key info for exams Flashcards
Readings –
a value found from an instrument using a SINGLE judgement
Measurements –
a value taken as the difference between TWO judgements
You can take repeat readings/measurements but this can ? the uncertainty
reduce
A statistical test helps us to suggest whether results are
significant, or just due to chance (non-significant).
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.
You can be more confident in your conclusions
A null hypothesis is a type of hypothesis used in statistics that proposes that
no statistical significance exists in a set of given observations.
after the statistical test what do you need to decide for the null hypothesis
whether to accept or reject the null hypothesis
what are the 3 statistical tests
Chi-squared
T-test
Correlation coefficient
what’s the reason for choosing each statistical test:
Chi-squared
T-test
Correlation coefficient
Chi-squared - Comparing frequencies in different categories
T-test - Comparing means
Correlation coefficient -Looking for associations (correlations)
If the probability of the results (the difference/ correlation) being due to chance is greater than 5% (p > 0.05) then the results are
not significant.
If the probability of the results being due to chance is equal to or less than 5% (p ≤ 0.05), then the results are
significant
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
significant
if the result is significant it shows that its most likely not due to
chance
When doing calculations using measurements given to a certain number of significant figures, you should give your answer to the
lowest number of significant figures that was used in the calculation.(taken from the question)
3.7 cm3 min-1 to cm3 s-1
There are 60 s in 1 min so you need to divide by 60:
3.7 ÷ 60 = 0.062 cm3 s-1
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 ?
.
If they do, then differences in the results are not significant
If they do not, then differences in the results are significant
A rate is
the change in a given period of time.
on a tangent on a curved graph to calculate the maximum rate will be where the gradient is…
steepest
mitotic index=
100x (number of cells in mitosis ÷ total number of cells)
what’s end product inhibition
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
what is the genome.
The complete set of genes within a cell is known as the genome.
what is the proteome.
The full range of proteins that a cell is capable of producing is known as the proteome.
list the stages of the cell cycle and state which part is included in mitosis
I put my ass too close
Interphase
prophase - mitosis
metaphase- mitosis
anaphase - mitosis
telophase - mitosis
cytokinesis
mitosis vs
meiosis
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
Risks in microscopy
. 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.
how microscopes can be used to view slides(6 marks)
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
the term for ions’ concentration gradient is called?
electrochemical gradient
Prophase
-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.
Metaphase
-The chromosomes line up at the equator (middle) of the cell.
-Each chromosome attaches to the spindle by their centromere.
Anaphase
-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.
Telophase
-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.
Cytokinesis
-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.
is cytokinesis part of mitosis
nope it’s another part of the cell cycle
Interphase
- 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.
Food travels through the alimentary canal in the following order:
Mouth ➔ oesophagus ➔ stomach ➔ small intestine ➔ large intestine ➔ rectum ➔ anus
alimentary canal
the whole passage along which food passes through the body from mouth to anus during digestion.
physical digestion -
The break down of large food pieces into smaller ones to increase the surface area for chemical digestion.
Chemical digestion -
Enzymes catalyse hydrolysis reactions that break bonds in large insoluble molecules to form smaller soluble molecules.
The key components involved in digestion include: ( 8 steps)
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.
The ends of the DNA strand are called the
5’ end (said as “5 prime end”) at the phosphate end, and the 3’ end at the deoxyribose end.
The two strands of DNA are antiparallel which means
that one strand runs in a 5’ to 3’ direction and the other runs in a 3’ to 5’ direction.
Some proteases are produced by :
stomach, pancreas and the epithelial cells lining the ileum
Some proteases act in :
small intestine and stomach
lipases are produced in:
pancreas
lipases act in:
the small intestine
maltase is produced by
epithelial cells in in the ileum lining and some are even bound here
carbohydrase are produced by:
salivary glands, the pancreas, and the epithelial cells lining the ileum.
in biology Degenerate means
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;
Buffers are
solutions that resist any slight change in pH/ temperature
Absorption of triglycerides (7)
-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.
Time taken for total division / no. Generations =
Generation time( time for 1 generation division
an appropriate no. signifcant figures when asked in an exam
3 significant figures.
amylase hydrolyses starch into what disaccharide
maltose
Reducing sugars include:
Reducing sugars include:
all monosaccharides and lactose and maltose
When standard deviation errors bars overlap quite a bit, it’s a clue that the difference is…
not statistically significant and is more likely due to significance.
scroll down to overlapping
standard deviation diagram https://www.biologyforlife.com/interpreting-error-bars.html
