Exmapro questioms

the scientists breaking open the cells and organelles using a detergent that dissolves lipids in water ? How

• cell membrane made from phospholipid

• Dissolves phospholipid bilayer

Describe how the scientists produced a calbration curve and how they would use the calibration curve to find the concentration of protein in the blood plasma ?

• produce known concentrations of Protein

• Measure absorbance of each concentration

• Plot a graph absorbance y axis and concentration x axis and draw curve

Describe how he should collect and process data from these 2 seeds to investigate whether there is a difference in seed size between these 2 populations of trees

• use random sample of seeds

• Use large enough sample to representative

• Calculate mean and standard deviation

Describe how substances move across cell membrane by facilitated diffusion

• carrier proteins

• Attach to specific substances

• Moved against a concentration gradient

Describe the behaviour of chromosomes during mitosis and explain how this results in the production of 2 genetically identical cells ? 7 marks

• chromosomes shorten

• Chromosomes each two identical chromatids

• Chromosomes move to equator of cell

• Attach to individual spindle fibres

• Centromere divides

• Sister chromatids move to opposite poles

• Each pole receives all genetic information

• Nuclear envelope forms around each group of chromosomes

Apart from an increase in the amount of DNA give one process which occurs during stage X which enables nuclear division to occur ?

• atp prodution

Give one piece of evidence from the table which indicates that these cells are multiplying rapidly ?

• short duration of interphase

Name 2 things present on an epithelial cell that not present in bacteria cell

• nucleus

• Microvilli

What does mitochondria do and help with absorption?

• site of aerobic respiration

• Provided ATP

• move substrates against their concentration gradient

Why Is it that if the most of the mitochondria is faulty and dies it prevent many enzyme catalysed reactions to stop

• less atp produced

• Nor enough atp for enzyme action

describe how a sample consisting of only chloroplast can be obtained from homogenised vell tissue

• spin at low speed to remove the nucleus

• supernatant re-spin at a higher speed

• identifying chloroplast through a microscope

suggest how the proportion of dividing cells in a thin section should be determined?

• count cells using micrscope

• count no of cells in cells division and then total number of cells in field of view

why is it important the same variety of barely used?

• confounding variable

• so genetically similar

what is the role of centro mere in mitosis?

• holds chroamtids togather

• attaches chromatids to the spindle

• allows chromatids move to opposite poles

which tissue is cancerous from table?

d

• because lowest % of cells in inter phase

• so more cells dividing

how we could recgonise cells were in the interphase?

• no visible chromosomes