Barr body is also known as sex chromatin or X chromatin. Barr body is partially inactivated and development of this facultative heterochromatin occurs in one of the two X chromosomes in interphase nuclei of human female. Any of the two X-chromosomes can become heterochromatin.

Transfer of phosphate group from ATP to a carbohydrate is referred to as phosphorylation and is carried out in the presence of phosphorylase enzymes. E.g., glucose (a carbohydrate) is phosphorylated to glucose-6-phosphate by ATP in the presence of enzyme hexokinase or glucokinase and Mg²⁺.

Retrogressive metamorphosis occurs in Urochordates (e.g., Herdmania, Ascidia, Doliolum etc.), in which better developed (advanced) larva changes to less developed (primitive) adult.

Like other alkali metals, potassium hydroxide combines with CO₂ as such: ­
2KOH+CO₂ $\to$K₂CO₂ +H₂O

Gibberellins induce the production of hydrolysing enzymes in the endosperm of germinating seeds. It stimulates the production of digestive enzymes like proteases, amylase and lipase which help to mobilise stored nutrients.

A checkpoint is one of several points in the eukaryoticcell cycle at which the progression of a cell to the next stage in the cycle can be halted until conditions are favorable.

DDT (Dichloro diphenyl trichloroethane) is a colourless, crystalline, tasteless and almost odourless organochloride known for its insecticidal properties. DDT is not derived from any plant rather it is prepared by the chemical reactions of some chemical compounds.

Opioids (opiates) are the analgesic drugs that are derived from latex of unripe fruits of poppy plant, Papaver somniferum. Similarly, cocaine and cannabinoids are the drugs derived from Erythroxylon coca (Coca plant) and Cannabis sativa (Hemp plant) respectively

Erythropoietin is a glycoprotein produced by the kidney, which regulates red blood cell formation in the bone marrow. During kidney damage, enough erythropoietin required for adequate RBCs production is not synthesised resulting in anaemia

Excretory organs of grasshopper are the Malpighian tubules and the main excretory product  is uric acid. Malpighian tubules of insects such as grasshoppers not only help to excrete the waste but also function to conserve water, which is then used in other metabolic activities. In the Malpighian tubules, bicarbonates of potassium and sodium, water and uric acid are formed during the process, of excretion. A large amount of water and bicarbonates of potassium and sodium are reabsorbed by the cells of Malpighian tubules and then transferred to the blood (haemolymph). Uric acid is carried to the alimentary canal of the insect and is finally passed out through anus.

The given floral diagram is of Family Fabaceae. Flower - zygomorphic, bisexual. Sepals -five, fused. Petals - five, polypetalous, papillionaceous corolla. Androecium - ten, diadelphous. Gynoecium - ovary superior, monocarpellary, unilocular, marginal placentation, with many ovules.