Cell biology

• What is mitosis


  Cell division that generates new cells for growth and repair. The division of one cell into two genetically identical daughter cells
• What types of cells do mitosis

  Skin cells
• What is the 1st stage of the cell cycle?

  Cell growth leads to DNA SYNTHESIS

  DNA which makes up chromosomes makes an exact copy of itself.
• What is the next stage?

  Mitosis
• what are the stages of mitosis?

  to 1. Chromosomes line up in the middle of the cell

  2. One set of chromosomes get pulled each way to different poles

  3. 2 new nuclei form

  4. cytoplams and cell membrane form around the two new nuclei

  5. Cytokenisis - cell splits into 2 daughter cells
• What is a stem cell?

  an undifferentiated cell
• Where can stem cells be found?

  - embryos

  - adult bone marrow

  - plant meristems
• What are adult stem cells for?

  Replacing dead or damaged cells.

  They are unable to differente as embryonic cells can.
• What may stem cells help with for medical purposes?

  - Help paralysed patients by transferring new nerve cells into a damaged CNS (spine/brain)

  - Treat diabetes - replace the cells that are no longer working

  - replace faulty organs

  - replace choroid eye cells to help vision
• What is theraputic cloning?

  Producing an embryo with the same DNA as a patient, so that stem cells can be used for medical treatment. The stem cells will not rejected by the patient's body.
• What is a totipotent stem cell?

  a cell that can differentiate into any cell type ie embryo cells
• What are some ethical issues which may arise with embryonic stem cells?


  - Killing potential life

  - May amount for murder
• What are dangers of using stem cells ?

  - May use an infected stem cell - leads to viral infections

  - May be rejected by the donor's body
• What is mitosis


  Cell division that generates new cells for growth and repair. The division of one cell into two genetically identical daughter cells
• What types of cells do mitosis

  Skin cells
• What is the 1st stage of the cell cycle?

  Cell growth leads to DNA SYNTHESIS

  DNA which makes up chromosomes makes an exact copy of itself.
• What is the next stage?

  Mitosis
• what are the stages of mitosis?

  to 1. Chromosomes line up in the middle of the cell

  2. One set of chromosomes get pulled each way to different poles

  3. 2 new nuclei form

  4. cytoplams and cell membrane form around the two new nuclei

  5. Cytokenisis - cell splits into 2 daughter cells
• What is a stem cell?

  an undifferentiated cell
• Where can stem cells be found?

  - embryos

  - adult bone marrow

  - plant meristems
• What are adult stem cells for?

  Replacing dead or damaged cells.

  They are unable to differente as embryonic cells can.
• What may stem cells help with for medical purposes?

  - Help paralysed patients by transferring new nerve cells into a damaged CNS (spine/brain)

  - Treat diabetes - replace the cells that are no longer working

  - replace faulty organs

  - replace choroid eye cells to help vision
• What is theraputic cloning?

  Producing an embryo with the same DNA as a patient, so that stem cells can be used for medical treatment. The stem cells will not rejected by the patient's body.
• What is a totipotent stem cell?

  a cell that can differentiate into any cell type ie embryo cells
• What are some ethical issues which may arise with embryonic stem cells?

  - Killing potential life

  - May amount for murder
• What are dangers of using stem cells ?

  - May use an infected stem cell - leads to viral infections

  - May be rejected by the donor's body
• what are eukaryotes


  plant and animal cells - complex organisms/multicellular
• What are prokaryotes?


  bacteria - single celled

  - don't contain nucleic dna
• What are structural features of eukaryotes?

  Cell membrane

  cytoplasm

  genetic material in nucleus

  divides by mitosis
• What are structural features of prokaryotes?

  Much smaller

  Plasmid DNA - singular loop

  Cell wall + membrane

  Cytoplasm

  ribosome

  Divide by binary fission
• What structural features do animal cells have?

  Cell membrane

  Cytoplasm

  Ribosomes

  Mitochondria

  Nucleus
• What structural features does a plant cell have?

  Cellulose cell wall

  Cell membrane

  Cytoplasm

  Permanent vacuole

  nucleus

  Ribosome s

  chloroplasts

  Mitochondria
• What is a specialised cell?

  A cell which has adapted to complete a specific function
• How is a sperm cell specialized to fertalise an egg?

  Tail - help them swim faster

  Mitochondria - release energy during respiration so they can keep swimming
• How is a nerve cell specialised to send and receive signals?

  Very long - axens and myelin sheaths insulates the electrical impulse

  Cell body has smaller extensions - can pick up impulses from nearby cells
• How is a muscle cell specialised to contract and relax?

  
  

  
  

  Muscle cell mitochondria - releases lots of needed energy
• How is a root hair cell specialised to allow absorbtion from the roots?

  Small thin extension which pokes into soil - increases surface area meaning plant can absorb more
• What is a xylem cell?

  specialised to transport water up the stem of a plant and into the leaves
• How is xylem cells adapted for it's function?

  Dead xylem cells , sealed with lignin - no end walls - hollow tube, strong due to the lignin, act as a transport tube
• What is the purpose of the phloem cells ?

  Carry glucose from the leaves to all other parts - used for respiration