2021 PAPER AS Flashcards
what two monosaccharides make up sucrose
a-glucose and fructose
what is atrial fibrillation?
when the atria beats more frequently than the ventricles-> no clear P wave present
what are the cellular functions of the cytoskeleton
-form spindle fibres to move chromatids during mitosis and meiosis
-mechanical strength to cells
-cell support/ stability/ maintains shape
-movement of organelles OR holding organelles into position
-formation/ movement of cilia/flagella
-cell movement/ endocytosis/ exocytosis/ phagocytosis/ cytokinesis
what are ways in which tubulin is essential to protein synthesis and protein secretion in eukaryotic cells
-movement of mRNA from nucleus to ribosome
-movement of vesicles from RER to golgi
-movement of polypeptides through RER
-movement of secretory vesicles from golgi to cell surface membrane
explain how to measure the diameter of the nucleus of one white blood cells, when observing the cells through a light microscope
-use an eyepiece graticule
-calibrate graticule using stage micrometre (calc length of one eyepiece division)
- measure the nucleus in eyepiece units/ graticule units
-take repeat measurements and calculate a mean diameter
-use calibrated eyepiece unit to calculate the diameter (of nucleus in um)
what is the max res of a laser scanning confocal microscope
200nm
what is the max res of a SEM
3-10nm
what is the max res of a TEM
0.2nm
what is the image colour of a laser scanning confocal microscope
coloured
how can you tell if a cell has stopped dividing at the G2 checkpoint
-no visible chromosomes
-nuclear membrane present
-more DNA/ larger nucleus
-larger number of named organelles
when an enzyme is added to break down DNA, what enzyme should be used
a protease enzyme should be used because protease enzymes break down histones/ proteins associated with DNA
explain why using standard deviation error bars would increase the confidence in a conclusion made when comparing heights of males and females
-standard deviation shows the spread of data compared to the mean
-standard deviation reduces the effect of an anomaly (in data)
when selecting male and female participants to measuring mean resting volume, what are ways in which validity could be increased
-increasing the sample size
-random selection of participants
-select participants who are rested
-sample to include a range of fitness/ height size/ build
- equal number of boys and girls
- equal numbers in each age group
why as year increases so does percentage of blood samples being methicillin resistant increase
-greater use of methicillin
-not completing course of methicillin
-use of methicillin in farming
-natural selection of MRSA
-large % increase (in short time) due to fast regeneration time
explain the importance of maintaining biodiversity for the discovery of new antibiotics
-many drugs found in/originated from plants/microbes
-so maintaining biodiversity increases the chance of finding/ developing new drugs
-maintains a genetic resource for the future
-once a species is extinct, its gone forever
