Inheritance and Variation (DNA Deoxyribonucleic acid (Double helix shape,…
Inheritance and Variation
are made up of lengths of DNA wrapped around a protein.
involves two parents where the male and female gametes join together to form a zygote.
a sperm joins with an egg to form a baby.
involves one parent with the offspring having identical genetic information to the parent.
a strawberry produces runners to make more identical strawberries.
Double helix shape
Sides of helix made up of sugar and phosphates
‘Steps’ of DNA made up of bases
There are four bases: adenine, thymine, guanine and cytosine
The way members of the same species differ is known as
Variation is caused by changes in the DNA (
Variations in humans: dark hair/light hair, blue/brown eyes
Variations in dogs: coat colour, coat length
Humans have 46 chromosomes in each cell.
23 from Mother and 23 from Father
are lengths of DNA along a chromosome.
Pairs of genes control a particular trait.
The gene for a trait is located on two chromosomes
: when the protein a gene is controlling is actually made
: genes an organism possesses
: the trait that can be seen in the organism
: a gene that prevents another gene from working
: a gene that is prevented from being expressed
Dominant gene=capital letter Recessive Gene = small letter