Reproduction

• What are the two main types of reproduction?

  Sexual and asexual reproduction
• What are the advantages of sexual reproduction?

  • Produces variation in offspring
  • Increases survival advantage in changing environments
  • Decreases extinction risk for the species
  • Allows for selective breeding
• How does variation in offspring benefit a species?

  It increases survival chances in changing environments
• What is a survival advantage?

  A characteristic that helps an organism survive
• What is a key advantage of asexual reproduction?

  Only one parent is needed
• What is a benefit of asexual reproduction in favorable conditions?

  It produces many identical offspring quickly
• What is fertilization in plants?

  Fusion of male and female gametes
• What are the adaptations of insect-pollinated plants?

  • Large, bright petals to attract insects
  • Scented nectar to lure pollinators
  • Sticky pollen grains in moderate amounts
  • Stiff anthers for easy pollen transfer
  • Sticky stigma for pollen attachment
• What are the adaptations of wind-pollinated plants?

  • Small, dull petals (often green or brown)
  • No scent or nectar
  • Smooth, light pollen grains in large amounts
  • Loose anthers for easy pollen release
  • Feathery stigma to catch drifting pollen
• What are the male and female gametes in plants?

  Pollen grains and ovules
• What are the steps of seed and fruit formation in plants?

  1. Pollen lands on stigma
  2. Pollen tube grows to ovule
  3. Male nucleus fuses with female egg nucleus
  4. Zygote undergoes mitosis to form seed
  5. Ovule becomes seed; ovule wall becomes seed coat
  6. Ovary becomes fruit
• What is germination?

  The process seeds develop into a plant
• What conditions are needed for seed germination?

  • Water: activates enzymes for starch breakdown
  • Oxygen: needed for aerobic respiration
  • Warmth: optimum temperature for enzyme activity
• What is the method for testing seed germination conditions?

  1. Set up 4 boiling tubes with cress seeds
  2. Tube A: dry cotton wool at 20°C
  3. Tube B: moist cotton wool at 20°C
  4. Tube C: boiled water with oil at 20°C
  5. Tube D: moist cotton wool at 4°C
• Which test tube will show germination and why?

  Tube B, due to water, temperature, and oxygen
• What are the structures of germinating seeds and their functions?

  • Embryo: develops into the adult plant
  • Food store: starch for energy until photosynthesis
  • Seed coat: protective covering
• What does the prostate gland produce?

  Semen containing sperm cells
• Where are sperm produced in males?

  In the testis
• What is the function of the penis?

  Passes urine and semen out of the body
• What is the role of the ovary in the female reproductive system?

  Contains ova that develop with FSH
• What is the function of the uterus?

  Implants fertilized eggs
• What are secondary sexual characteristics in females?

  • Breast development
  • Menstrual cycle begins
  • Growth of body hair
  • Widening of hips
  • Increased height
• What are secondary sexual characteristics in males?

  • Growth of penis and testes
  • Production of sperm
  • Growth of facial and body hair
  • Muscle development
  • Voice lowering and breaking
• How long does the menstrual cycle last?

  28 days

  
• When is the egg usually released during the menstrual cycle?

  On day 14 (ovulation)
• What does oestrogen do during the menstrual cycle?

  Thickens the uterus for egg implantation
• What happens to oestrogen levels on day 10 of the menstrual cycle?

  They peak and then begin to fall
• What is the role of progesterone in the menstrual cycle?

  Maintains the thick lining of the uterus
• When does progesterone start increasing during the menstrual cycle?

  After the egg matures on day 14
• example of natural asexual reproduction

  runners
• example of artificial asexual reproduction

  cuttings
• seed contains

  radicle (root)

  plumule (shoot)

  one/two cotleydons
• function of the cotyledons

  food store used for initial growth until the plant can photosynthesise
• where does fertilisation occur

  oviduct
• function of the testis

  produces sperm and testosterone
• function of the uterus

  where fertilised eggs are implanted

  where the embryo develops
• function of FSH

  matures egg
• function of LH

  releases egg during ovulation
• FSH stimulates

  oestrogen
• oestrogen inhibits

  FSH