mitosis and meiosis

List the structures of the prokaryotic and eukaryotic genomes.

Prokaryotic: genome includes a large chromosome and smaller plasmids

Eukaryotic: genome includes pairs of chromosomes found in the cell’s nucleus and a circular chromosome in both the mitochondria and chloroplasts

Explain what is meant by homologous chromosomes.

• Matching pairs

• Contain the same genes at the same position

Distinguish genes and alleles.

Alleles are different versions of the same gene

Genes are a segment of a DNA that codes for a specific trait

Explain how diploid and haploid cells are different from one another and give examples of each.

Diploid cells have 2 of each chromosome, one from each parent

• Somatic Cells

Haploid Cells have 1 of each chromosome

• Gametes

Differentiate between chromosomes, sister chromatids, and chromatin. 

Chromatin are the relaxed and uncoiled version of genetic material.

Chromosomes are a highly condensed structure made of chromatin that becomes visible during cell division.

Sister chromatids are two identical halves of a single, replicated chromosome. They are joined at the centromere and are pulled apart during cell division. 

List the parts of the cell cycle in order.

Interphase: G1, S, G2

Mitotic phase: Prophase, Prometaphase, Metaphase, Anaphase, Telophase, and Cytokinesis

Describe what occurs during each stage of the cell cycle. 

Interphase

• G1: cell growth, checks to see if there are enough nutrients available for a new cell to grow and checks for growth factors

• S: DNA synthesis, centrosome duplication

• G2: More growth, preparation for mitosis, organelle duplication, both centrosomes are visible

Mitosis

• Prophase

• Prometaphase

• Metaphase

• Telophase

Describe what occurs during each phase of mitosis.

Prophase- chromosomes condense and become visible, spindle fibers emerge from the centrosomes, nuclear envelope breaks down, and the nucleolus disappears.

Prometaphase- chromosomes continue to condense, kinetochores appear at the centromeres, mitotic spindle microtubules attach to kinetochores, and centrosomes move toward opposite poles

Metaphase- mitotic spindle is fully developed centrosomes are at opposite poles of the cell, chromosomes are lined up at the metaphase plate, and each sister chromatid is attached to a spindle fiber originating from opposite poles

Anaphase- cohesin proteins binding the sister chromatids together break down, sister chromatids (now called chromosomes) are pulled towards opposite poles, non kinetochore spindle fibers lengthen, elongating the cell

Telophase- chromosomes arrive at opposite poles and begin to decondense, nuclear envelope material surrounds each set of chromosomes, and the mitotic spindle breaks down

Cytokinesis- 

• In animal cells, a cleavage furrow separates the daughter cells

• In plant cells, a cell plate separates the daughter cells

Identify each phase of mitosis in images.

yeah idk

Explain what occurs during cytokinesis. 

The process of dividing the cytoplasm of the cell and results in two identical cells

• In animal cells, the plasma membrane of the parent cell pinches together in the middle, forms a deep cleavage furrow, which separates the two new cells

• In plant cells, a cell plate forms between the two new cells, and the plate becomes the plant cell wall

Explain why it is important to regulate the cell cycle.

It is important to regulate the cell cycle to prevent genetic errors, ensure cells divide correctly, and maintain the health of an organism.

Explain how factors internal and external factors (e.g, cell density, and anchorage dependence) can impact cell division.

Cell density, no division

Missing growth factors, no division

Too few chromosomes, no division

Anchorage dependence ensures that each type of cell in the body survives and divides when only it is in an appropriate condition. It means that cells will not divide if they are not attached to a growth surface

Density dependence means that cells will not divide if they are “squeeze together” with too many other cells

Explain how the growth of cancer cells is different from the growth of normal cells.

Cancer cells divide without external growth signals and divide even with mutations or issues with chromosome duplication or spindle attachment

Describe the importance of checkpoints in general and specifically the M checkpoint.

Checkpoints regulate the process of mitosis. The M checkpoint checks for chromosome spindle attachment to ensure that genetic information is not too much or too little in each cell.