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Question 1

Structures in common to ALL cells.

Answer 1

1. Genetic material (DNA)
2. Plasma membrane
3. Ribosomes
4. Cytoplasm - the fluid matrix filling the cell and surrounding the internal structures. It permits reactions to occur in an aqueous environment.

Question 2

Distinguish the four phases of the eukaryotic cell cycle.

Answer 2

G1 (Growth phase 1) of Interphase

• cell grows in size, as organelles duplicate

S (synthesis)

• replication of DNA
• centrosome (centriole) replicated

G2 (second growth)

• DNA is proof-read
• enzymes for division are made

Mitosis: Nuclear Division Role (PMAT)

• A parent nucleus divides into two nuclei
• The DNA is redistributed into two new cells and is identical in both cells.

Telophase /Cytokinesis - Animal

• spindle fibers breakdown
• nuclear envelopes reform around both groups of chromosomes
• chromosomes form tight mass.
• nucleoli reappear
• cytokinesis occurs by a cleavage furrow, enclosing each daughter nucleus into a separate cell

Telophase/Cytokinesis - Plant

• Chromosomes are at the poles of the cell.
• Nuclear membrane is reforming
• Chromosomes begin to relax (unfold)
• Cytokinesis begins. Note the cell plate between the two chromosome bundles

Question 3

Draw and label a schematic diagram of the cell cycle. Describe the events occuring in each phase in words.

Answer 3

https://cdn.kastatic.org/ka-perseus-images/6afac0fce62ec8a30c86f3e02c457224339bb697.png

Question 4

Draw cells in each stage of mitosis

Answer 4

https://www.yourgenome.org/wp-content/uploads/2022/04/mitosis_yourgenome.png

Question 5

Compare and contrast mitosis in plant and animal cells.

Answer 5

Distinction betweenPlant Cell vs Animal Cell

Plant cells form cell plate in cytokinesis
- vesicles line up and fuse; cellulose is placed between the two new cells.
- Aster forms from centrosome (an MTOC that develops only when a cell divides

Animal cells: form of a cleavage furrow in cytokinesis.
- A ring of microtubules contract, pinching the cell in two.
- Aster forms from centrioles

Question 6

Compare similarities and differences between mitosis and meiosis

Answer 6

Mitosis
1. Produces identical diploid cells
2. Occurs in somatic cells
3. Produces somatic cells
4. For growth and repair
5. One cell division
6. Same number of chromosomes in daughter cells compared with parent cell

Meiosis
1. Produces genetically different haploid cells
2. Occurs in germ line cells
3. Produces gametes
4. For reproduction
5. Two cell divisions
6. Half number of chromosomes in daughter cells compared with parent cell

Question 7

Correctly identify sister chromatids, tetrads and chromosomes

Answer 7

Tetrad: A group of four closely associated chromatids of a homologous pair formed by synapsis.

A chromatid is one of the two identical halves of a chromosome that has been replicated in preparation for cell division. The two “sister” chromatids are joined at a constricted region of the chromosome called the centromere.

Question 8

Recognize the need for meiosis in reproduction.

Answer 8

Meiosis is important because it ensures that all organisms produced via sexual reproduction contain the correct number of chromosomes. Meiosis also produces genetic variation by way of the process of recombination.