What is the process by which a cell divides to produce two daughter cells?

Correct Answer: A

Rationale: Mitosis is the correct answer because it is the process of cell division that results in the production of two daughter cells with identical genetic material to the parent cell. Meiosis, while also involving cell division, leads to the formation of gametes with half the number of chromosomes as the parent cell. Differentiation is the specialization of cells for specific functions, not the process of cell division. Transformation involves a cell incorporating foreign DNA into its genome, which is unrelated to the division of a cell into two daughter cells.

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.

Correct Answer: B

Rationale: Corticosteroids, produced by the adrenal cortex, primarily function to control blood pressure and electrolyte balance. One of the key corticosteroids, aldosterone, plays a crucial role in regulating sodium and potassium levels in the body. This regulation is essential for maintaining blood pressure and electrolyte balance. Choices A, C, and D are incorrect because corticosteroids do not primarily regulate insulin sensitivity and blood sugar levels, stimulate the immune system and inflammatory response, or promote growth and development during puberty. While corticosteroids can have effects on insulin sensitivity, immune response, and growth, their major role is in maintaining blood pressure and electrolyte balance.

Correct Answer: B

Rationale: The correct answer is B: Stratum corneum. The stratum corneum is the outermost layer of the epidermis, consisting of dead skin cells that are constantly shed and replaced. It serves as a protective barrier against pathogens and helps to prevent water loss from the body. Choice A, Stratum basale, is the deepest layer of the epidermis where new skin cells are produced. Choice C, Stratum granulosum, is a layer of the epidermis where the cells begin to flatten and lose their nuclei. Choice D, Stratum spinosum, is a layer of the epidermis where cells become irregular in shape and have spiny projections.

Correct Answer: A

Rationale: The patella, also known as the kneecap, is an example of a sesamoid bone. Sesamoid bones develop within tendons, such as the patellar tendon in this case. The patella is embedded in the tendon of the quadriceps muscle, enhancing the mechanical advantage of the muscle and protecting the knee joint. Long bones, like the femur, are characterized by their elongated shape with growth plates at the ends. Short bones, such as those in the wrist and ankle, are cube-shaped bones. Irregular bones, like vertebrae, do not fit into the other bone shape categories due to their unique shapes and functions.

Correct Answer: C

Rationale: Rationale: A) Carbon dioxide: Carbon dioxide is a greenhouse gas that is naturally present in the Earth's atmosphere and is also released through human activities such as burning fossil fuels. B) Water vapor: Water vapor is a greenhouse gas that is naturally present in the atmosphere and plays a significant role in the Earth's climate system. C) Nitrogen: Nitrogen is not considered a greenhouse gas because it does not have the ability to absorb and emit infrared radiation in the same way that greenhouse gases like carbon dioxide and methane do. D) Methane: Methane is a potent greenhouse gas that is released through natural processes such as wetland decomposition and human activities such as livestock farming and fossil fuel extraction. Therefore, the correct answer is C) Nitrogen, as it is not a greenhouse gas.

Correct Answer: C

Rationale: Thyroxine, also known as T4, is a hormone produced by the thyroid gland that plays a crucial role in regulating the body's metabolism, growth, and development. It helps control the rate at which the body uses energy, affects protein synthesis, and influences the body's sensitivity to other hormones. Calcitonin (A) is another hormone produced by the thyroid gland, but its primary function is to regulate calcium levels in the blood. Parathyroid hormone (PTH) (B) is produced by the parathyroid glands and is involved in regulating calcium and phosphorus levels in the body. Insulin (D) is a hormone produced by the pancreas that helps regulate blood sugar levels.

Correct Answer: C

Rationale: The main force propelling the rocket upwards is the thrust from the rocket engine. Thrust is the force produced by the rocket engine pushing exhaust gases in the opposite direction, following Newton's third law of motion (action and reaction). This thrust overcomes the force of gravity and allows the rocket to lift off and move upwards. Choice A, gravitational force, is incorrect as gravity pulls objects towards the Earth, and in this case, the rocket is moving against gravity. Choice B, air resistance, is incorrect because it opposes the motion of the rocket and is more relevant during descent rather than ascent. Choice D, normal force from the launchpad, is incorrect as this force acts perpendicular to the surface and does not propel the rocket upwards.

Correct Answer: D

Rationale: When light interacts with a perfectly smooth surface like a mirror, the dominant interaction is specular reflection. Specular reflection occurs when light rays are reflected off a smooth surface at the same angle as the incident angle, resulting in a clear and sharp reflection. Refraction, which involves the bending of light as it passes from one medium to another, is not the dominant interaction with a perfectly smooth surface. Diffraction, the bending of light waves around obstacles, is not the dominant interaction with smooth surfaces. Total internal reflection occurs when light is reflected back into a medium due to encountering a boundary at an angle greater than the critical angle, but it is not the dominant interaction on a perfectly smooth surface like a mirror.