Skeleton and Movement — Biology STD 11 Science — Question

Several genera resembling one another in their major anatomical and reproductive characters are placed together in :

Which type of teeth are maximum in number in human buccal cavity?

The tissue that stores fats in mammals is

___________ is commonly known as hookworm.

Kupffer cells are found in

Cockroach is a/an animal.

Gymnosperms are characterized by the absence of

In a particular flower the insertion of floral whorls was in such a manner, so the ovary was below other three whorls, but its stigma was taller than other three whorls. What will you call such flower?

Crossing over takes place between which chromatids and in which stage of the cell cycle?

Invertebrates, bony fishes, tadpoles, etc. are ammonotelic. Whereas birds, reptiles, land snails, etc. are uricotelic. What would be the probable reason for the difference in mode of excretion?
i. Ammonotelic organisms conserve water as conversion of ammonia to uric acid requires large amount of water.
ii. Elimination of ammonia requires large quantity of water, thus ammonotelism is seen in aquatic animals.
iii. Uricotelic organisms require moderate water for eliminating urea and formation of ammonia requires expenditure of energy. Thus, to conserve water and energy, these animals have uricotelism mode of excretion.
iv. Aquatic animals can retain ammonia and store it in the body for long time.