Animal Cell Ultrastructure

Question 1

What does plasma membrane do

Answer 1

• controls exchange of substance between cell and external environments
• has receptors for cell recognition

Question 2

What does the nucleus have

Answer 2

1. Nuclear envelope (double membrane)
2. Nuclear pores which allows mRNA to leave
3. Chromatin - singular unwound chromosomes

Question 3

Purpose of cytoplasm

Answer 3

1. Where chemical reactions take place
2. Organelles are suspended in cytoplasm

Question 4

Purpose of RER

Answer 4

Covered with ribosomes
Helps transport proteins made in ribosomes to where they are needed

Question 5

Purpose of mitochondrion

Answer 5

Site of aerobic respiration
Rod shaped that have the purpose of energy release by making ATP
Consists of smooth outer layer and folded inner layer

Question 6

Purpose of Golgi body

Answer 6

Secretion from cell.
Close to nucleus (stack of membrane bound sacs)
Receives protein from RER modifies and processes it and packages it into vesicle to be released

Question 7

Purpose of SER

Answer 7

no ribosomes unlike RER
important in synthesising and transporting lipids and steroid hormones

Question 8

Purpose of lysosome

Answer 8

Membrane bound containing digestive enzymes as such as hydrolyric enzymes

Involved in destruction of cells, bacteria, ageing cells to release digestive enzymes to degrade other cells.

Question 9

Purpose of centrioles

Answer 9

Pair of them next to nucleus
Involved in cell division generate spindle fibres that are responsible for the separation of chromosomes

Question 10

Role of cytoskeleton

Answer 10

Provide strength and support
Determines shape of cell
Involved in movement of organelles
Hold organelles in place
Make centrioles and spindle fibres

Micro tubules- help move organelles
Microfilaments - act as Skelton and support and responsible for cell movement

Question 11

Flagella and cilia role/structure

Answer 11

Hair like extensions
Involved in movement
Cilia short and flagella are long
Cylinders with 9 micro tubules arranged in circle and 2 micro tubules in centre

Have arms/ motor protein that push one ahead of each other by ATP that make it bend

Question 12

Chloroplasts

Answer 12

Site of photosynthesis

Question 13

Cell wall

Answer 13

Supports cell
Prevents bursting
Allows exchange of substances

Question 14

Vacuole

Answer 14

Helps maintain pressure within cell prevents wilting and keeps it rigid
Contains cell sap