Cell divison notes

What is cell division?

The process by which a cell divides into two new cells.

Why do living things need to divide their cells?

1. To grow by producing more cells, not just by increasing cell size. 2. To repair damaged tissue. 3. To manage nutrient and waste exchange as the cell increases in size.

What is mitosis?

A form of asexual reproduction where two genetically identical cells are produced from one parent cell.

How do bacteria reproduce?

Bacteria reproduce asexually by a process called binary fission.

What occurs during Step 1 of binary fission?

The cell wall prepares for replication.

What happens in Step 2 of binary fission?

The cell makes a copy of its single, circular chromosome.

What occurs during Step 3 of binary fission?

The cell grows larger, and chromosomes separate to opposite poles.

What is cytokinesis? (step 4)

The division of the cytoplasm that occurs after mitosis, resulting in two identical cells.

What structure in eukaryotic cells contains DNA?

The nucleus.

What is chromatin?

DNA in non-dividing cells that appears as long thread-like structures.

What happens to chromatin during cell division?

Chromatin condenses into chromosomes.

What are sister chromatids?

Identical copies of a chromosome joined at the centromere.

What is the function of a centromere?

It holds the two sister chromatids together.

In which type of cells does mitosis occur?

Somatic cells, such as muscle, bone, and skin cells.

What is interphase?

The life cycle phase where a cell prepares for division, consisting of G1, S, and G2 phases.

What happens during the G1 phase of interphase?

The cell grows in size and makes more proteins and ribosomes.

What happens in the S phases (DNA Synthesis)

The cell replicates its chromosome (DNA) and Sister Chromatids are formed .

What occurs during the G2 phase of interphase?

Organelle replication occurs, and chromosomes will coil and condense becoming more visible. Centrioles will rep as a replicate sult we will have pairs in the cell.

What are centrioles?

Organizing Spindle Fibers

What are spindle fibers?

Microtubules that pull chromosomes apart during mitosis.

What are the main stages of mitosis?

1. Prophase 2. Metaphase 3. Anaphase 4. Telophase.

What happens during prophase?

Chromosomes coil up and condense, the nuclear envelope disappears, and spindle fibers form.

What occurs during metaphase?

Chromosomes line up in the middle of the cell, and spindle fibers attach to them.

What is anaphase?

Sister chromatids are pulled apart to opposite poles by spindle fibers.

What occurs during telophase?

Chromosomes uncoil, nuclear envelopes reform, and spindle fibers disappear.

What is the result of mitosis?

Two identical nuclei are formed, followed by cytokinesis which divides the cell.

What is the difference between benign and malignant tumors?

Benign tumors are non-cancerous and do not spread, while malignant tumors are cancerous and do spread to other tissues.

What is metastasis?

The process of cancer cells spreading to other parts of the body.

What are the roles of the centrioles during cell division?

To organize spindle fibers during mitosis.

What is the significance of the nucleolus during cell division?

The nucleolus disappears during prophase and reappears during telophase.

What is mutated DNA?

DNA that has undergone a change in its nucleotide sequence, potentially leading to altered protein function or regulation.

What are centromeres?

The specialized region of the chromosome that holds the two sister chromatids together.

What is a cleavage furrow?

In Animal cells the cell membrane pinches in creating a cleavage furrow which will deepened with the action of contracting proteins at the same time of the cell membrane until cell is divided into cells.