Pages in this set

Page 1

Preview of page 1
B2 revision May 22, 2012

DNA molecule

· First described by Watson & Crick
in 1953
· Double Stranded
· Twisted into a helix (spiral)
· Sugar Phosphate backbone
· Complimentary pairing of bases
Adenine = Thymine
Cytosine = Guanine
· Sections of DNA contain genes
responsible for producing proteins…

Page 2

Preview of page 2
B2 revision May 22, 2012


Page 3

Preview of page 3
B2 revision May 22, 2012


· Can be used to produce human insulin
· More effective than pig insulin
· Does not cause allergic reactions in


Page 4

Preview of page 4
B2 revision May 22, 2012

Advantages Disadvantages

· Wide range of products · optimum conditions required
e.g. human insulin, for most efficient growth
medicines, beer · low risk of contamination
· Can be used to grow · human views on eating
mycoproteins e.g. quorn microorganisms
· Quick and efficient

Page 5

Preview of page 5
B2 revision May 22, 2012

Exercise and respiration

Yeast can respire anaerobically
and are used to produce beer
and wine
glucose ethanol + carbon + energy
Anaerobic Respiration dioxide

The point at which your heart can no longer supply the muscles
fast enough.
glucose lactic acid + energy

· Does…

Page 6

Preview of page 6
B2 revision May 22, 2012

What is growth?

An increase in size or weight
Organisms of the same species can very in size
Some animals are able to regenerate e.g. star fish, gecko

Growth factors can be used to enhance performance

Look up examples of how these work and the…

Page 7

Preview of page 7
B2 revision May 22, 2012

Growth depends upon:
Differentiation Stem cells becoming other types of cell e.g skin,
bone, blood, nerve

Elongation Cells grow in size and length e.g. plant cells

Cell Division making many copies of cells to allow for tissue

Genes inherited from mother and father


Page 8

Preview of page 8
B2 revision May 22, 2012

Meiosis Production of gametes


Page 9

Preview of page 9
B2 revision May 22, 2012

mitosis meiosis

Provides cells for
growth and repair

Creates gametes

Daughter cells are
genetically identical

Four daughter

Daughter cells
are diploid


Page 10

Preview of page 10
B2 revision May 22, 2012

Summarise the views of people who are for or against
legal induced abortion.

Use evidence to decide whether the law should be
changed or not. Give reasons for your answer





Doesnt work

Similar Biology resources:

See all Biology resources »