topic 2 - cells and control

state the stages of mitosis

1. interphase

2. prophase

3. metaphase

4. anaphase

5. telophase

6. cytokinesis

state what mitosis is required for

• growth

• repair

• asexual reproduction

explain what happens in interphase

• before mitosis

• nucleic DNA copies itself

• exactly

explain what happens in prophase

• DNA condenses

• chromosomes become visible

• nuclear membrane breaks down

explain what happens in metaphase

• chromosomes line up

• in the middle of the cell

explain what happens in anaphase

• spindle fibres

• split the the chromosomes down the centre

• pull on chromatid to either side of the cell

explain what happens in telophase

• new membranes form around the chromosomes

• at either side of the cell

explain what happens in cytokinesis

• cell cytoplasm and membrane divides

• to produce two genetically-identical daughter cells

• each new cell has a copy of each of the chromosomes

state the definition of growth

• permanent increase

• in size or mass

explain how mitosis is important in growth

• mitosis increases the amount of cells in the organism

• by producing two genetically-identical daughter cells

• increasing the amount of cells increases the mass of the organism

• causing growth

explain how mitosis is important in repair

• mitosis produces genetically-identical daughter cells

• which are used to replace

• old or damaged cells

explain how mitosis is important in asexual reproduction

• mitosis produced genetically-identical daughter cells

• this asexually reproduces genetic clones of the parent organism

state the definition of mitosis

• production of two daughter cells

• with identical sets of chromosomes in the nucleus to the parent cell

• resulting in two genetically-identical diploid daughter cells

state the definition of a cancer

• the result of changes to in cells

• that lead to uncontrolled cell division

state what is needed for growth in animals

• cell division

• cell differentiation

state what is needed for growth in plants

• cell division

• cell elongation

• cell differentiation

state what a specialised cell is

• cells that contain structural adaptations

• which enable them to perform

• specific functions

• within the organism

explain the importance of cell differentiation in the development of specialised cells

• active genes in cells determine cell function

• when the cell differentiates, the active genes cause

• the development and composition

• of sub-cellular structures

• to allow for specific cell functions to occur

explain how to use percentile charts to monitor growth

• find the child’s age on the x-axis

• find the child’s weight on the y-axis

• read across and up the growth chart lines

• to find the intersection point

• repeat this over a longer period of time during the child’s development

state what issues growth charts can find

• obesity

• malnutrition

• sudden changes in trend

• inconsistencies across different measurements

state the disadvantages of growth charts

• use historical data to create a growth chart

• historical events may have caused trends or differences in the data (e.g. global famine)

• don’t take into account ethnic differences in body composition and growth rates

describe the function of embryonic stem cells

• help to form

• all different tissues and organs

• needed for development

• to form a whole new individual

• can also differentiate to become any other type of body cell

describe the function of adult stem cells

• replace cells lost through damage

• produce new cells for growth

describe the function of meristem cells

• differentiate

• to promote plant growth