Inheritance, Variation and Evolution

• Chromosomes are made up of DNA which contains genes that determine characteristics such as eye colour or height
• DNA is the genetic material found inside chromosomes.
• Genes are sections of DNA that code for specific traits.
• Alleles are different versions of a gene.
• Dominant alleles mask recessive ones so they don't show up in an organism's phenotype.
• Recessive alleles only appear when two copies of them are present (homozygous).
• Homozygous means having two identical alleles for a particular trait.
• Gametes (eggs/sperm) contain half the number of chromosomes compared to body cells.
• During fertilization, one gamete from each parent fuses together to form a zygote with a full set of chromosomes.
• Genetic variation is important because it allows individuals to adapt to changing environments by producing more diverse traits.
• Crossing over results in new combinations of genes that were not previously found in either parent or offspring.
• Variation refers to differences between individuals within a population due to genetic or environmental factors.