key info for exams

Question 1

Readings –

Answer 1

a value found from an instrument using a SINGLE judgement

Question 2

Measurements –

Answer 2

a value taken as the difference between TWO judgements

Question 3

You can take repeat readings/measurements but this can ? the uncertainty

Answer 3

reduce

Question 4

A statistical test helps us to suggest whether results are

Answer 4

significant, or just due to chance (non-significant).

Question 5

Statistical tests are used to analyse data mathematically You can be more ? in your ? if they are based on results than have been analysed using a statistical test.

Answer 5

You can be more confident in your conclusions

Question 6

A null hypothesis is a type of hypothesis used in statistics that proposes that

Answer 6

no statistical significance exists in a set of given observations.

Question 7

after the statistical test what do you need to decide for the null hypothesis

Answer 7

whether to accept or reject the null hypothesis

Question 8

what are the 3 statistical tests

Answer 8

Chi-squared
T-test
Correlation coefficient

Question 9

what’s the reason for choosing each statistical test:
Chi-squared
T-test
Correlation coefficient

Answer 9

Chi-squared - Comparing frequencies in different categories
T-test - Comparing means
Correlation coefficient -Looking for associations (correlations)

Question 10

If the probability of the results (the difference/ correlation) being due to chance is greater than 5% (p > 0.05) then the results are

Answer 10

not significant.

Question 11

If the probability of the results being due to chance is equal to or less than 5% (p ≤ 0.05), then the results are

Answer 11

significant

Question 12

If the probability of the results being due to chance is less than 1%, then we can be even more confident that the results are

Answer 12

significant

Question 13

if the result is significant it shows that its most likely not due to

Answer 13

chance

Question 14

When doing calculations using measurements given to a certain number of significant figures, you should give your answer to the

Answer 14

lowest number of significant figures that was used in the calculation.(taken from the question)

Question 15

3.7 cm3 min-1 to cm3 s-1

Answer 15

There are 60 s in 1 min so you need to divide by 60:

3.7 ÷ 60 = 0.062 cm3 s-1

Question 16

If you are given Standard Deviation ranges (in a graph or table) in an exam question, check if the ranges overlap.
If they do, then differences in the results are ?
If they do not, then differences in the results are ?

Answer 16

.
If they do, then differences in the results are not significant
If they do not, then differences in the results are significant

Question 17

A rate is

Answer 17

the change in a given period of time.

Question 18

on a tangent on a curved graph to calculate the maximum rate will be where the gradient is…

Answer 18

steepest

Question 19

mitotic index=

Answer 19

100x (number of cells in mitosis ÷ total number of cells)

Question 20

what’s end product inhibition

Answer 20

a type of enzyme inhibition where the product of an enzyme reaction inhibits its production in the metabolic chain of enzyme action https://cdn.savemyexams.com/cdn-cgi/image/w=1920,f=auto/uploads/2021/01/End-product-inhibition.png

Question 21

what is the genome.

Answer 21

The complete set of genes within a cell is known as the genome.

Question 22

what is the proteome.

Answer 22

The full range of proteins that a cell is capable of producing is known as the proteome.

Question 23

list the stages of the cell cycle and state which part is included in mitosis

Answer 23

I put my ass too close
Interphase
prophase - mitosis
metaphase- mitosis
anaphase - mitosis
telophase - mitosis
cytokinesis

Question 24

mitosis vs
meiosis

Answer 24

mitosis is a form of cell division which produces two identical, diploid body cells - 2 daughtercells
meiosis is a form of cell division which produces four non-identical, haploid sex cells or gametes (sperm and ova in humans) - 4 daughter cells

Question 25

Risks in microscopy

Answer 25

. Care must be taken when looking down the microscope if the illumination is too bright.
.Care must be taken when using microscope stains.
.Care must be taken when handling coverslips and microscope slides.

Question 26

how microscopes can be used to view slides(6 marks)

Answer 26

1.place the slide with the specimen and stain dye on the stage
2.select the lowest objective lens
3. move the stage up towards the lens
4.focus the slide using the( coarse) focussing knob
5. change the objective lens a more higher (greater) objective lens
6.repeat the focussing process( to make the image larger/ clearer) to increase the magnification/ resolution

Question 27

the term for ions’ concentration gradient is called?

Answer 27

electrochemical gradient

Question 28

Prophase

Answer 28

-The chromosomes condense (become shorter and thicker) and are now visible under a microscope.

-Centrioles (bundles of protein) migrate to opposite poles (sides) of the cell. Each centriole starts forming spindle fibres.

-The nucleolus disappears and the nuclear envelope starts to break down, leaving the chromosomes free in the cytoplasm.

Question 29

Metaphase

Answer 29

-The chromosomes line up at the equator (middle) of the cell.

-Each chromosome attaches to the spindle by their centromere.

Question 30

Anaphase

Answer 30

-The centromeres divide to separate each pair of sister chromatids.

-The spindle fibres contract and shorten to pull the chromatids to opposite poles of the cell.

-Each chromatid is pulled by its centromere, causing them to take on a ‘V’ shape when viewed under a microscope.

Question 31

Telophase

Answer 31

-The chromatids reach the opposite poles of the cell where they uncoil to become long and thin chromosomes again.

-A nuclear envelope forms around each set of chromosomes to form two nuclei and the nucleolus starts to reform.

Question 32

Cytokinesis

Answer 32

-After the steps of mitosis, the cytoplasm divides in a process known as cytokinesis. This produces two daughter cells that are genetically identical to one another.

Question 33

is cytokinesis part of mitosis

Answer 33

nope it’s another part of the cell cycle

Question 34

Interphase

Answer 34

• Cell growth - This includes an increase in cytoplasm.
• Synthesis of proteins - These proteins are used to replicate organelles.
• Replicating DNA - This results in double the genetic material.

Question 35

Food travels through the alimentary canal in the following order:

Answer 35

Mouth ➔ oesophagus ➔ stomach ➔ small intestine ➔ large intestine ➔ rectum ➔ anus

Question 36

alimentary canal

Answer 36

the whole passage along which food passes through the body from mouth to anus during digestion.

Question 37

physical digestion -

Answer 37

The break down of large food pieces into smaller ones to increase the surface area for chemical digestion.

Question 38

Chemical digestion -

Answer 38

Enzymes catalyse hydrolysis reactions that break bonds in large insoluble molecules to form smaller soluble molecules.

Question 39

The key components involved in digestion include: ( 8 steps)

Answer 39

Salivary glands - These secrete saliva containing amylase.

Oesophagus - This transports food to the stomach.

Stomach - This digests food (especially proteins) and produces acid to destroy pathogens.

Liver - This produces bile salts to aid lipid digestion.

Pancreas - This secretes pancreatic juice containing enzymes (proteases, lipases, and amylases).

Small intestine - This has three parts (you only need to know the last part, the ileum) that are the site of further digestion and absorption.

Large intestine - This absorbs water and stores waste.

Rectum - This stores faeces before removal via egestion through the anus.

Question 40

The ends of the DNA strand are called the

Answer 40

5’ end (said as “5 prime end”) at the phosphate end, and the 3’ end at the deoxyribose end.

Question 41

The two strands of DNA are antiparallel which means

Answer 41

that one strand runs in a 5’ to 3’ direction and the other runs in a 3’ to 5’ direction.

Question 42

Some proteases are produced by :

Answer 42

stomach, pancreas and the epithelial cells lining the ileum

Question 43

Some proteases act in :

Answer 43

small intestine and stomach

Question 44

lipases are produced in:

Answer 44

pancreas

Question 45

lipases act in:

Answer 45

the small intestine

Question 46

maltase is produced by

Answer 46

epithelial cells in in the ileum lining and some are even bound here

Question 47

carbohydrase are produced by:

Answer 47

salivary glands, the pancreas, and the epithelial cells lining the ileum.

Question 48

in bio Degenerate means

Answer 48

an entity performs the same function or produces the same output as a structurally-different entity does. e.g. More than one codon codes for a single amino acid;

Question 49

Buffers are

Answer 49

solutions that resist any slight change in pH/ temperature

Question 50

Absorption of triglycerides (7)

Answer 50

-Triglycerides and other lipids are broken down into monoglycerides (like glycerol) and fatty acids, and form micelles with bile salts.
-Micelles are broken down to release fatty acids and monoglycerides.
-As they are both non-polar, fatty acids and monoglycerides can diffuse into the epithelial cells that line the ileum.
- Triglycerides reform inside the cells’ endoplasmic reticulum.
- Triglycerides are packaged into chylomicrons for transport.
- Chylomicrons are released from the epithelial cells by exocytosis into lacteals, which are lymphatic vessels in the villi.
- Chylomicrons are transported via lymph vessels in the lymphatic system to the blood.

Question 51

Time taken for total division / no. Generations =

Answer 51

Generation time( time for 1 generation division

Question 52

an appropriate no. signifcant figures when asked in an exam

Answer 52

3 significant figures.