reproduction

• What is sexual reproduction?

  when the gametes(haploid)-egg and sperm fuse together to produce a zygote with 46 chromosomes(diploid).
• What is asexual reproduction?

  When the parent cell divides . This produces genetically identical offspring called clones.
• What does sexual reproduction include?

  -two parents

  -offspring genetically different

  -fertilisation

  -sex cells present
• What does asexual reproduction include?

  -one parent only

  -all offspring genetically identical

  -no fertilisation

  -no sex cells
• Advantages of sexual reproduction

  -there is genetic variation

  -disease cannot spread easily and kill populations
• Disadvantages of sexual reproduction

  -takes time and energy

  -need to find a mate

  -produces fewer offspring
• Advantages of asexual reproduction

  -only one parent needed

  -fast reproduction

  -all offspring are clones
• Disadvantage of asexual reproduction

  -no genetic variation

  -disease can spread easily and kill populations
• Why is it important for gametes to be haploid?

  to restore the diploid number of chromosomes at fertilisation
• Function of jelly coat layer

  -cell membrane hardens

  -chemicals are released
• Function of ciliated epithelial cell

  -found in fallopian tube

  -they move side to side to move the egg from the fallopian tube to uterus
• Function of acrosome

  -releases digestive enzymes

  -breaks down cell membrane of egg cell
• Function of flagellum

  -allows sperm cell to swim
• Function of mitochondria

  -releases energy to help flagellum move
• Describe how sperm cells are adapted for their function

  -Acrosome- releases digestive enzymes and breaks down cell membrane of egg cell

  -Flagellum- allows sperm cell to swim

  -Mitochondria- releases energy to help flagellum move

  -Nucleus- carries 23 chromosomes(haploid) to restore 46 chromosomes(diploid)
• Describe how egg cells are adapted for their function

  -Jelly coat layer- releases chemicals to harden egg cell membrane

  -Cytoplasm- contains nutrients for the growth of embryo

  -Mitochondria- where respiration takes place