Reproduction + genetics

• In the female reproductive system:

  • Eggs are produced in the ovaries
  • They travel along the oviduct by the help of hair-like cilia towards the uterus
  • Sperm are deposited in the vagina
  • Fertilised egg travels along the oviduct and imbeds in the wall of the uterus to develop
  • The lining of the uterus is known as the 'Endometrium'
• Mutation is a random change to genetic material, such as the loss of a section of DNA with three base pairs
• Mutations in genes can alter the structure of the protein made, potentially changing an individual's phenotype
• Mutations can be advantageous (increasing survival and reproduction chances), disadvantageous (decreasing survival), or neutral (no effect)
• A mutation is a change to the DNA within a gene, which can lead to serious diseases like Cystic fibrosis and Sickle cell anaemia
• Inheritance involves receiving one form of a gene from the mother and one form from the father
• Variation in species is due to differences in genes, influenced by genetic variation, environmental causes, or a combination of genes and the environment
• Examples of characteristics influenced by the environment include scars, muscle development, and hair length
• A gene is a short length of DNA carrying instructions for a characteristic, and you inherit two copies of each gene, one from each parent
• DNA profiling is a forensic technique used to identify individuals, create DNA fingerprints, and can be used in crime-solving or determining relationships
• DNA, deoxyribonucleic acid, contains genetic information and has a double helix structure made of two strands connected by bases (A, T, C, G)
• Sex cells are haploid with 23 chromosomes; when they fuse during fertilization, they form a diploid zygote with 46 chromosomes
• Sexual reproduction in humans involves the production of sex cells (sperm and egg) in specialized sex organs (testes and ovaries)
• In the male reproductive system, sperm cells are produced in the testes, travel along the sperm duct, and leave the body through the urethra as semen
• The oviduct is where fertilisation occurs
• The ovary is where egg cells are produced
• The uterus is where implantation occurs and where the foetus develops
• The cervix is a ring of muscle between the vagina and the uterus
• The vagina is where the penis is placed during intercourse
• The penis deposits sperm into the vagina during sexual intercourse.
• The sperm duct carries sperm from the testes to the urethra
• The gland adds to fluid to the sperm to make semen
• The urethra carries sperm/urine out of the body.
• The testis is where sperm is produced and stored.
• The scrotum is the sac that holds the testes outside of the body and is covered by skin.
• Fertalisation occurs when the nucleus of the sperm fuses with the nucleus of the egg cell to form a zygote.
• BB - Homozygous dominant

  Bb - Heterozygous

  bb - Homozygous recessive
• Homozygous means the 2 alleles are the same
• Heterozygous mean the 2 alleles are different
• A genotype if the combination of alleles for a characteristic
• The phenotype is the physical characteristic outcome of the genotype
• Genetic engineering is when a gene from from one organism is taken and inserted into the DNA of another organism