Genetics

The female passes on DNA through her ovum, the female sex cell (gamete). This is where 1/2 of the child's chromosomes come from. (23 chromosomes)The male passes on DNA through his sperm, the male sex cell. This is where the other 1/2 of the child's chromosomes come from. (23 chromosomes)When the sperm and the ovum fertilise, there is one cell with 46 chromosomes.This cell continues to replicate through cell division, each cell with the same DNA.Males have XY chromosomes, whilst women have XX chromosomes.Normally, people have 23 pairs of chromosomes. Chromosomes are stored in the nucleus of each cellAlleles can be dominant or recessive.Homozygous - Same allele (rr, RR)Heterozygous - Different alleles (Rr)Punnet SquaresUsed to predict and determine genetic outcomes.Thins that can affect your physical appearance:Genetics (eye colour, height etc.)Environment (shade of skin,

Selective breeding - Choosing specific traits and characteristics to pass on to the next generation.e.g Speed, size, disease resistance, milk yield-Reduces genetic diversity-Increases chance of inherited diseasesGenetically Modified Organisms (GMOs) Commonly used in crops to make them larger/sweeter/cold resistant etc.Photosynthesis: CO2 +H2O -> C6H12O6 + O2Respiration: C6H12O6 + O2 -> CO2 + H2O Parts of a flower:Leaves - Large surface area -> more chloroplasts -> more sunlight collected -> faster photosynthesisAnther - Contains pollen (male gamete)Ovary - Contains ovum (female gamete)