Biology Flashcards
O 1. 1 Name two pieces of laboratory equipment the student could have used to prepare
cells to view using a microscope.
Cover slip
Forceps
The student tried to look at the cells using the microscope.
Suggest one reason why the student could not see any cells when looking through part A.
Slide was not on properly
Red blood cells are specialised animal cells.
Compare the structure of a red blood cell with the structure of a plant cell.
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
• cel memorane
• pigments (although they are different)
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 by osmosis but plant cell has a cell wall prevents from bursting
Bmi category of person A
Normal
92/1.71^2
31.5
Two patterns shown in table 2 about the effects of bmi category
The higher the bmi the lower the number of years living in good health
The higher the bmi the higher the number of years living bad health
Explain the financial impact on the UK economy of an increasing number of people
who are obese.
Costs the nhs money as they need to pay for additional surgery
Suggets how arthritis could affect a perosns lifestyle
Movement issues
Loss of job
Two health conditions that might develop if a person eats a diet high in saturated fats
Type 2 diabetes
Heart attack
Aerboic reperwtion formula
602+c6h12o6->6h20+6co2
Name the sub celluear structure where anerobic repsiration takes place
Mitochondrai
Give two uses of the energy realsed in reperation
Muscle contraption
Keeping warm
DqlqName the sub celluear structure where anerobic repsiration takes place
Mitochondrai
Two differnces betweeen anerobic and aerboic repsiration
Anerboic produces latic acid areboic dies not it
Aerboci produces carbon dioxide and anerobic does not
Two products of anerobic reperation in plant cells
Carbon dioxide
Ethanol
Explain why the co2 conc in the tube stayed the same between day 0-5
Pond weed taked in c02 fir photosythenis
Snail and pond weed are repiring producing c02
Suggets why the conc of c02 increased between day 5 and day 10
Plant not taking in co2
Explain why the death of the pond snail caused thr conc of co2 to increase after day 10
Snail is decomposed by bacteria therfore reperation of bacteria reales co2
Amayalse is a polymer of samller molecules name it
Amino acids
Name three parts of the human digersive system that produce amyalsse
Salivary gland
Pancreas
Small intestine
Explain hwo amylase break down starch lock and key theory
Substarte binds to active site because shape of active site and substarte are perfect as they fit this leads to a chemical reaction occurs to produce smaller moeclues
Activity of amylase two control variables
Time before mixing
Volume of starch
Why did the student leave the starch soloution and amyalse soloution for 5 minutes before mixing them
To allow both solution to reach 5 degrees
Cocnlusions can be made about effect iif temp on amylase activity between 20 and 65 degrees
As temp increases activity increases to 35 degrees after acriviry decerases
Explain the results at 5 degrees and at 80 degrees
Iodine not yellow brown as starch is still presnet at 5 defrees amylase have low kinetic energy therefore fewer collision at 80 degrees amylase become denatured so starch no longer fits
Describe how student could extend the investigation to determine effect of a differnt factor on amyalse activity
Keep temp constant but change named factor and test a range of values of named factor
Cross section of leaf what cell most trasnparent
A
Which cell structure in a leaf mesophyll cell is not found in a root hair cell
Chloroplasts
Name the cells in a leaf that controlls the rate of water loss
Guard cells
Sceninfic term decribe the movement of water for leaves
Transpiration stream
Which cahnge would decrease the rate of water loss from plants leave
Increased humidity
Compare the structure of xylem tissure an dphilem tissue
xylem is made of dead cells and
phloem is made of living cells
• phloem cells have pores in their end walls
and
xylem cells do not have pores in their end walls
• xylem is hollow or xylem does not contain cytoplasm and
phloem contains cytoplasm
• xylem contains lignin and
phloem does not (contain lignin)
• both made of cells
• both tubular
Function
• xylem transports water / mineral ions
and
phloem transports (dissolved) sugars
• xylem is involved in transpiration and
phloem is involved in translocation
• xylem transports unidirectionally and
phloem transports bidirectionally
• both transport liquids / substances throughout the stem / leaves / roots / plant
Determine the rate of water losss at 12 use tangent
40/7=5.71 covert to min equals 9.5x10^-2
The rate of water loss at midnight was much lower at 12
Stomata are closed because there is less light
Describe what happens to cells when a turmor forms
Cells grow uncontrollably
Evidence shows that tunir in the lung is malignant
Has spread to other parts
Some types of cancer can cause the numbers of blood components in a person’s
body to fall to a dangerously low level.
A person with one of these types of cancer may experience symptoms such as:
• tiredness
• frequent infections
• bleeding that will not stop after the skin is cut.
[Question]
Explain how a very low number of blood components in the body can cause these symptoms.
Tiredness
• fewer red blood cells
• so less haemoglobin
• so less oxygen transported around the body
• so less (aerobic) respiration can take place
• so more anaerobic respiration takes place
• less energy released for metabolic processes or less energy released so organs cannot function as well
• lactic acid produced (during anaerobic respiration) causes muscle fatigue
Frequent infections
• fewer white blood cells / phagocytes / lymphocytes
• so fewer antibodies produced or less phagocytosis
• so fewer pathogens / bacteria / viruses killed
Bleeding
• fewer platelets
• so blood does not clot as easily
It is dangerous for a patient with blood group A to receive red blood cells from a donor with blood group B.
Explain why.
Anti b antibioticx in patient will bind to type b antigens on perosns red blood cells so red blood cells clum together and block capilleres so cells cant respire
Explain why blood group o red blood cells can be given to patients with any blood group
No antigens so antibiotics cannot bind to the antigens
Risk lowest prob of occuring
Heptais c infection
A person has a tumour blocking the tube leading from the gall bladder to the
small intestine.
Explain why this person would have difficulty digesting fat.
Less bile reaches small intetsine so less fat so smaller surface area for lipase to break down fat ph of small intetsine is not neturailsed so lipase is not at opitim ph to breka down fat
Describe how energy for the photosynthesis reaction is gained by plants.
Light is captured and absorbed by chlorphyll
Molecules of carbon dioxide diffuse from the air into the mesophyll cells.
Which two changes will increase the rate at which carbon dioxide diffuses into the mesophyll cells?
Increased co2 conc in the air
Increased number of stomatoa that are open
Explain how the human lungs are adapted for efficient exchange of gases by diffusion.
Indicative content (many) alveoli
• provide a large(r) surface area : volume)
cabillaries are inin
or alveoli/ capillary walls are thin or one cell thicK or capillaries are close to the alveoli
• which provides short diffusion path (for oxygen / carbon dioxide)
• breathing (mechanism) moves air in and out or lungs are ventilated
• to bring in (fresh) oxygen
• to remove carbon dioxide
• to maintain a concentration / diffusion gradient
large capillary network (around alveoli) or good blood supply
• to remove oxygenated blood) quickly
• to bring carbon dioxide to the lungs quickly
• to maintain a concentration / diffusion gradient
Two similarties between prokraytic cells and eyokratytic cells
Both have ribsomes and cytpplasm
3 differnces betweeen prokraytic. And eyokraytic cells
Prokraytic cells is smaller
Prokyaric cell ahs no nuckeus
Has no mitochondrai
What happens during each stage of cell cycle
(stage 1)
DNA / chromosomes replicate / duplicate
mitochondria / ribosomes / sub-cellular structures increase in number
or mitochondria / ribosomes / sub-cellular structures replicate
(stage 2)
one set of chromosomes is pulled / moved to each end of the cell
(stage 3)
the cytoplasm and cell membrane divides (to form two cells)
Two products formed when lipids are broken down
Fatty acids
Gylcerol
