Reproduction and inheritance
- Reproduction in plants
- Sexual vs asexual
- Two parents or one
- Gametes fuse or not
- Variation or clones
- Fertilisation
- Gametes fuse
- Zygote
- Embryo
- Flowers and pollination
- Insect-pollinated
- Wind-pollinated
- Anther to stigma
- Seed and fruit formation
- Pollen tube
- Ovule to seed
- Ovary to fruit
- Germination
- Water
- Oxygen
- Warmth
- Food reserves
- Asexual reproduction
- Runners
- Cuttings
- Clones
- Sexual vs asexual
- Human reproduction
- Male system
- Testes
- Sperm duct
- Prostate gland
- Penis
- Female system
- Ovary
- Oviduct
- Uterus
- Cervix and vagina
- Menstrual cycle
- Oestrogen repairs lining
- Progesterone maintains lining
- Ovulation day 14
- FSH and LH Biology only
- FSH matures egg
- LH causes ovulation
- Placenta
- Diffusion of nutrients
- Villi
- Umbilical cord
- Amniotic fluid
- Absorbs shocks
- Puberty
- Oestrogen
- Testosterone
- Secondary sexual characteristics
- Male system
- DNA and protein synthesis
- Genome: all the DNA
- entire DNA of organism
- Gene
- section of DNA
- codes for a protein
- Chromosomes in nucleus
- genes located on them
- DNA structure Biology only
- double helix
- A–T and C–G
- two strands
- RNA Biology only
- single stranded
- uracil replaces thymine
- Transcription Biology only
- in nucleus
- makes mRNA
- Translation Biology only
- at ribosome
- tRNA anticodons
- mRNA codons
- polypeptide made
- Genome: all the DNA
- Inheritance
- Alleles
- alternative forms of gene
- Terms
- dominant, recessive
- homozygous, heterozygous
- genotype, phenotype
- Codominance Biology only
- both alleles expressed
- roan cattle
- Polygenic inheritance
- many genes
- e.g. height
- Monohybrid crosses
- Punnett square
- 3 : 1 ratio
- Pedigrees and probability
- carriers
- 1 in 4 chance
- Sex determination
- XX female, XY male
- sperm decides
- 50% each
- Alleles
- Cell division, variation and evolution
- Mitosis
- two identical cells
- diploid, 46
- Uses of mitosis
- growth
- repair
- cloning
- asexual reproduction
- Meiosis
- four different cells
- haploid, 23
- makes gametes
- Random fertilisation
- genetic variation
- Variation
- genetic
- environmental
- or both
- Mutation
- rare, random change
- can be inherited
- source of variation
- Mutation and phenotype Biology only
- changes amino acid sequence
- most: no effect
- Mutagens Biology only
- ionising radiation
- tobacco chemicals
- Natural selection
- variation
- survive and reproduce
- alleles passed on
- Antibiotic resistance
- mutation
- selection pressure
- hard to control
- Mitosis