Inheritance and Evolution

the fusion of two gametes’ nucleus

differences between organisms of the same species

a small section of a chromosome coded for certain characteristics

genetic code

23 from each parent

to make proteins

in a double helix

where an organism produces an identical clone

where 2 organisms produce an offspring which differin variety to the organisms

long coils of DNA

different versions of the same gene- dominant or recessive

where 2 alleles are the same

where 2 alleles are different

the genetic make up of an individual

the observable characteristics of an individual

We can use Punnett squares

changes in the genetic make up of an individual

categorical variation with no intermediates ( e.g. blood groups and shoe size)

variation that follows a range (e.g. weight and height)

a group of organisms that can interbreed and produce fertile offspring

the development of new species that occurs when two similar organisms are isolated, either due to the removal of habitiats, mountain formations or tectonic movement

where humans determine what desirable traits are passed down between organisms (e.g. cows that produce the most milk)

1. The animal dies in the sea and sinks to ocean floor
2. Skin is eaten away by smaller animals or breaks down
3. Sediment layers over the skeleton and packs the organism in stone- this takes millions of years
4. The bones break down and are washed away by ground water, leaving the imprint of the bones

prokaryotic cells- they don’t have a nucleus

Cell wall- for rigidity
Flagellum- for movement
Plasmids- allow bacteria to swap genetic info
Loop of DNA- genetic information

where bacterium resists medication that prevent cell wall synthesis- this is a problem as the more resistant genes are passed down and can cause harm

MRSA is a good example as it can mutuate and become stronger
1. MRSA enters the population
2. An antibiotic is administered and kills off the weaker bacteria
3. The resistant bacteria can then reproduce with no competition

when a species dies out

Habitat loss, overhunting, natural disasters, diseases, predators

disorders that are passed down from the parents to the offspring; caused by dominant or recessive alleles

having extra fingers or toes; caused by a heterozygous dominant allele

where the cell membranes are dysfunctional and affects the lungs with thick mucus; caused by homozygous recessive alleles