• Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month
Page
  1. 1
    1
  2. 2
    2
  3. 3
    3
  4. 4
    4
  5. 5
    5
  6. 6
    6
  7. 7
    7
  8. 8
    8
  9. 9
    9
  10. 10
    10
  11. 11
    11
  12. 12
    12
  13. 13
    13
  14. 14
    14

mitosis coursework

Extracts from this document...

Introduction

Biology Assessed practical Coursework 1 Mitosis in garlic root cells Mitosis is the division of one cell to form 2 daughter cells, mainly found useful for repairing tissue, replacing cells and is also used in asexual reproduction. Mitosis can also be named, nuclear division. Nuclear division is divided into four stages, Prophase, metaphase, anaphase, telophase. The first stage, Prophase, is where nuclear division begins. In early prophase, the centriole replicates itself and the chromosomes begin to coil up; they become shorter, thicker, stain more intensely and become much more visible. During late prophase, the centrioles move to opposite poles of the nucleus and the nuclear envelope 'disappears' (it breaks up into small vesicles not visible by a light microscope). The nucleolus disappears to form parts of chromosomes. The second part of nuclear division is metaphase. In this stage the chromosomes line up along the equator of the spindle (in the centre of the 2 centrioles at opposite poles). Spindle fibres reach out from the centrioles and attack themselves to the chromosomes. The spindle fibres then split the chromosomes, and the cromasomes break at the centromere, both halves of each chromosome are pulled apart. The next phase, anaphase, is where the chromotids (two identical sister chromatids make up one chromosome) ...read more.

Middle

= 5.36 X�= 5.36 There are 4 classes: prophase, metaphase, anaphase and telophase 4 - 1 = 3 degrees of freedom For biology, scientists use the 0.05; this is because they are 95% certain that the results are correct every time and that and 5% certain that the results are due to chance alone * If X� is greater in value than 7.82 then this means it is rejected by the null hypothesis. * If X� is lower in value than 7.82 then this means it is accepted by the null hypothesis. My result for x� is lower than 7.82, therefore my null hypothesis is accepted. My null hypothesis is correct. I do not have to change my null hypothesis Evaluation As there was a lot of equipment used, and a lot of people were doing the experiment in the same room at the same time, there was a possibility that something could go wrong along the way. In my practical, nothing really went wrong for me apart from one thing. I made 2 slides, my first slide, wasn't too good, there were air bubbles and small clumps of the root that hadn't been mashed up enough. ...read more.

Conclusion

and spindle fibres begin to form from the centrioles "� The centrioles are at opposite poles of the cell. � The pairs of homologous chromosomes (the bivalents), now as tightly coiled and condensed as they will be in meiosis, become arranged on a plane equidistant from the poles called the metaphase plate. � Spindle fibres from one pole of the cell attach to one chromosome of each pair (seen as sister chromatids), and spindle fibres from the opposite pole attach to the homologous chromosome (again, seen as sister chromatids)."(�) Anaphase Where the chromosomes are split at the centromeres and each chromatid is pulled apart, to the centrioles, by the spindle fibres "Metaphase sets the stage for chromosome separation in the next stage of mitosis: anaphase. Almost immediately after the metaphase chromosomes are aligned at the metaphase plate, the two halves of each chromosome are pulled apart by the spindle apparatus and migrate to the opposite spindle poles. The kinetochore microtubules shorten as the chromosomes are pulled toward the poles, while the polar microtubules elongate to assist in the separation. The photomicrograph above illustrates the early stage of anaphase where the chromosomes are just becoming completely separated. The microtubules are clearly visible in this complex" (4) Telophase This is where the nucleolus reforms and nuclear envelope also reforms around the chromatids. Spindle fibres brake away and disappear. ...read more.

The above preview is unformatted text

This student written piece of work is one of many that can be found in our AS and A Level Molecules & Cells section.

Found what you're looking for?

  • Start learning 29% faster today
  • 150,000+ documents available
  • Just £6.99 a month

Not the one? Search for your essay title...
  • Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

See related essaysSee related essays

Related AS and A Level Molecules & Cells essays

  1. Marked by a teacher

    Beetroot Practical Write up

    3 star(s)

    (It may be necessary to stagger the start time for each dilution to give you time to remove the cylinders at the end of the test) Stagger by 30 seconds. 6. Leave the cylinders in the boiling tubes for exactly 30 minutes 7.

  2. A Level Biology revision notes

    to their strong cellulose wall * Hypertonic: solution with a higher conc. of solutes / loses water by osmosis o Cells will shrink in hypertonic solutions (eg red blood cells) * Isotonic: solutions being compared have equal conc. of solutes o Cells which are in an isotonic solution will not

  1. Mint and Garlic

    Secondly, pipette the first concentration of caffeine to the water until a solution is formed. Then placing the sling under a microscope with a light shining on it time a ten second period in which the heart beat can be counted.

  2. Osmosis Coursework

    Due to the fact that water will always move from an area of higher potential to an area of lower water potential, the water will move from the plant cell to the solution. As a result, the plant cell will have lost water in the vacuole to the solution and

  1. Biology coursework

    of calcium chloride into a large beaker. I ensured that this beaker was thoroughly cleaned before I used it, using first tap water and then distilled water. This helped ensure there were no impurities in the beaker before I added the calcium chloride.

  2. Osmosis coursework

    of the high molecular velocities associated with the thermal energy of the particles. Diffusion theory The mean and variance function for discrete processes Let us consider the stochastic geometric growth model Nt+1 = tNt, or equivalently the random walk Xt+1 = Xt + St, where the t and St = lnt are independent with the same distribution.

  1. Applied Science

    beat; I multiplied it by three and got 75 beats per minute. This is good because her pulse rate is normal. And also indicate she is not suffering from any fever, fright, haemorrhage or illness. When I record my client pulse rate after 5 minute light exercise, it was 88 beats per minute.

  2. ENZYMES COURSEWORK

    The enzyme is antibacterial because it degrades the polysaccharide that is found in the cell walls of many bacteria. It does this by catalyzing the insertion of a water molecule at the position indicated by the red arrow. This hydrolysis breaks the chain at that point.

  • Over 160,000 pieces
    of student written work
  • Annotated by
    experienced teachers
  • Ideas and feedback to
    improve your own work