Cell Structure

Question 1

What are two groups that all living organisms can be classified into?

Answer 1

Eukaryotes and prokaryotes

Question 2

Where is the DNA contained in a eukaryotic cell?

Answer 2

By a membrane bound nucleus

Question 3

Which cell in the body loses its nucleus over time

Answer 3

Red blood cell

Question 4

What is the protein called which the DNA is tightly wrapped around

Answer 4

Histones

Question 5

What does the DNA and histone protein both form together?

Answer 5

Chromosomes

Question 6

How is the tight coiling of DNA into chromosomes an advantage?

Answer 6

Means that a lot of DNA can be packed into the nucleus

Question 7

What does DNA being a linear molecule in eukaryotes mean?

Answer 7

The end of a DNA molecule in a chromosome are not joined together to form a loop

Question 8

Which organelles in a eukaryotic cell are membrane bound, in animal and plant cells?

Answer 8

Golgi apparatus, nucleus, mitochondria and endoplasmic reticulum, vacuole and chloroplasts

Question 9

What ribosomes are contained in eukaryotic cells?

Answer 9

80s ribosomes

Question 10

What is the cell wall in a plant cells made of

Answer 10

Cellulose

Question 11

What is the nuclear envelope and its function

Answer 11

A double membrane that surrounds the nucleus. controls what enters and exits the cells

Question 12

What is a nuclear pore

Answer 12

Allows the passage of large molecules such as mRNA out of the nucleus.

Question 13

What is nucleoplasm

Answer 13

Granular jelly like material that makes up majority of the nucleus

Question 14

What is a chromosome

Answer 14

Consist of a protein bound, linear DNA

Question 15

What is a nucleolus

Answer 15

A small spherical region within the nucleoplasm. It manufactures ribosomal RNA and assembles the ribosomes.

Question 16

Give three functions of the nucleus

Answer 16

• acts as the control centre of the cell through production of the mRNA and tRNA and hence protein synthesis
• retains genetic material of the cell in the form of DNA and chromosomes
• manufacture ribosomal RNA and ribosomes

Question 17

In a mitochondria what are cristae

Answer 17

Extensions of the inner membrane which provide a large surface area for the attachment of enzymes and other proteins involved in respiration

Question 18

What is the matrix in the mitochondria

Answer 18

Contains proteins lipids ribosomes and DNA and allows the mitochondria to control the production of their own enzymes

Question 19

What are mitochondria the site of

Answer 19

The site of aerobic respiration

Question 20

What is the function of chloroplasts

Answer 20

Organelles that carry out photosynthesis

Question 21

What is the grana in a chloroplast?

Answer 21

Stacks of disc like structures called thylakoids

Question 22

What is the function of grana?

Answer 22

Where the first stage of photosynthesis (light absorption) take place

Question 23

What is within the thylakoids

Answer 23

Chlorophyll

Question 24

What is the stroma in a chloroplast?

Answer 24

A fluid filled matrix where the second stage of photosynthesis (synthesis of sugars) takes place

Question 25

How are chloroplasts adapted for their function?

Answer 25

The granal membranes provide a large surface area for the attachment of chlorophyll, electron carriers and enzymes for light absorption for photosynthesis. The fluid of the stroma possesses all the enzymes needed to make sugars. The chloroplasts contain DNA and ribosomes so they can manufacture proteins needed for photosynthesis

Question 26

What is the endoplasmic reticulum?

Question 27

What are the 3 main roles of a lysosome

Answer 27

- transfer enzymes by exocytosis to digest dead cells/unwanted proteins - to digest bacteria in phagocytosis - to digest damaged/non-functional organelles