STD 12 - 8. microbes in human welfare — Biology STD 12 Science — Question

$(i)$ Queen Elizabeth shows a number of haemophilic descendents.

$(ii)$ Variation in blood group prevalences due to incomplete dominance.

$(iii)$ Drosophila has three pairs of autosomal chromosomes.

$(iv)$ In birds, female is heterozygous.

1. Lymphocytes become more active.
2. Body attacks self cells.
3. More antibodies are produced in the body.
4. The ability to differentiate pathogens or foreign molecules from self cells is lost.

$(a)$ It results in the formation of haploid gametes

$(b)$ Differentiation of gamete occurs after the completion of meiosis

$(c)$ Meiosis occurs continuously in a mitotically dividing stem cell population

$(d)$ It is controlled by the Luteinising hormone (LH) and FollicleStimulating Hormone (FSH) secreted by the anterior pituitary

$(e)$ It is initiated at puberty

Choose the most appropriate answer from the options given below: