Nursing Elites

1. What is the independent variable in the botanist's experiment?

• A. Temperature
• B. Root tissue
• C. Light exposure
• D. Root length

Correct answer: A

Rationale: In an experiment, the independent variable is the factor that is deliberately manipulated or changed by the researcher. The botanist is likely altering the temperature to observe its effect on the plants. Therefore, temperature is the independent variable in the botanist's experiment. Choice B, root tissue, is not the independent variable as it is not the factor being intentionally changed in the experiment. Choice C, light exposure, and choice D, root length, are also not the independent variables as they are not the factors being purposely manipulated by the researcher in this scenario.

2. What is the formula to calculate gravitational potential energy near the Earth's surface?

• A. Potential Energy = Mass × Acceleration
• B. Potential Energy = Force × Distance
• C. Potential Energy = Mass × Height × Gravity
• D. Potential Energy = Mass × Acceleration due to gravity × Height

Correct answer: D

Rationale: The correct formula to calculate gravitational potential energy near the Earth's surface is Potential Energy = Mass × Acceleration due to gravity × Height. This formula considers the mass of the object, the specific acceleration due to gravity near the Earth's surface (approximately 9.81 m/s^2), and the vertical distance from the reference point. Choice A is incorrect as it does not include height in the formula. Choice B is incorrect as it involves force instead of acceleration due to gravity. Choice C is incorrect as it multiplies mass, height, and gravity, missing the actual acceleration due to gravity term.

3. What is the muscular sac in the female body that nourishes and protects a developing fetus?

• A. Ovary
• B. Fallopian tube
• C. Uterus
• D. Vagina

Correct answer: C

Rationale: The correct answer is the uterus. The uterus is a muscular organ in the female body where a fertilized egg implants and grows into a fetus during pregnancy. It provides nourishment and protection to the developing fetus. The ovaries produce eggs, the fallopian tubes transport eggs from the ovaries to the uterus, and the vagina is the muscular tube that connects the uterus to the outside of the body for childbirth. Therefore, the roles of the ovary, fallopian tube, and vagina are not related to nourishing and protecting a developing fetus, making them incorrect choices.

4. Homologous structures are similar structures in different organisms that have a common evolutionary origin. An example is:

• A. Butterfly wings and bird wings (analogous structures with different origins)
• B. The arm of a human, the wing of a bat, and the flipper of a whale
• C. The eyes of an octopus and a human (convergent evolution with different origins)
• D. The stinger of a bee and the barb of a cactus (unrelated structures)

Correct answer: B

Rationale: Homologous structures are similar structures found in different organisms that share a common evolutionary origin. The arm of a human, the wing of a bat, and the flipper of a whale are all examples of homologous structures. Despite serving different functions, they share a common underlying structure due to their evolutionary relationship, evidencing a shared ancestry. These structures are modified over time to suit the specific needs of each species. Option A (Butterfly wings and bird wings) refers to analogous structures with different origins. Option C (The eyes of an octopus and a human) describes convergent evolution where traits evolve independently. Option D (The stinger of a bee and the barb of a cactus) are unrelated structures.

5. What is the oxidation state of carbon in CH4?

• A. +1
• B. -1
• C. +2
• D. -4

Correct answer: D

Rationale: In CH4 (methane), carbon is bonded to four hydrogen atoms. Hydrogen has an oxidation state of +1. Since the overall charge of CH4 is 0, the oxidation state of carbon must be -4 to balance the charges. Each hydrogen contributes an oxidation state of +1, resulting in a total of +4 from hydrogen atoms. To achieve a total oxidation state of 0 for the molecule, carbon must have an oxidation state of -4 to offset the contribution from hydrogen. Therefore, the correct answer is -4. Choices A, B, and C are incorrect: +1 is the oxidation state of hydrogen, -1 is not the oxidation state of carbon in methane, and +2 is not the correct oxidation state of carbon in CH4.

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