Biology

Individuals with the AB+ blood group are considered universal recipients because they have all A, B, and Rh antigens, allowing them to receive red blood cells from any blood type without immune reaction.

Addison's disease, also known as primary adrenal insufficiency, is caused by the failure of the adrenal glands to produce sufficient hormones, primarily cortisol and aldosterone. This failure is most commonly due to autoimmune destruction of the adrenal cortex. The pituitary gland produces adrenocorticotrophic hormone (ACTH), which stimulates the adrenal glands to produce these hormones. In Addison's disease, the adrenal glands fail despite normal or elevated ACTH levels. Therefore, the disease is caused by adrenal hormone deficiency, not ACTH deficiency. However, among the given options, ACTH (option D) is the hormone most closely related to adrenal function regulation. The other options (Antidiuretic Hormone, Luteinising Hormone, Melanophore Stimulating Hormone) are unrelated to Addison's disease. Hence, option D is the best choice given the options, but it should be understood that Addison's disease results from adrenal gland hormone deficiency, not ACTH deficiency.

At night, photosynthesis stops because there is no sunlight, so plants do not produce oxygen. However, they continue to respire, taking in oxygen and giving off carbon dioxide, just like animals.

Hummingbirds are warm-blooded animals that regulate their own body temperature internally, which classifies them as endotherms. This means they generate heat metabolically rather than relying on external sources.

Eugenics is the study and practice of improving the genetic quality of the human population by selective breeding or genetic intervention, which aligns with option A.

The average adult human has a blood volume of about 5 to 6 liters, with 6 liters being a commonly accepted average for a typical adult. Therefore, option C (6 liters) is the most accurate choice.

White blood cells (WBCs) generally have a lifespan ranging from 1 to 5 days, depending on the type. Some WBCs may live longer, but the typical range is 1-5 days, making option A the most accurate.

The average lifespan of red blood cells in the human body is approximately 120 days before they are broken down and recycled by the spleen and liver.

Lycopene is the pigment responsible for the red color inside a watermelon. It is a red carotenoid pigment found in various red fruits and vegetables, including tomatoes and watermelons.

Darwinism is based on natural selection, overproduction, and competition for survival. Inheritance of acquired characters is a Lamarckian concept, not part of Darwin's theory.