Laboratory 9 Mitosis

Mitosis

Asexual division of somatic/body cells. Produces two identical daughter cells from a single parent cell. Function to facilitate the growth of an organism and replaces damaged or worn-out cells. Requires precision

Meiosis

Sexual form of cell division. Produces genetically different daughter cells from a single parent cell and is usually confined to tissues with an exclusively reproductive function, such as the gonads. Because meiosis is associated only with sexual reproduction, its function is to create genetic variability among offspring.

Gametes

Product of meiosis

Interphase

No cell division is occuring. Majorty of the time in the cell cycle. Contains G1, S, G2

G 1

Primary growth, just doing its thing. First

S

Replciates DNA, Second

G 2

Third. Secondary growth, replicates everything else other than DNA for the two new daughter cells

What are the two copies of DNA called

Sister chromatids

Cytokinesis

Divides the cytoplasm

Prophase

The nucleus disappears and the chromosomes begin to condense and attach to the mitotic spindle apparatus

Metaphase

Chromosomes are fully condensed and the chromosomes are aligned along the equator of the spindle apparatus. The equator is conceptualized as a metaphase plate, but that is not an actual cell structure

Anaphase

The chromosomes split and individual sister chromatids move towards opposite poles of the cell

Telophase

Sister chromatids reach one of the poles. The chromosomes start to decondense. The spindle apparatus breaks down and the nuclear membrane reforms.

Cytokinesis in plants

Build dividers, division=cell plate

Cytokinesis in animals

Form a clevage furrow

How does the number of chromosomes differ between the plant and animal cell

Each species (whether plant or animal) has its own unique and characteristic number of chromosomes. A key difference is that plants are more likely to be polyploid, meaning they can have multiple copies of their entire set of chromosomes, while most animals are diploid and have only two copies (one from each parent). 

Where would a region of active cell division in humans be?

Regions of active cell division in humans include the skin's basal layer, the lining of the digestive tract, and bone marrow, which are all areas with high cell turnover.

Do all types of human somatic cells divide at the same rate?

No, not all human somatic cells divide at the same rate; some, like neurons, divide very rarely or not at all, while others, such as those in the gut, divide constantly.