Cell Cycle and Chromosomes

Affects germ cells and is inherited from one generation to the next generation

It has three 21 number chromosomes.

All deletion, duplication, inversion and translocation lead to structural change in chromosomes.

Due to addition or replication of one or more genes, the chromosomes become longer.

It is the change in the number or arrangement of nucleotides. It is the transfer of DNA from one bacterium to the other.

Q-banding is a fluorescent pattern obtained using quinacrine for staining. The pattern of bands is very similar to that seen in G-banding. They can be recognised by a yellow fluorescence of differing intensity. Most part of the stained DNA is heterochromatin. Quinacrin (atebrin) binds both regions rich in AT and in GC, but only the AT-quinacrin-complex fluoresces.

Interphase occurs just prior to cell division. Prepubertal male primordial germ cells are reactivated from interphase at puberty and enter rounds of mitoses followed by meiosis 1 and 2 to produce unique haploid sperm.

A human body has 23 pairs of chromosomes, out of which 22 pairs are autosomes and 1 pair is the sex determining pair.

Chromosomes that do not take part in the determination of sex are called autosomes. There are 22 pairs of autosomes in a human. This is the correct option. A human being has 22 pairs of autosomes and only 1 pair of allosomes.

Human females have two of the same kind of sex chromosomes (XX), while males have two distinct sex chromosomes (XY). The XY chromosomal cells create testosterone and anti-müllerian hormone to turn the genderless sex organs into male. With females, their cells excrete estrogen, driving the body down the female pathway. Thereby, determining the sex of the baby.

Karyokinesis refers specifically to the division of the cell nucleus during mitosis. The term comes from Greek: "karyon" meaning nucleus and "kinesis" meaning movement/division. Chromosomes are the structures that divide, but the process itself is called karyokinesis.

Ophioglossum reticulatum (2n = 1260): Highest known number of chromosomes in any life form. Myrmecia pilosula (2n = 2): 2 for females, males are haploid and thus have one; smallest number of chromosomes among all organisms.

During pachytene stage of meiosis I, each non-sister chromatid of homologous chromosomes exchange segments. This point of contact where crossingover takes place is termed as chiasmata.

Puffs in polytene chromosomes (such as those found in salivary gland chromosomes of Drosophila) are sites of active RNA synthesis, specifically transcriptional activity. These puffs represent regions where the chromatin has decondensed to allow gene expression. They are not sites of DNA duplication or protein synthesis - those processes occur elsewhere in the cell cycle.

A genome is defined as the complete set of haploid chromosomes found in each nucleus of a given species. It represents the complete genetic material of an organism. Option A correctly describes the genome as the haploid chromosome set. Option B refers to the total chromosome number (2n), not the genome.