Paper 1 June 2021 Flashcards
(37 cards)
Name two pieces of laboratory equipment the student could have used to prepare
cells to view using a microscope
any two from:
* (microscope) slide
* cover slip
* dye / stain
* (mounted) needle
* pipette / dropper
* scalpel
* forceps / tweezers
What is the function of the coarse focus?
to focus (the image / cells)
Suggest one reason why the student could not see any cells when looking through the eyepiece
- no cells in the field of view
- slide not in the correct
position - mirror not in correct position
- (objective) lens not clicked
into place
or
(objective) lens dirty - (student is) looking at a
(large) air bubble - (the microscope is) not
focussed
Compare the structure of a red blood cell with the structure of a plant cell. (6)
Differences:
* red blood cell has no nucleus or plant cell has a nucleus
* red blood cell has no cell wall or plant cell has a cell wall
* red blood cell is a biconcave disc or there are many different
shapes of plant cell
* red blood cell contains haemoglobin or plant cells do not contain
haemoglobin
* red blood cells do not contain chlorophyll or plant cells (may)
contain chlorophyll
* red blood cell has no chloroplasts or plant cell has chloroplasts
* red blood cell has no (permanent) vacuole or plant cell has
(permanent) vacuole
* red blood cells are (much) smaller than plant cells
Similarities:
both have:
* cytoplasm
* cell membrane
* pigments (although they are different)
ignore references to mitochondria and ribosomes
When placed into a beaker of water:
* a red blood cell bursts
* a plant cell does not burst.
Explain why the red blood cell bursts but the plant cell does not burst.
water enters (the cells) by
osmosis / diffusion
plant cell has a cell wall (which
prevents it from bursting)
Describe two aseptic techniques the student should have used.
- sterilise equipment / surfaces
(before use) - (use) sterilised agar
- secure lid of the Petri dish
with (adhesive) tape - only lift lid of Petri dish a little
(when setting up plate)
or lift lid of Petri dish at an
angle (when setting up plate)
Which antibiotic is the least effective?
Give a reason for your answer.
it kills the fewest bacteria
or
it has the smallest area where
no bacteria were growing
Suggest one way the student could improve the investigation. (aseptic/disinfectant)
- repeat and calculate a mean
- repeat and eliminate
anomalies - use a control disc
- use different types of bacteria
Explain the financial impact on the UK economy of an increasing number of people
who are obese.
costs the NHS / UK health
service / Government / hospitals
more money
(because need to pay for)
additional surgery / medication /
hospital stay to treat stroke /
diabetes
or
more time off work (if in hospital
/ unwell) (1)
(so) employer / Government
have to give financial support (1)
A person who is obese is more at risk of arthritis.
Arthritis is a condition that damages joints.
Suggest how arthritis could affect a person’s lifestyle.
- movement issues
- loss of job / income
- disability
- mental health impact of lack
of movement
or
mental health impact of pain - need to visit the doctor / take
medication regularly - may need surgery
A person who eats a diet high in saturated fat might become obese.
Name two health conditions that might develop if a person eats a diet high in
saturated fat.
Do not refer to arthritis in your answer
type 2 diabetes
CVD / CHD
or
heart attack / disease
or
stroke
What is the chemical equation for aerobic respiration?
6O2 + C6H12O6 6H2O + 6CO2
Name the sub-cellular structures where aerobic respiration takes place.
mitochondria / mitochondrion
Energy is released in respiration.
Give two uses of the energy released in respiration.
- movement / muscle
contraction - keeping warm
- active transport
- building larger molecules
Describe two differences between aerobic and anaerobic respiration in humans.
Do not refer to oxygen in your answer.
- anaerobic produces lactic
acid and aerobic does not - aerobic produces carbon
dioxide and anaerobic does
not - aerobic produces water and
anaerobic does not - aerobic occurs (mainly) in the
mitochondria and anaerobic
does not - anaerobic releases less
energy than aerobic
What are the two products of anaerobic respiration in plant cells?
carbon dioxide
ethanol
A scientist investigated respiration and photosynthesis using some pondweed and a
pond snail. The apparatus was left in a well-lit room for 5 days.
The data logger recorded the concentration of carbon dioxide continuously.
After 5 days, the scientist completely covered the boiling tube with black paper.
The data logger continued to record the concentration of carbon dioxide.
Explain why the concentration of carbon dioxide in the tube stayed the same between
day 0 and day 5.
pondweed takes in CO2 for
photosynthesis
snail and pondweed are
respiring producing CO2
Suggest why the concentration of carbon dioxide increased between day 5 and
day 10.
(no light so) no photosynthesis
or
plant is not taking in CO2
and
snail and plant are respiring and
so are releasing CO2
On day 10, the pond snail died.
Explain why the death of the pond snail caused the concentration of carbon dioxide to
increase after day 10.
snail is being decayed /
decomposed / broken down
(by) decomposers / bacteria (in
pond water / snail)
(therefore) respiration (of
decomposers / bacteria)
releases CO2
Amylase is a polymer of smaller molecules.
Name the type of smaller molecule.
amino acid(s)
Name the three parts of the human digestive system that produce amylase.
salivary gland
pancreas
small intestine
Explain how amylase breaks down starch.
Answer in terms of the ‘lock and key theory’.
starch / substrate binds to active
site (of enzyme)
(because) shape of active site
and substrate are
complementary
a chemical reaction occurs to
produce smaller molecules
or
bonds between the (starch)
molecules are broken to
produce smaller molecules
Name two control variables the student used in the investigation.
- time before mixing (starch
and amylase) solutions - volume / 5 cm3 of starch
(solution) - volume / 1 cm3 of amylase
(solution) - volume / 1 drop of mixture
added to spotting tile - volume / 2 drops of iodine
(solution)
Why did the student leave the starch solution and amylase solution for 5 minutes
before mixing them?
to allow the solutions to reach
the same temperature as the
water
or
to allow both solutions to reach
5 °C
