Biology unit 2

?

Investigating variation

Sampling

bias

Chance

Random sampling

Using a large sample size

Analyse

Environmental influence

1 of 10

Types of variation

Bar charts -  categoric data - genetic factors

Line graphs - normal distribution curve - continous data - environmental influence

Mean

Standard deviation

2 of 10

DNA

Structure of DNA

NUCLEOTIDE

Phosphate (backbone upright)

Deoxyribose sugar (backbone upright)

Organic base

Always goes with T

Greally goes with C

Complementary shape ( single + double ring)

3 of 10

Triplet Code

Minimum of three bases coded for each amino acid

64 possible codes

20 amino acids

Introns - multiple repeats

Degenerate - more than one code

4 of 10

Chromosomes

Eukaryotic - linear dna molecules that occur in association with proteins

Visible during cell division

Homologus

Occurs in pairs

Maternal and paternal

Pair always determines the same characteristics

ALLELE - DIFFERENT VERSION OF A GENE

5 of 10

Genetic diversity

Diversity

Selective Breeding + ethics

Founder effect

Bottleneck effect

6 of 10

Variety of Life

Haemoglobin

4 polypeptide chains  - each associated with a haem group containing a ferrous ion

Readily associates with oxygen in the lungs

Readily dissociates with oxygen in the tissues

Affinity - high - take up easy, let go not so easily

Affinity - low - take up less easily , more readily releases

7 of 10

Dissociation Curves

Oxygen partial pressure

Effects of CO2 concentration

Tissues - high - reduces oxygen affinity

Lungs - low

8 of 10

Polysaccharides

PLANTS

STARCH

CELLULOSE

ANIMALS

GLYCOGEN

9 of 10

Plant cell structure

LEAF PALISADE

CHLOROPLASTS

CELL WALL

SPECIALISED

10 of 10

Comments

No comments have yet been made

Similar Biology resources:

See all Biology resources »See all Health, illness and disease resources »