Cell continuity + Mitosis.ppt

Cell Continuity

The principle that all cells develop from pre-existing cells through three steps:producing materials, growing larger, and reproducing.

Chromosomes

Structures in the nucleus made of DNA and protein; exist as chromatin when not dividing and as distinguishable chromosomes when dividing.

Haploid Cell (n)

A cell with one set of chromosomes, symbolized by 'n'; in humans, eggs and sperm are haploid with n=23.

Diploid

A cell with two sets of chromosomes, symbolized as '2n'; in humans, diploid cells have 46 chromosomes.

Homologous Pairs

Pairs of chromosomes in diploid cells, one from the mother and one from the father.

Cell Cycle

The life cycle of a cell, including interphase (non-dividing phase) and mitosis (dividing phase).

Interphase

The longest phase of the cell cycle, where the cell is active and prepares for division, accounting for 90% of a cell's life.

Mitosis

A form of nuclear division resulting in two identical daughter cells, each with the same number of chromosomes as the parent cell.

Cytokinesis

The process that follows mitosis, where the original cell divides to form two new cells.

Prophase

The first stage of mitosis where chromosomes become visible, the nucleolus disappears, and spindle fibers form.

Metaphase

The second stage of mitosis where chromatid pairs align at the cell's equator and spindle fibers attach to their centromeres.

Anaphase

The third stage of mitosis where sister chromatids separate and move to opposite poles of the cell.

Telophase

The final stage of mitosis where the nuclear envelope forms around each set of chromosomes, and chromosomes uncoil into chromatin.

Cleavage Furrow

The indentation that forms in animal cells during cytokinesis, leading to cell division.

Cell Plate

The structure that forms in plant cells during cytokinesis, leading to the formation of new cell walls.

Asexual Reproduction

A method of reproduction that does not involve the joining of two cells, as seen in unicellular organisms like amoeba.

Meiosis

A form of nuclear division that produces four haploid cells from a diploid cell, resulting in gametes (egg and sperm).

Gametes

Sex cells produced by meiosis, which have half the number of chromosomes (n=23) compared to the parent cell.

Oncogenes

Cancer-causing genes formed when normal genes are altered, often due to carcinogens.

Carcinogens

Agents that cause cancer, such as cigarette smoke, asbestos, ultraviolet radiation, and certain viruses.

Malignant Tumors

Tumors that invade other tissues and can spread throughout the body, a process known as metastasis.

What are the 3 stages of cell cycle

1. Interphase

2. Mitosis

3. Cytokinesis