The Cell

Question 1

What does a human cell consist of?

Answer 1

• cytoplasm and nuceloplasm
• organelles
• nucleus
• cell membrane

Question 2

What cell doesnt have a nucleus?

Answer 2

Red blood cells

Question 3

Describe the structure of the cell membrane?

Answer 3

• 2 layers of phospholipids with protein and carbohydrate molecules embedded in them
• arranged with heads to outside and tails to inside
• selective barrier, regulates passage of substances

Question 4

What is the protoplasm?

Answer 4

Transparent jelly like material which is the living substance of the cell

Question 5

What are the 2 types of protoplasm?

Answer 5

• cytoplasm- inside the cell, outside nucleus
• nucleoplasm- protoplasm within the nucelus

Question 6

What is the function of protoplasm?

Answer 6

• reproduction
• responds to stimuli
• chemical processes take place

Question 7

Describe mitochondria?

Answer 7

Mitochondria are membraneous, sausage shaped organelles

Question 8

What is the function of mictonchondria

Answer 8

Contains enzymes that synthesise ATP

Question 9

What cells have the greatest number of mitochondria?

Answer 9

The most metabolically active cells have greatest number of mitochondria eg liver and muscle

Question 10

Describe the composition of ribosomes

Answer 10

Tiny granules composed of ribosomal RNA & protein

Question 11

What is the function of ribosomes

Answer 11

They synthesise proteins from amino acids, using mRNA as a template

Question 12

Where are ribosomes found?

Answer 12

• The outer surface of nuclear envelope
• rough endoplasmic reticulum

Question 13

What is endoplasmic reticulum?

Answer 13

An extensive series of interconnecting membraneous canals in the cytoplasm

Question 14

What is the function of smooth endoplasmic reticulum?

Answer 14

• synthesises lipids and steroid hormones
• detoxifies some drugs and converts glycogen to glucose

Question 15

What is the function of rough endoplasmic reticulum?

Answer 15

Its studded with ribosomes, site of protein synthesis

Question 16

Describe the Golgi apparatus?

Answer 16

Consists of stacks of closely folded flattened membraneous sacks

Question 17

Where is golgi apparatus found?

Answer 17

In all cells but larger in those that synthesise & export proteins

Question 18

What is golgi apparatus the site of?

Answer 18

Exocytosis

Question 19

What is a lysosome?

Answer 19

Small membraneous vesicles pinched off from golgi apparatus

Question 20

Describe the structure of a cytoskeleton

Answer 20

Consists of extensive network of tiny protein fibres

Question 21

What is the function of a cytoskeleton?

Answer 21

Provides an internal support system for organelles within the cell

Question 22

What are the 4 stages of mitosis

Answer 22

• prophase
• metaphase
• anaphase
• telophase