1.2 Eukaryotic cells

Question 1

What is the endosymbiotic theory?

Answer 1

Chlorophyll and mitochondria may have been prokaryotic cells that were eaten by a bigger prokaryotic. It attempts to explain the origin of eukaryotic cells. This is because chlorophyll and mitochondria both have double membranes, their own DNA, and divide separate from the cell (replicate via binary fission). Also, they are of similar size to prokaryotic cells.

Question 2

What is the function of the nucleus?

Answer 2

• contains DNA
• where RNA is synthesized
• control center of the cell

Question 3

What is the function of mitochondria?

Answer 3

• metabolic functions
• generates most of the cell’s energy
• able to kick start apoptosis

Question 4

What is the function of lysosomes?

Answer 4

• break down substances with hydrolytic enzymes
• may function with endosomes - transport and package material coming in or out of cell
• can kick start apoptosis

Question 5

What is the function of endoplasmic reticulum? (ER)

Answer 5

• rough ER - has ribosomes that synthesis proteins that are sent directly to the lumen
• smooth ER - used for lipid synthesis and detoxification of some drugs and poisons
• SER transports proteins from RER to golgi

Question 6

What is the function of the golgi apparatus?

Answer 6

• receives materials from ER that are delivered in vesicles

- modifies, packages, and sends out cellular materials

Question 7

What is the function of peroxisomes?

Answer 7

• contains hydrogen peroxide
• breaks down long chain fatty acids via beta-oxidation
• synthesizes phospholipids
• contains enzymes involved in pentose phosphate pathway

Question 8

Do all cells have the same composition and number of organelles?

Answer 8

No, cells differ in the composition and number of their organelles depending on their function.
Ex. sperm have a lot of mitochondria as they require lots of energy for movement.
Ex. blood cells have no organelles as they only have transport functions that don’t require any.

Question 9

The cytoskeleton is made up of what 3 parts?

Answer 9

1. Microfilaments
2. Microtubules
3. Intermediate filaments

Question 10

What is the basic structure of flagella and cilia of eukaryotes?

Answer 10

Eukaryotic flagella and cilia have 9 pairs of microtubules forming an outer ring and 2 microtubules in the center. It is known as the 9+2 structure.

Question 11

What are the four tissue types?

Answer 11

1. Nervous
2. Muscle
3. Epithelial
4. Connective