Objective Questions with Answers on Biology

Answer: Option [C]

Arrangement of chromosomes in the order of decreasing length is termed as Idiogram. Idiogram is a composite photograph or diagram of metaphasic chromosomes of haploid or diploid set of an organism arranged in a series of decreasing size, thickness position of centron-iere and shape.

Answer: Option [C]

The correct answer is sex linked. Sex-linked traits are determined by genes located on the sex chromosomes. Sex-limited traits are determined by genes located on autosomes and express only in one sex. While these traits are responsible considerably for sexual dimorphism, sex-influenced traits do not show distinctive expression between women and men.

Answer: Option [A]

Tjio and Levan's contribution is very significant because they gave the number of human chromosomes. In 1956, Tjio and Levan were the first to accurately describe that humans have 46 chromosomes. This discovery was technically the first very low-resolution whole-genome analysis and opened the field of clinical cytogenetics.

Answer: Option [D]

Polytene or giant chromosomes are found in Salvary glands of Drosophila. Polytene chromosomes are found in dipteran flies: the best understood are those of Drosophila, Chironomus and Rhynchosciara. They are present in another group of arthropods of the class Collembola, a protozoan group Ciliophora, mammalian trophoblasts and antipodal, and suspensor cells in plants.

Answer: Option [B]

The correct answer is The centromere in the former is terminal and the later is subterminal.