Consider statements about human diseases: 1. Ascariasis is caused by a roundworm. 2. Ringworm is caused by a fungus. 3. Amoebiasis is caused by a bacterium. Which are correct? MCQ with Answer and Explanation

Explanation:
Dengue is transmitted by Aedes aegypti, which also spreads chikungunya, Zika, and yellow fever. Anopheles transmits malaria, Culex filariasis, tsetse sleeping sickness.

Explanation:
In plant tissue culture, when an explant (a piece of plant tissue) is placed on a nutrient medium containing specific plant hormones (like auxins and cytokinins), the cells dedifferentiate and undergo rapid, unorganized division to form a mass of cells called a callus. This callus is undifferentiated. Under appropriate hormonal conditions, this callus can then be induced to redifferentiate and form organized structures like shoots and roots (organogenesis) or somatic embryos.

Explanation:
Estrogen, secreted by the developing ovarian follicles, promotes the development of female secondary sexual characteristics such as breast development, widening of hips, and distribution of body fat. Testosterone is the male sex hormone. Progesterone prepares the uterus for pregnancy, and prolactin stimulates milk production.