inheritance

• how many chromosomes do human cells have?

  23 pairs
• what are the stages of mitosis?


  DNA replicates and cell enlarges

  chromosomes are pulled to each end of the cell and then nucleus divides into 2

  cell membrane and cytoplasm divide to form 2 identical daughter cells
• what are functions of mitosis


  • essential for growth and development of multicellular organisms

  • mitosis takes place when an organism repairs itself

  • happens during asexual reproduction
• how many chromosomes in gametes?

  23
• where does meiosis take place?

  reproductive organs (testes/ovaries)
• what is the structure of DNA?


  double helix
• explain protein synthesis?


  transcription:

  • base sequence of a gene is copied into a template (mRNA)

  • mRNA passes out of nucleus into cytoplasm

  translation:

  • mRNA attaches to a ribosome

  • amino acids are brought to ribosome on carrier molecules (tRNA)

  • ribosome reads triplet of bases and uses it to join correct amino acids in correct order

  • once protein is complete, it folds to its unique shape