During the depolarization phase of an action potential, there is a rapid influx of: MCQ with Answer and Explanation

Explanation:
Mammals are distinguished by the presence of mammary glands in females that secrete milk for nourishing young. They are warm-blooded, have hair/fur, and most give birth to live young (viviparous), though monotremes like platypus lay eggs. Feathers are characteristic of birds. Cold-blooded refers to ectotherms (reptiles, amphibians, fish). Mammals are endotherms.

Explanation:
Albinism is a genetic disorder due to a defect in tyrosinase enzyme, leading to little or no melanin production, affecting skin, hair, and eye color. Vitiligo is patchy loss of melanocytes, jaundice is yellowing from bilirubin, erythema is redness. Albinism results in extreme sensitivity to sunlight.

Explanation:
Black stem rust of wheat is caused by the fungus Puccinia graminis tritici, a basidiomycete that produces reddish-brown uredospores and black teliospores. It requires barberry as an alternate host. It is a major disease causing significant crop losses.