topic 2 - cells and control

state the stages of mitosis

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

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

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