Cell Cycle and Chromosomes

Deletion is a type of chromosomal mutation in which a section of chromosome is lost, usually during mitosis or meiosis. Unlike some mutations, deletions are not usually reversible or correctable by a suppressor mutation.

The father's chromosomes determine the child's sex because males contribute either an X or Y chromosome while females always contribute an X. An XY combination produces a male, while XX produces a female.

Chromosomes are composed of DNA (nucleic acid) tightly coiled around histone proteins. This DNA-protein complex is called chromatin. The other options are enzymes (lypase), carbohydrates (glucose, sucrose) - not structural components of chromosomes.

Mitosis is the division process that occurs in somatic (body) cells to produce identical daughter cells for growth and repair. Ribosomes synthesize proteins, nucleic acids are molecules, and polymer is a general chemical term - not locations where mitosis occurs.

Cytokinesis is the division of the cytoplasm that completes cell division, occurring after nuclear division. Karyokinesis is nuclear division, plasmolysis is water loss in plant cells, and osmosis is water movement across membranes.

The four phases of mitosis are prophase (chromatin condenses), metaphase (chromosomes align), anaphase (sister chromatids separate), and telophase (nuclear membranes reform). Plastid, tonoplast, and leucoplast are not mitotic phases.

Karyokinesis specifically refers to the division of the nucleus during cell division, involving chromosome separation. Cytokinesis is cytoplasmic division, plasmolysis is water loss, and osmosis is water diffusion.

Meiosis occurs in reproductive cells (germ cells) to produce gametes (sperm and egg) with half the chromosome number. Enzymes catalyze reactions, exocytosis releases substances, and vacuoles store materials - none undergo meiosis.

Alleles are alternative forms of a gene that occupy the same locus (position) on homologous chromosomes and determine variations of the same character. For example, a gene for flower color may have alleles for purple or white. Genes are the broader functional units, while alleles are specific variants.

A locus is the specific fixed position on a chromosome where a particular gene is located. Each gene occupies its own locus, and different alleles of that gene occupy the same locus on homologous chromosomes. Centromeres are chromosome constriction points, while alleles are gene variants, not positions.

This is the correct option. In binary fission, cell elongation takes place, then invagination of cell wall and distribution of nuclear material, then formation of two cells takes place and then separation of two new cells happens.

Mitosis phase is the most important phase of the cell cycle.

Chromosomes are most condensed and visible at this stage.

Microspore mother cells are diploid (2N) and undergo meiosis to produce haploid pollens.

Plant cells lack centrioles, so during mitosis, spindle fibers originate from the cytoplasm or microtubule organizing centers in the cytoplasm. This is a key difference between plant and animal cell division.