Basic Biology: Cell Cycle and Cell Division

Flashcards about Basic Biology, Cell Cycle and Cell Division. Structure of chromosome. Mitosis and its stages. A basic understanding of Meiosis as a reduction division. Basic structure of chromosome with elementary understanding of terms such as chromatin, chromatid gene structure of DNA and centromere.

Cell division

The method used by life to perpetuate generation after generation, involving chromosome distribution into daughter cells.

Mitosis

Ensures normal cell functioning through the life of an organism by maintaining the same type and number of chromosomes in all body cells.

Chromatin

The complex of DNA and proteins that make up chromosomes.

Chromosomes

Highly coiled structures formed by the condensation of chromatin fibres during cell division.

Walther Flemming

A German scientist who first studied chromosomes in animal cells in 1881.

Histone proteins

The proteins that help in the coiling and packaging of DNA into structural units called nucleosomes.

Nucleosomes

Structural units formed by DNA strands winding around a core of eight histone proteins.

Nucleotide

The repeating units composed of a pentose sugar, phosphate group, and nitrogenous base that form the basic structure of nucleic acids (DNA/RNA).

Purines

Adenine (A), Guanine (G).

Pyrimidines

Thymine (T), Cytosine (C), Uracil (U).

Scientists who discovered the shape of DNA

Rosalind Franklin, Watson and Crick.

Centromere

The point of attachment of the two sister chromatids of a chromosome.

Genes

Segments of nucleotide sequences on a DNA strand that determine particular inherited characteristics.

DNA fingerprinting

A technique used for identifying individuals by examining their unique DNA patterns.

Mitosis

The process by which cells divide for growth, replacement and repair, maintaining the same number of chromosomes.

Centromere

The two sister chromatids of a chromosome are attached to each other at this location.

Cell cycle

A series of events that take place in a cell leading to the duplication of its DNA and the division of the cell to produce two daughter cells.

Interphase

A non-dividing phase of the cell cycle where cells prepare for the next division and grow to the same size as their mother cell.

Sub-phases of interphase

G1, S and G2.

S-phase

The phase of interphase in which DNA molecules (chromosomes) duplicate for equitable distribution into daughter cells during mitosis.

Mitosis

Cell division leading to the production of diploid cells for growth and development.

Meiosis

Cell division leading to the production of haploid cells or gametes (sperms or egg).

Mitosis

The cell division in which one parent cell divides into two identical daughter cells, maintaining the same chromosome number.

Two steps of Mitosis

Karyokinesis and Cytokinesis.

Four phases of Karyokinesis

Prophase, Metaphase, Anaphase, and Telophase.

Prophase

The chromosomes become short and thick and are clearly visible inside the nucleus, centrosome splits into two, nuclear membrane disappear.

Metaphase

The duplicated chromosomes arrange on the equatorial plane and get attached to a spindle fibre by its centromere.

Anaphase

Centromere attaching the two chromatids divides, and the two sister chromatids of each chromosome separate and move towards the opposite poles.

Telophase

Each daughter chromosome lengthens and becomes a network of chromatin threads, the nuclear membrane reappears.

Karyokinesis

Division of nucleus.

Cytokinesis

Division of cytoplasm.

Meiosis

Cell division leading to the production of gametes.

Crossing over

Mixing up of genes (genetic recombination).