B1: You and your genes

Most cells in your body have a nucleus- and it's the nucleus that contains your genetic material
The genetic material in the nucleus is arranged into Chromosomes. The human cell nucleuscontains 23 pairs of Chromosomes.
Each Chromosome is one very long molecule of DNA that's coiled up(the coiling gives chromosomes their shape.
A gene is a short length of a chromosome.
Genes control the development of different characteristics, e.g, hair colour, and how an organism functions
Genes can exist in different versions. Each version gives a different form of a characteristic like blue or brown eyes. The different versions of the same gene are called alleles.
Genes are instructions for cells
1. Each gene is a code for making a cetain protein
2. Having different versions of proteins means that we end up with different characteristics
3. Some proteins are structural proteins. they ate patr of things like hair, skin and blood and the cytoplasm in out cells.
4. Other proteins are functional proteins- for example. enzymes are proteins that help with digestion by breaking down food molecules.
Organisms genotype describes the genes its got
1. Organisms genotype are all the genes it has. The Characteristics that an organism displays are called its phenotype.
2. Some characteristics such as dimples are controlled by genes alone.
3. Other characteristics- scars. are controlled by environmental factors
4. There are also other characteristics that are controlled by both genes and environmental factors

Resource summary

	Created by plusterianne almost 11 years ago