what is the acceleration due to gravity near the earths surface

ATI TEAS 7

ati teas 7 science

1. What is the acceleration due to gravity near the Earth's surface?

A. 9.8 meters per second squared (m/sÂ²)
B. 6.3 meters per second squared (m/sÂ²)
C. 5.0 meters per second squared (m/sÂ²)
D. 12.5 meters per second squared (m/sÂ²)

Correct answer: A

Rationale: The acceleration due to gravity near the Earth's surface is approximately 9.8 m/sÂ². This value is commonly used in physics calculations and represents the rate at which an object accelerates towards the Earth when in free fall. The acceleration due to gravity is a constant value near the Earth's surface and affects the motion of all objects. Choices B, C, and D are incorrect as they do not represent the standard value of 9.8 m/sÂ². Understanding the correct value of acceleration due to gravity is fundamental in physics as it helps in solving various problems related to motion, forces, and energy.

2. The neutral theory of molecular evolution proposes that:

A. Most mutations in DNA are selectively neutral and do not affect an organism's fitness.
B. All mutations are beneficial and contribute to the adaptation of a population.
C. The rate of evolution is primarily driven by strong directional selection pressures.
D. Genetic drift plays a negligible role in shaping genetic variation within populations.

Correct answer: A

Rationale: Rationale: A) The neutral theory of molecular evolution, proposed by Motoo Kimura in the 1960s, suggests that the majority of mutations that occur in DNA are selectively neutral, meaning they do not have a significant impact on an organism's fitness. These neutral mutations are not subject to natural selection and are allowed to accumulate in populations over time. This theory helps explain the high levels of genetic variation observed within populations. B) Option B is incorrect because not all mutations are beneficial. Mutations can be neutral, harmful, or beneficial, and the neutral theory specifically focuses on the idea that many mutations are neutral in their effects. C) Option C is incorrect because the neutral theory suggests that evolution is not primarily driven by strong directional selection pressures. Instead, it emphasizes the role of genetic drift and the accumulation of neutral mutations in shaping genetic variation. D) Option D is incorrect because

3. Which bone is the longest in the human body?

A. Femur (Thigh bone)
B. Humerus (Upper arm bone)
C. Tibia (Shin bone)
D. Scapula (Shoulder blade)

Correct answer: A

Rationale: The correct answer is the femur (thigh bone) as it is the longest bone in the human body, extending from the hip to the knee. It plays a vital role in supporting the body's weight and enabling movement. The humerus is located in the upper arm and is not as long as the femur. The tibia is the shin bone and is shorter than the femur. The scapula is the shoulder blade and is not the longest bone in the body, making it an incorrect choice.

4. The liver plays a vital role in digestion. What is one of the main functions of the liver in the digestive system?

A. Physical breakdown of food
B. Production of digestive enzymes
C. Storage and processing of nutrients
D. Elimination of waste products

Correct answer: C

Rationale: The correct answer is C: Storage and processing of nutrients. The liver plays a crucial role in processing nutrients absorbed from the small intestine, storing glycogen, vitamins, and minerals, and regulating blood sugar levels by releasing or storing glucose as needed. Choices A, B, and D are incorrect because the physical breakdown of food primarily occurs in the mouth and stomach, the production of digestive enzymes is mainly carried out by the pancreas and small intestine, and the elimination of waste products is primarily managed by the large intestine and kidneys, not the liver.

5. Which hormone stimulates the release of calcium from bones and increases blood calcium levels?

A. Parathyroid hormone (PTH)
B. Calcitonin
C. Growth hormone
D. Testosterone

Correct answer: A

Rationale: Parathyroid hormone (PTH) is the correct answer. PTH stimulates the release of calcium from bones, leading to increased blood calcium levels. It acts on the bones to release calcium into the bloodstream, facilitates the kidneys' reabsorption of calcium, and triggers vitamin D activation to boost calcium absorption from the intestines. Choice B, Calcitonin, is incorrect as it works in opposition to PTH by decreasing blood calcium levels through inhibiting calcium release from bones. Choices C and D, Growth hormone and Testosterone, are not directly involved in calcium homeostasis and do not regulate blood calcium levels through bone calcium release mechanisms.