ati teas 7 science

Correct Answer: B

Rationale: The correct answer is B because "survival of the fittest" refers to the idea that organisms with the best adaptations to their environment are more likely to survive and reproduce, passing on their advantageous traits to the next generation. This concept, coined by Charles Darwin, emphasizes the importance of natural selection in driving evolution. Choice A is incorrect as complexity does not always equate to fitness. Choice C is incorrect as natural selection favors certain traits over others. Choice D is incorrect as survival and reproduction are not solely determined by strength and aggression.

Correct Answer: D

Rationale: The correct answer is D, the medium's properties. The speed of a wave in a given medium is determined by the properties of that medium, such as its density and elasticity. This affects how fast the wave can travel through the medium. Amplitude (A) is the height of a wave, which does not directly impact the speed of the wave. Wavelength (B) is the distance between two consecutive points of a wave, and while it can affect the wave's behavior, it does not solely determine its speed. Frequency (C) is the number of wave cycles that pass a point in a given time, which is related to speed but not the sole determinant. Therefore, the correct answer is D as the properties of the medium directly influence the speed of the wave.

Correct Answer: A

Rationale: The correct answer is A: Calcitonin. Calcitonin is produced by the thyroid gland and functions to lower blood calcium levels by promoting calcium deposition in bones and inhibiting calcium reabsorption in the kidneys. This hormone opposes the action of parathyroid hormone (PTH), which increases blood calcium levels by promoting calcium release from bones and increasing calcium reabsorption in the kidneys. Thyroxine is a thyroid hormone that regulates metabolism and growth, not calcium levels. Insulin is a hormone produced by the pancreas that regulates blood sugar levels, not calcium levels. Thus, A is the correct answer as it directly regulates calcium levels in the blood through its actions on bones and kidneys.

Correct Answer: A

Rationale: The correct answer is A: Group 1. Alkali metals are located in Group 1 of the periodic table because they have one electron in their outermost shell, making them highly reactive. These elements include lithium, sodium, potassium, and others. Group 2 (Choice B) consists of alkaline earth metals, Group 7 (Choice C) consists of halogens, and Group 8 (Choice D) consists of noble gases. Alkali metals exhibit unique properties due to their single valence electron, distinguishing them from elements in the other groups mentioned.

Correct Answer: A

Rationale: The correct answer is A: Hypothalamus. The hypothalamus plays a vital role in regulating body temperature by responding to internal and external temperature changes. It coordinates the body's response to maintain a stable temperature through processes like sweating or shivering. B: Cerebellum is responsible for coordinating movement and balance, not body temperature regulation. C: Pituitary gland regulates hormone production but not directly involved in body temperature regulation. D: Thyroid gland controls metabolism and energy levels but not primarily responsible for regulating body temperature.