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B1 (Cell structure, Cell division, Mitosis, Transport in cells) - Coggle…

- - - - animal
        
        0.01-0.05mm
      - plant
        
        0.01-0.1mm
      - the human eye can see 0.05mm
    - - uses 2 lenses to magnify something
        
        the eyepiece
        
        an objective lens
        
        usually a choice of objective lenses to use
        
        magnification of a microscope = magnification of eyepiece x magnification of objective lens
    - - measuring a cell in a microscope is done using an eyepiece graticule
        
        it has a scale ruled on it
        
        to calibrate the graticule you use a stage micrometer
  - - - to stain cells to examine with a light microscope
      - examine a range of cells
    - - add drop of water to slide, swab cheek, rub cotton bud in water droplet
      - add drop of water to slide, peel 1 layer of onion, gently place onion in water droplet
      - put a drop of stain on the slide next to the specimen, draw stain under specimen with filter paper
  - - - examine, make observations, draw results
    - - rotate objective lenses so that lowest power is in line with stage
      - turn coarse focus so it is closest to stage
      - place slide
      - focus slide with coarse focus
      - draw a lower power image
      - refocus with fine adjustment
    - - low power
        
        plan to show tissues or outlines of cells
      - high power
        
        detailed image of cell
  - - - then developed by hooke
    - - resolution 200nm
      - uses light
    - - uses beams of electrons
      - transmission electron microscope has higher resolution
  - - - cytoplasm
        
        jelly, where many chemical reactions happen
      - nucleus
        
        genetic material, cells activities
      - cell membrane
        
        controls ins and outs
      - mitochondria
        
        respiration
      - ribosomes
        
        proteinsynthesis
  - - - chloroplasts
        
        contains chlorophyll for photosynthesis
      - cell wall
        
        strengthens and supports cell
      - permanent vacuole
        
        filled with cell sap
  - - - head contains genetic material for fertilisation
        
        acrosome in head lets it penetrate the egg
      - whole thing packed with mitochondria for energy to swim
      - tail for swimming
    - - extended cells so that they can run around the body
      - it has extensions and branches so it can communicate with other nerve cells
      - covered with fat for insulation
        
        speeds nerve impulse
    - - contains proteins that slide to contract
      - many mitochondria
    - - large surface area
        
        more contact with soil water
      - thin walls not to restrict movement of water
    - - no top or bottom to make a continuous tube
      - thickened walls for support
    - - bidirectional
      - sieve plates provide required energy
- - - - each chromosome is one molecule of dna
        
        it condenses and replicates itself when it is ready to divide
    - - it is a code for what protein to make
    - - 23rd pair are sex chromosomes
        
        female is XX
        
        male is XY
  - - - length of time in phase = observed number of cells in that stage/total number of cells observed x total length of time for cell cycle
  - - - dna replicates
      - chromosomes line up
      - one set of chromosomes pulled to each side
      - nucleus divides
      - cytoplasm and cell membrane divide to form 2 identical daughter cells
  - - - brain
      - eyes
      - blood
      - heart
      - liver
      - bone marrow
      - skin
      - muscle
      - they can differentiate into related cells
    - - by therapeutic cloning
        
        transplants can be done by a donor or their own
        
        therapeutic cloning can produce cells with the same genetic make up as patient
        
        this is done with the nucleus of the patients cell
        
        transferred to an egg cell with no nucleus
        
        the new cell is stimulated to divide and form an embryo
        
        then cultured
        
        benefits and issues for the use of stem cells in medicine
        
        benefits
        
        great potential in treating currently untratable conditions
        
        clinical issues
        
        no guarantee
        
        limited donors
        
        chance of mutations
        
        cells can be contaminated
        
        ethical issues
        
        obtaining embryonic stem cells uning IVF
        
        creating embryos for therapy then destroying them along the way
        
        should the embryos be treated as people
        
        social issues
        
        educating public is difficult
        
        weighing out positives and negatives
        
        chance of patients being exploited
    - - found in meristems
      - can be used to make clones of plants quickly and cheaply
  - - - these must divide and differentiate to make an organism
    - - circulatory system
        
        transport substances, regulate temp, defend body
      - excretory system
        
        remove waste products, regulate water
      - muscular system
        
        movement
      - nervous system
        
        respond to stimuli, carry messages
      - respiratory system
        
        deliver oxygen
      - reproductive system
        
        fertilisation
      - skeletal
        
        movement and protection
    - - leaf
        
        palisade mesophyll
        
        photosynthesis
        
        spongy mesophyll
        
        allow gases to circulate
        
        guard cells
        
        control gas exchange
      - xylem
        
        transport water and dissolved substances up plant
      - phloem
        
        sieve tubes
        
        transport products from photosynthesis to where needed
        
        companion cells
        
        provide energy required
      - growing plants - meristem
        
        produce new cells as they divide
  - - - cells from meristems can be cloned
        
        they can be grown in agar with nutrients
        
        its quicker than natural growth
      - they are genetically identical
      - they can be done large scale
- - - - isolated plant cells can take in water via osmosis
        
        the strong cellulose wall is fully permeable allowing water through
        
        this also stops it bursting