Reproduction Flashcards
Describe the structure of an insect pollinated flower
- Large and brightly colored petals to attract insects
- They have scent and nectar(花蜜) which attracts insects
- Large and sticky pollen grains which can be attached to insects
- Anther is inside the flower
- Stigma is inside the flower
Describe the structure of a wind pollinated flower
- Small and dull petals
- No scent or nectar（花蜜）
- Large amount of pollen grains as most pollen grains are not transferred to another flower.
- Smooth and small pollen grain so they can be blown away by the wind
- Anther is outside of flower, swinging loose which makes it easier for wind to carry them away
- Stigma is outside flower so it will be easier to catch pollen grains that flying around
Conditions for germinating seeds
presence of water, oxygen and have a suitable temperature
Describe an investigation to investigate the conditions needed for seed germination
- Set up four tubes.
- Tube A with no water
- Tube B with no suitable temperature(4 degrees) (moist cotton wool
- Tube C with no oxygen (boiled water with layer of oil on top)
- Tube D with perfect condition (control)
Results:
- Tube A: No growth (Enzymes are not activated)
- Tube B: No growth( enzymes does not function at that low temperature)
- tube C: No growth (No oxygen for respiration so no energy for germination)
method of asexual reproduction in plants
Runners: Horizontal stems such as strawberry
What is the sperm duct used for
Sperm passes through the sperm duct to be mixed with fluids produced by the glands before being passed into the urethra for ejaculation
What does the urethra do
A tube which carry out urine or semen. A ring of muscle in the urethra prevents the urine and semen from mixing
What does the testis do
Contained in a bag of skin and produces sperm and testyosterone
What does the scrotum do
A sac which keeps sperm at temperatures slightly lower than the body temperature
What does the oviduct do
connects the ovary to the uterus and is lined with ciliated cells to push the released ovum down it. Fertilization occurs here
What does the ovary do
Contains the egg which will mature and develop when hormones are released
what does the uterus do
Fertilized egg(zygote) will be implanted to develop into a foetus
What does the cervix do
Keep the developing fortuitous in place during pregnancy
does meiosis produce gametes or mitosis
Meiosis
Three differences between mitosis and meiosis
-mitosis produces two daughter cells whereas meiosis produces four
- Mitosis produces diploid cells whereas meiosis produces haploid cells
-Daughter cells produced by mitosis are genetically identical whereas daughter cells produced by meiosis are genetically diverse.
