The disease caused by the deficiency of vitamin B₁ is: MCQ with Answer and Explanation

Explanation:
Tissue culture is a technique where plant cells, tissues, or organs are grown on a synthetic nutrient medium (like MS medium) under aseptic conditions to regenerate whole plants. It exploits totipotency. It is used for micropropagation, production of disease-free plants, and conservation. Cloning produces genetically identical individuals, genetic engineering alters DNA, hybridization crosses different varieties.

Explanation:
Rana tigrina is the scientific name of the Indian bullfrog. Homo sapiens refers to humans, Felis domestica is the domestic cat, and Crocodylus palustris is the marsh crocodile. Binomial nomenclature gives each organism a unique genus and species name. Rana is the genus, tigrina the species, both italicized when printed.

Explanation:
Mammalia is the only class of animals that possess mammary glands, which produce milk to nourish their young ones. Other defining features of mammals include the presence of hair on the skin, external pinnae (ear flaps), a four-chambered heart, and being warm-blooded (homeothermic). Examples include humans, whales, and bats.