.

5. How does the structure of centromeres contribute to chromosome movement during mitosis?

• A. The centromere provides a binding site for spindle fibers, allowing chromosomes to be attached and manipulated.
• B. The centromere serves as a dividing point between sister chromatids, ensuring their separation during anaphase.
• C. The centromere maintains chromosome stability by preventing chromosomal breaks and rearrangements.
• D. The centromere plays a role in DNA replication, ensuring accurate copying of the genetic material.

Correct answer: A

Rationale: A) The centromere provides a binding site for spindle fibers, which are microtubules that help move chromosomes during cell division. This attachment allows the chromosomes to be pulled towards opposite poles of the cell during mitosis. Therefore, the structure of centromeres directly contributes to chromosome movement during mitosis by facilitating the attachment and manipulation of chromosomes by the spindle fibers. B) While the centromere does serve as a dividing point between sister chromatids, ensuring their separation during anaphase, this function is more related to the segregation of chromosomes rather than their movement. C) The centromere does play a role in maintaining chromosome stability by ensuring proper chromosome segregation, but it is not primarily responsible for preventing chromosomal breaks and rearrangements. D) The centromere is not directly involved in DNA replication. Its main function is

Similar Questions