Zusammenfassung der Ressource
Genes, Chromosomes and DNA
- Nucleus of cells contain genetic information
- Genetic material is arranged into chromosomes
- Humans have 23 pairs of
chromosomes
- Each chromosome is one long
molecule of DNA coiled up
- A gene is a short length of a chromosome
- Genes control the development of
different characteristics
- e.g: Hair Colour
- Genes exist in different versions
- Each version is a different form of characteristic
- Different versions are called alleles
- e.g: Eye colour
- Some characteristics are
controlled only by genes
- e.g: Dimples
- Sometimes by several working together
- Some characteristics are
controlled by environmental
factors
- e.g: Scars
- Each gene is a code for making a
specific protein
- Different versions of different
proteins means we end up with
different characteristics
- Functional proteins
- e.g: Enzymes
- Structural proteins
- e.g: Skin, hair, blood, cytoplasm
- An organism's genotype
depend on all the genes it has
- genes - genotype
- e.g: Bb
- Homozygous
- Two identical alleles
- bb
- heterozygous
- Two different alleles
- Bb