Cells

Question 1

Cell surface membrane

Answer 1

Double layer of lipids and proteins

Surrounds cell separating cytoplasm from surrounding environment

Question 2

Mitochondria

Answer 2

Double bound membrane

Site of cellular respiration

Question 3

Chloroplast

Answer 3

Site of photosynthesis in plant cells

Question 4

Golgi apparatus

Answer 4

Responsible for transporting, modifying and packaging proteins and lipids

Question 5

Lysosomes

Answer 5

Breaks down molecules using enzymes

Question 6

Ribosome

Answer 6

Responsible for protein synthesis

Question 7

Rough ER

Answer 7

Protein production, protein folding

Studded with ribosomes

Question 8

Smooth ER

Answer 8

Production of cellular products like hormones and lipids

Question 9

Cell vacuole

Answer 9

Membrane bound structures

Filled with water, inorganic and organic molecules to support organelle

Question 10

Differences with prokaryotic and eukaryotic DNA

Answer 10

Prokaryotic -

circular dna

Question 11

How do B lymphocytes respond when they are stimulated by antigens

Answer 11

Activated by T cells
Divide by mitosis
To form memory cells and plasma cells
Plasma cells secrete antibodies

Question 12

What is an antigen

Answer 12

A large foreign molecule that stimulates an immune response

Question 13

How are number of chromosomes halved in meiosis

Answer 13

Homologous chromosomes

One of each goes to each pole

Question 14

Describe process of crossing over

Answer 14

Homologous pairs of chromosomes form a bivalent
Chiasma form
Alleles exchanged
New combinations of alleles produced

Question 15

How would chloroplasts be obtained from leaf tissue

Answer 15

Break tissues in cells
Centrifuge
At different speeds until chloroplasts obtained

Question 16

How to use cell centrifugation

Answer 16

Cell homogenisation 
Filter to remove debris
Use isotonic solution to prevent damage to cells
Keep cold to prevent damage to enzymes
Centrifuge to separate cell fragments 
Respin

Question 17

Principles of electron transmission microscope

Answer 17

Electrons pass through
Denser parts absorb more electrons
Denser parts appear darker
Electrons have short wavelength so give high resolution

Question 18

Why must cells be taken from root tip to view mitosis?

Answer 18

This is the region where mitosis takes place

Question 19

Why must you firmly squash the root tip to view mitosis?

Answer 19

To achieve one layer of cells so light can pass through, allowing it to be viewed on a microscope

Question 20

How do bacteria replicate?

Answer 20

Binary fission
Replication of DNA
Division of cytoplasm to produce 2 daughter cells
Each with a single copy of circular DNA

Question 21

What is a membrane formed from?

Answer 21

Phospholipids and proteins

Question 22

What are glycoproteins formed from?

Answer 22

Carbohydrates bound to proteins

Question 23

What is the fluid mosaic model?

Answer 23

The Fluid Mosaic Model states that membranes are composed of a Phospholipid Bilayer with various protein molecules floating around within it

Question 24

What links phospholipid molecules in the membrane?

Answer 24

Cholesterol

Question 25

Why do cells become more permeable at high temperatures?

Answer 25

The fatty acid tails of the phospholipid bilayer can become more fluid, allowing more movement

Question 26

Name 3 organelles that are membrane bound

Answer 26

Nucleus, vacuole, lysosomes

Question 27

What does a cell wall of a plant contain?

Answer 27

Meurin - a glycoprotein