Nursing Elites

1. Four different groups of the same species of peas are grown and exposed to differing levels of sunlight, water, and fertilizer as documented in the table below. The data in the water and fertilizer columns indicate how many times the peas are watered or fertilized per week, respectively. Group 2 is the only group that withered. What is a reasonable explanation for this occurrence? Group Sunlight Water Fertilizer 1 partial sun 4 mL/hr 1 2 full sun 7 mL/hr 1 3 no sun 14 mL/hr 2 4 partial sun 3 mL/hr 2

• A. Insects gnawed away at the stem of the plant.
• B. The roots rotted due to poor drainage.
• C. The soil type had nutritional deficiencies.
• D. This species of peas does not thrive in full sunlight.

Correct answer: D

Rationale: Group 2, the only group that withered, was exposed to full sun. This suggests that the species of peas being studied does not thrive in full sunlight, leading to its deterioration compared to the other groups with different light exposures. Choices A, B, and C are not the correct explanations for the withering of Group 2. There is no mention of insects in the stem, poor drainage, or soil nutritional deficiencies in the scenario provided. The key factor that sets Group 2 apart from the others is the full sunlight exposure, indicating that the species of peas is not suited for such conditions.

2. How can a single gene mutation lead to multiple phenotypes depending on the organism?

• A. Pleiotropy describes the effect of one gene influencing multiple seemingly unrelated traits.
• B. Epigenetics involves environmental factors modifying gene expression without altering the DNA sequence.
• C. Genetic drift refers to random changes in allele frequencies within a population.
• D. Gene regulation controls the timing and level of gene expression within an organism.

Correct answer: A

Rationale: A single gene mutation can lead to multiple phenotypes through pleiotropy, where one gene influences diverse traits or functions in an organism. This phenomenon occurs when the mutated gene affects different biochemical pathways, developmental processes, or cellular functions, resulting in a cascade of downstream effects that manifest as a variety of phenotypic outcomes. Choice B, epigenetics, involves modifications in gene expression influenced by environmental factors without altering the DNA sequence, which is not directly related to the question about single gene mutations causing multiple phenotypes. Choice C, genetic drift, refers to random changes in allele frequencies within a population, which is unrelated to the impact of a single gene mutation on multiple phenotypes. Choice D, gene regulation, focuses on controlling the timing and level of gene expression within an organism, which is not directly addressing how a single gene mutation can lead to diverse phenotypes.

3. How many different types of tissue are there in the human body?

• A. 4
• B. 6
• C. 8
• D. 10

Correct answer: A

Rationale: The correct answer is A: 4. There are 4 types of tissues in the human body: epithelial, connective, muscle, and nervous. Epithelial tissue covers the body surfaces, connective tissue provides support and structure, muscle tissue enables movement, and nervous tissue transmits signals. Choices B, C, and D are incorrect as they do not represent the accurate number of tissue types found in the human body.

4. Which property of a substance refers to its ability to undergo a chemical change and form new substances?

• A. Density
• B. Mass
• C. Reactivity
• D. Volume

Correct answer: C

Rationale: Reactivity is the property of a substance that describes its ability to undergo a chemical change and form new substances through chemical reactions. Density, mass, and volume are physical properties of a substance and do not directly relate to its ability to undergo chemical changes. Density is the mass of a substance per unit volume, mass is the amount of matter present, and volume is the amount of space occupied by the substance. Reactivity specifically deals with how likely a substance is to engage in chemical reactions. Therefore, the correct answer is C - Reactivity.

5. Which gland in the endocrine system is responsible for the production of red blood cells?

• A. Pituitary gland
• B. Thyroid gland
• C. Thymus gland
• D. None of the above

Correct answer: D

Rationale: Red blood cells are not produced by any of the glands listed in the options. Instead, red blood cells are produced in the bone marrow. The pituitary gland is known as the 'master gland' and controls several other endocrine glands but is not responsible for red blood cell production. The thyroid gland regulates metabolism and growth, not red blood cell production. The thymus gland is responsible for the production of T-cells, which are a type of white blood cell involved in the immune response. The parathyroid gland regulates calcium levels in the body, not red blood cell production. Therefore, none of the glands listed are responsible for the production of red blood cells.

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