Topic 2 (Cells, mitosis and meiosis)

Question 1

Describe the cell theory?

Answer 1

The Cell Theory include:
1. All known living things are made up of cells.
2.The cell is the structural & functional unit of all living things.
3. All cells come from pre-existing cells by cellular division.
4. Cells contain hereditary information which is passed from cell to cell during cell division.
5. Any living cell must have 3 general properties:
▪Metabolism
▪Growth
▪Reproduction

Question 2

Compare and contrast prokaryotic and eukaryotic cells?

Answer 2

Similar in? Whereas…
i.e. Size, presence of plasma membrane, cell wall, cytoplasm, nucleus, specialized organelles, ribosomes

Question 3

Describe the structure and functions of nucleus and ribosomes?

Answer 3

Nucleus
- Command center of the cell
2 main functions-
- store genetic material (DNA) of the cell for cell division
- Assemble ribosome subunits for protein synthesis

Ribosome
- Each made up of one large subunit and one small subunit
- site of protein synthesis

Question 4

List the functions of ER, Golgi, lysosomes, mitochondria?

Answer 4

Rough ER:
-site of protein synthesis

Smooth ER:
-Participates in detoxification
- Site of lipid synthesis

Golgi:
-modifies protein structure
-Packages protein in secretory vesicles

Lysosomes:
- breaks down unwanted macromolecules

Mitochondria:
-Major site of ATP synthesis

Question 5

Describe the structure and functions of cell membrane?

Answer 5

Structure:
A phospholipid bilayer with many associated proteins

Function:
Forms a continuous barrier around living cells, separates cell’s cytoplasm components from external environment.

Question 6

Describe cell cycle in eukaryotes?

Answer 6

G1:
-protein synthesis
-increase in size
-generate ATP

S:
- DNA replication

G2 (similar to in G1):
- more protein synthesis
- further increase in size
- generate ATP

M (mitosis):
- nuclear division

Cytokinesis
- cytoplasmic division

Question 7

List the stages of mitosis?

Answer 7

PMAT
-Prophase
-Metaphase
-Anaphase
-Telophase

Question 8

Describe the events that occur during mitosis?

Answer 8

Explain Interphase, PMAT and Cytokinesis

Watch: https://www.youtube.com/watch?v=lsG0t9KzTO8

Question 9

Describe the events that occur during meiosis?

Answer 9

Explain PMAT

Question 10

Compare mitosis and meiosis?

Answer 10

In notes

Question 11

Describe how the properties of phospholipids help to maintain the structure of the cell membrane?

Answer 11

Hydrophilic heads arrange themselves towards aqueous environment, hydrophobic heads repel water and arrange themselves away from water, forming the inner core of the bilayer.