reproduction

• sexual reproduction

  • is a type of reproduction where gametes are produced by meiosis
  • a gamete from each parent fuses to make a zygote, genes from each gamete is mixed resulting in unique zygotes
• gametes

  sex cells - sperm and egg cell

  • haploid = cell with 26 chromosomes, half the normal amount
• meiosis

  cell division to form gametes. Chromosome number is halved and the cell is divided twice, rather than once like in mitosis

  • interphase occurs before meiosis
• why is meiosis important for sexual reproduction ?

  • increases genetic variation
  • ensures the zygote is diploid, has 46 chromosomes
• advantage of sexual reproduction ?

  • created genetic variation which increases the probability of species adapting to surviving environmental changes
• disadvantage of sexual reproduction ?

  • two parents required, makes reproduction for endangered reproduction or species which exhibit solitary lifestyles difficult
  • a lot more time and energy is required, so fewer offspring are produced
• asexual reproduction :

  • type of reproduction which involves mitosis
  • produces genetically identical offspring known as daughter as cells, plants usually reproduce like this
• advantage of asexual reproduction :

  • only one parent required
  • lots of offspring can be produced in short period of time, enabling colonisation of areas and less competition with other species
  • requires less energy
• disadvantage of asexual reproduction :

  • no genetic variation
  • reduces probability of specie being able to adapt to environmental changes