AS

Question 1

What is a tissue

Answer 1

similar cells that work for a common function

Question 2

why is a piece of xylem tissue dyed before its put under a microscope for 30 mins

Answer 2

to allow time for the dye to travel through and stain the xylem

making the xylem visible under the microscope

Question 3

What stage of interphase is DNA replicated

Answer 3

S phase

Question 4

how do cells process a polypeptide and secrete it as an enzyme

Answer 4

Polypeptide is folded in the eough endoplasmic recticulum RER

packaged into vesicles, then transported to fuse with the Golgi apparatus

A polypeptide is modified within the Golgi apparatus

Exocytosis happens, and the vesicles fuse with the cell surface membrane

Question 5

Why are captive breeding programs important for maintaining biodiversity

Answer 5

increases the population size of the species

maintains genetic diversity

Therefore, prevent the extinction of species

Question 6

A mother bear has 2 babies. Why aren’t the babys alowed to remain in the same zoo

Answer 6

prevent related animals from breeding

prevent inbreeding depression

increase genetic variation within the offspring

Question 6

describe the structure of a cellulose microfibril

Answer 6

Cellulose is made up of β-glucose

glucose monomers are held together by glycosidic bonds

Beta glucose monomers form long straight chains

Cellulose molecules are held together by hydrogen bonds

microfibrils are composed of many cellulose molecules

Question 7

Conduct an investigation to provide evidence that there is a correlation between fibre diameter and tensile strength

Answer 7

{extract / select} fibres with a range of diameters including
fibres less than 0.09mm (1)

make sure length of fibre is kept the same

attach fibres to clamp stands and add masses until fibre
breaks (1)

repeat and calculate a mean (1)

describe how to calculate tensile strength by dividing force by
cross sectional area (1)

plot values on a graph to establish if there is a correlation