Biology

• Reproduction


  The process by which an organism produces others of the same kind. The purpose is to make sure an organism's species can continue to survive.
• Types of reproduction


  • Asexual
  • Sexual
• Asexual reproduction


  • New organism or organisms are produced from one organism
  • The offspring will be genetically identical to the parent organism, much like a clone
• Asexual reproduction methods


  • Budding
  • Regeneration
  • Binary Fission
  • Parthenogenesis
  • Vegetative
• Budding


  New organisms arise as an outgrowth from the parent organism
• Regeneration


  Regrow severed body parts | Some animals can grow new organisms from severed pieces
• Binary Fission


  Parent organism divides to become two separate daughter organisms | Types of cell division found in prokaryotic organisms like bacteria
• Parthenogenesis


  Female produces without mate | Offspring produces from unfertilised eggs | Insects and bees
• Vegetative


  Fragment of the parent plant (cutting or grafting)
• Sexual reproduction


  • The egg and sperm are required for the fertilisation of the egg
  • The egg and sperm join to create a zygote which will produce offspring similar to but different from the parent organisms
• Sexual reproductive structures in humans and flowers

  • Petals
  • Sepals
  • Stem and Receptable
  • Stamen
  • Carpel

  
• Petals


  Protection of reproductive structures, attract pollinators
• Sepals


  Protect developing flower bud
• Stem and Receptable


  Connect the flower to the rest of the plant
• Stamen


  • The male part
  • Anther - produces pollen
  • Filament - supportive stalk
• Carpel


  • The female part
  • Stigma - sticky landing pad
  • Style - delivery tube
  • Ovary - produces ovum
• Fertilisation


  Fusion of gametes to create a zygote (first cell of a new individual)
• Advantages of asexual reproduction

  • Only one parent is needed
  • Conserves energy
  • Every individual can produce offspring
  • Faster reproduction
  • If the parent is suited to its environment so are all the offspring
• Disadvantages of asexual reproduction

  • No genetic variations in offspring
  • If a parent is not well-adapted, all offspring are identical
  • Less chance of surviving changes in the environment
• Advantages of sexual reproduction

  • Genetic Variation in Offspring
  • More chance of surviving changes
  • Reduces risk of extinction
• Disadvantages of sexual reproduction

  • Need two parents
  • Costs energy; making reproductive systems
  • Courtship behaviour
• Delivery system for gametes


  • Need a delivery system to ensure gametes meet inside the organism
  • Nurture young till 'Birth' as an infant or fruit/seed - Requires uterus/ovary
• Human reproduction


  • Involves internal fertilisation and internal development of the foetus
  • Typically humans have few offspring, and can therefore invest a large amount of of energy into the care, nurturing and development of their offspring
• Fertilisation


  The union of a sperm and an egg
• Gametes


  • Female gametes are called eggs or ovum
  • Male gametes are sperm or pollen
• Gametes


  DNA from other body cells as they contain only have ( 1 set of chromosomes) of the DNA, also known as sex cells. They form by the cell division type called - meiosis.
• Zygote


  The First cells because they contain both gametes of the DNA
• Cell types


  • Haploid - 1 copy of each chromosome, half set of genetic material, Gametes
  • Diploid - 2 copies of each chromosome, full set of genetic material, Zygote, most body cells

  
• Female reproductive system parts

  • Ovaries
  • Fallopian Tubes
  • Uterus
  • Cervix
  • Vagina
• Ovaries


  Produces eggs and manufactures female hormones, oestrogen and progesterone
• Fallopian Tubes


  Used to capture ova to the uterus. They are usually the site of fertilisation
• Uterus


  Houses and nourishes the human baby of the foetus during the pregnancy
• Cervix


  Creates a barrier from pathogen entry into the uterus. Allow for sperm to reach the egg
• Vagina


  Where sperm are deposited. It is also the Birth canal
• Male reproductive system parts

  • Testes
  • Epididymis
  • Vas Deferens
  • Seminal vesicle & prostate gland
  • Urethra
  • Penis
  • Scrotum
• Testes


  Produces sperm and male hormone testosterone
• Epididymis


  Stores the sperm while it matures
• Vas Deferens


  Transports sperm from the epididymis to the seminal vesicles
• Seminal vesicle & prostate gland

  Secrete fluids containing glucose and pH neutraliser that form part of the semen
• Urethra


  Carries semen and urine outside of the body