Biology Flashcards
T or F mitochondria is present in eukaryotic cells but not in prokarytotic
true
How is a muscle adapted to its function
Muscle is adapted to bringing about movement as it contains protein filaments that slide over each other and cause contraction.
How are xylem vessels adapted to the transport of substances in the xylem
Xylem vessels are adapted to transport by having no end walls, and their side walls are thickened.
how do you set up a microscope on a high power
Focus on low power with the coarse adjustment, move the high power objective in line with the specimen, refocus on high power with the fine adjustment
what is an advantage of the transition electron microscope
higher magnifications are possible
If a cell called a megakaryocyte measures 1 x 10-4 m, and a neutrophil measures 1 x 10-5 m, what is the difference in order of magnitude?
1 as 5-4=1
how have microscopes developed over the years
increased resolution,increased magnification
t or f the magnification of an image is x1000 the actual size
true
If the actual size of a cell is 100 μm, and 10 cm in a book, what is the magnification of the image in the book?
1000
A type of white blood cell called a macrophage measures 5 x 10-5 m. What does it measure in micrometres?
50
what does 1 micrometer equal
10 -6m
What is the function of a ribosome?
protein synthesis
T or F digestion takes place along the alimentary canal
true
what is amylase
a carbohydrate that can break startch down into smaller molecules like glucose
where is amylase found
in your saliva
how are proteins digested
by protease enzymes
What are the different conditions in the stomach and small intestine
stomach has a ph of 2,small intestine has a ph of 8
what protein enzyme is used in the stomach
pepsin
What protein enzyme is used in your small intestine
trypsin
How are lipids digested
by lipases which turn it into glycerol and fatty acids
What is the name of the process in which lipids are digested
emulsification
what does emulsification do
breaks lipids into smaller droplets and these droplets have a larger surface area for the lipase enzymes to work on
Describe the 1st step of the test for the effect of ph on amylase
place a drop of iodine solution to each well of a spotting tile,get 3 testubes in the first add 2cm of startch solution,2nd add 2cm of amylase solution and in the 3rd add 2cm ph 5 buffer solution
What are buffer solutions used for
to control the ph
What is the 2nd step for the test on the effect of ph on amylase
place all 3 test tubes in a water bath at 30 degrees and leave it for 10 mins,then combine the 3 solutions into one test tube and stir it,return it to the waterbath and start a stopwatch
What is the 3rd step for the test on the effect of ph on amylase
after 30 seconds use the a rod to transfer a drop of solution to a well in the spotting tile which contains iodine,the iodine should turn blue-black showing that starch is present
what is the food test for starch
add food sample to the test tube,add a few drops of iodine solution to the food sample,if the sample contains starch it will turn blue-black
What is the 4th step for the test on the effect of ph on amylase
repeat the steps until the iodine remains orange,this tells us that starch is no longer present,repeat the experiment several time using different ph buffers
what is the food test for glucose
place a test tube into a water bath and leave it for 5 mins,add a few drops of benedicts solution if glucose is present the colour should change from blue to orange/brick red
what is the food test for proteins
get a test tube and place your food sample in it,add 2 drops of biuret solution if protein is present the colour will change from blue to purple
what is the food test for lipids
get your food sample in a test tube and add ethanol if lipids are present the solution will change from colourless to a cloudy emulsion
What should you do to the food samples before the food tests
use a pestle and a mortar to break up the food into small particles
what does the circulatory system do
transports nutrients and oxygen
What are the 3 main things the circulatory system relies on
blood,blood vessels,heart
in the circulatory system what does the deoxygenated blood do
carries blood from the heart to the lungs
in the circulatory system what does the oxygenated blood do
carries blood from the heart to the rest of the body
does the heart contain 4 chambers
yes
what are the top chambers of the heart called
an atria
what are the bottom chambers of the heart called
ventricles
what do valves do
prevent blood from flowing backwards
how does blood enter the heart
it goes in through the vena cava or the pulmonary vein
What is the 2nd stage of blood entering the heart
it flows into the right or left atrium
if blood is coming in from the vena cava would it be oxygenated or deoxygenated
deoxygenated
if blood is coming in from the pulmonary vein would it be oxygenated or deoxygenated
oxygenated
What is the 3rd stage of blood entering the heat
as the atriums contract the blood gets pushed into the ventricles
What is the 4th stage of blood entering the heart
as the ventricles contract blood gets pushed in either the pulmonary artery(lungs) or the aorta(rest of body)
where are pacemakers found in the heart
the right atrium
what do the pacemakers do to the heart
they send small electrical impulses to the muscles of the heart causing them to contract
what would happen if a pacemaker isn’t working properly
doctors can install an artifical pacemaker
how do artificaial pacemakers work
it has a wire that can carry electrical currents down to the heart,telling it to contract
what does an artery do
carries blood away from the heart
what does a vein do
carries blood to the heart
what do coronary arteries do
supplies muscles in the heart with all the oxygen and nutrients it needs
Why do multicellular organisms need a transport system?
To move molecules internally when the rate of diffusion would be too slow
T or F pulmonary circulation involves the collection of oxygen from alveoli in lungs
true
T or F red blood cells don’t have a nucleus
true
Which type of blood cell produces antibodies?
lymphocytes
where does the heart beat originate from
The heart beat originates in a group of specialised cells in the wall of the right atrium.
Describe 2 characteristics of a vein
Two characteristics of veins are that they have thin walls and a wide lumen.
What is a stent?
A stent is a tube of thin wire mesh that is used to keep a coronary artery open.
Wht should a patient do if there cholestral levels are to high
take a course of statins
An elite athlete’s cardiac output is measured as 35 dm3 per minute. If his measured heart rate is 180 beats per minute, what is his stroke volume?
194 cm3
how do you measure stroke volume
heart rate in beats per minute × stroke volume in cm3 per beat.
What sort of circulatory system is the human circulatory system?
a double circulatory system
What are the 3 blood vessels
arteries,capillaries,veins
what do capillaries do
exchange oxygen and nutrients with tissues
T or F blood insie arteries are at a very high pressure
true
describe the structure of arteries
strong and elastic,small lumen,2 layers
where does the blood go after the arteries
capillaries
describe the capillaries structure
very small,permeable,small lumen,surface area of all of them is huge,has a low blood pressure
What do the capillaries join on to
veins
Describe the structure of veins
large,big lumens,thin walls,blood carried is at a low pressure
what is the equation for calculating the rate of blood flow
amount of blood/time taken(minutes)
Individuals who have over what BMI are considered obese
30
t or f Some types of fat such as omega 3 and omega 6 fatty acids should be increased in the diet.
true
What type of diabetes can be controlled by dietary and lifestyle factors and is referred to as non-insulin dependent diabetes?
type 2
What vitamin aids the absorption of calcium and therefore helps reduce the risk of developing osteoporosis?
vitamin D
what is defiency amenia
A condition where the body lacks iron in the red blood cells, resulting in less oxygen being transported to cells.
Which health condition are post-menopausal women more at risk of developing due to losing bone mass rapidly?
osteoporosis.
A child should be breastfed or given fortified formula milk before the age of one to ensure they have enough of which nutrient?
iron
In order to maintain a healthy blood pressure, salt intake should be limited to how many grams per day?
6g
What is the medical term for high blood pressure?
hypertension
how do you calculate BMI
mass/height squared(m)
Calculate the BMI he weighs 140kg and his height is 192cm
140/1.92=38
In what case can the BMI chart be inacurrate
someone who has a lot of muscle could weigh a lot this is because muscle weighs more than fat,on the chart their BMI could come out as obese
What are the 4 factors that photosynthesis depends on
light intensity,temp,carbon dioxide,chlorophyll
What does chlorophyll do
absorbs light energy for photosynthesis
What are the reasons for a plant having less chlorophyll than another
diseases,lack of nutrients,enviromental stress
what relationship does light intensity have with photosynthesis
as light intensity increases so does the rate of photosynthesis but at a certain point it plateaus
What relationship does carbon dioxide have with the rate of photosynthesis
as carbon dioxide increases so does the rate of photosynthesis but at a certain point it plateaus
What relationship does temp have with carbon dioxide
first it initially rises but then it drops this is because the enzymes denature this happens at about 45 degrees
How do farmers increase the rate of photosynthesis in a colder climate with plants
put them in a greenhouse which traps the suns heat which increases the temp
What do paraffin heaters do and where is it used
pump carbon dioxide and releases heat this can be used in a greenhouse to increase the rate of photosynthesis
What do fertilisers do
provides plants with minerals
What produces amino acids from glucose
nitrates
What is a difference between plants adapted to sunny, and plants adapted to shady conditions?
The compensation point is lower in shade adapted plants than in plants adapted to sunny conditions.
What is the compensation point?
The compensation point is the light intensity at which the rate of photosynthesis is equal to the rate of respiration of a plant.
Which parts of the electromagnetic spectrum are absorbed by the chlorophyll molecule?
Red and blue parts
In an investigation on photosynthesis, why did a student add sodium hydrogencarbonate to the water?
as a source of carbon dioxide
How do you calculate the % in mass change
final mass-inital mass/initial mass x100
What can you conclude from the reverse osmosis potato experiment
the less amount of glucose and more time spent in the glucose solution resulted in the heaviest weight
HIV/AIDS is which type of disease
A virus
Salmonella is which type of pathogen
A bacterium
Rose black spot is which type of pathogen
A fungus
Malaria is caused by what type of pathogen?
A protist
What term describes an organism that transmits a disease?
A vector
How is measles often transmitted?
through the air
T or F skin is an example of a non-specific defence against disease
true
T or F lmphocytes produce antigens
false
How do we know that viruses are not alive
because they do not complete all of the seven life processes: Movement, Respiration, Sensitivity, Nutrition, Excretion, Reproduction and Growth.
Do viruses divide and reproduce
no
What symptoms can the norovirus cause
A common ‘upset tummy’ infection caused by a virus which is highly contagious.
What are the symptoms of Ebola
Often fatal disease caused by a virus which originated in Africa.
What does tobaco mocasiuis virus do
infects things like tomatoes and peppers,It infects the chloroplasts inside things making them change colour,crinkles the plants
What does HIV stand for
human immundefiency virus
How can HIV be transmitted
by bodily fluids,unprotected sex,injecting drugs through shared needles
What does AIDS stand for
acquired immune deficiency syndrome.
What are measles
An infectious disease of the respiratory system caused by a virus.
How are measles transmitted and what are the symptoms
It is transmitted through the air in tiny droplets after an infected person sneezes. It causes a fever and skin rash.
T or F measles can cause infertility in adults
true
T or F not all fungi causes diseases
true
Give an example of a fungi that does not cause disease
yeast
Give 2 examples of a fungal disease
athletes foot,rose black spot
What are the symptoms of athletes foot and how is it transmitted
causes dry,red,cracked or wet flaky skin,transmitted by touching infected skin or surfaces
What are the symptoms of rose black spot and how is it transmitted
It infects leaves leaving black spots and this reduces the plants ability to photosynthesize,it is transmitted through air or water
What are protists
a group of microorganisms that have features which belong to animals plants and fungi
T or F protists are all eukaryotic
true
T or F if something is eukaryotic it means it has a nucleus
true
What protist is malaria spread by
Plasmodium protists
What are mosquitos called when they transmit malaria
vectors
What is a vector
any organism that can spread a disease
What are the symptoms of malaria
fevers,sweats,chills,headaches
how can you decrease your chances of getting malaria
sleep under mosquitos nets,wear insect repellent
Describe xylem vessels
Narrow, hollow, dead tubes with lignin, responsible for the transport of water and minerals in plants.
Which tissue in the leaf absorbs the most light for photosynthesis?
Palisade mesophyll
Which tissue in the leaf is adapted for efficient gas exchange?
Spongy mesophyll
Which tissue transports water and minerals from the root to the leaves?
Xylem
Which tissue transports sugars from the leaves to other parts of the plant including roots for storage?
Phloem
Translocation is the movement of which substance?
sucrose in the phloem
Which cells control the stomata?
Guard cells
What sort of process is translocation?
active
What is the process which causes guard cells to become turgid?
osmosis
What is an adaptation of a root hair cell
Root hair cells have a large surface area for increased absorption of water.
T or F
The stomata of a desert plant are reduced in number and mainly closed to prevent water loss.
How do plants make their own sugars
through photosynthesis
What is translocation mainly used by
phloem cells
why do phloem tubes have pores in them
to enable the movement of cell sap
What is cell sap a mixture of
water and sugar
why is the sugar in the cell sap useful
can be stored as energy,used directly as energy
T or F phloem tubes can transport substances in either direction
true
Decsribe xylem tubes cells
hollow with no tubes and strenghtned by a material c
what are xylem cells jobs
transport water and mineral ions form the stem to the roots up to the leaves
what is water in a plant driven by
the evaporation from the leaves
why is the stomata always open
to let in carbon dioxide
Define the term transpiration
the evaporation of water from the leaves
What does transpiration stream mean
a chain of water molecules
What are the 4 factors that influence the rate of transpiration
light intensity,temp,air flow,humidity
What affect does light intensity have on the rate of transpiration
as theres lots of light more photosynthesis needs to happen so the stomata open to let more carbon dioxide in and so more water evaporates
what affect does temp have on transpiration
the warmer it is the higher rate of transpiration this is because the water molecules have more energy so they’re more likely to evaporate and diffuse out of the stomata
What affect does air flow being high have on transpiration
when it’s very windy the leaves are going to be blown away so the concentration gradient will be kept high which increases the rate of transpiration
What affect does humidity have on transpiration
when the air is more humid it will decrease the rate of transpiration
describe the process of plant organisation
similar cells to tissues to organs to organ systems
How do leaves get their water
from the soil it goes up the roots then up the xylem to the leaves
How does the carbon dioxide get into the leaves
it diffuses through the stomata
Where is the stomata mainly located
in the lower eperdermis
Where does the carbon dioxide go after it diffuses through the stomata
it goes into the spongey mesophyll
how is the spongy mesophyll adapted for carbon dioxide
lots of air space so it can diffuse into the pallisade mesophyll area
Where does most of the photosynthesis happen and why
in the pallisade mesophyll as it has lots of chloroplasts
What is above the palisade mesophyll
upper epidermis
What is the glucose transported through once photosynthesis is carried out
through the phloem
How does the leaf help minimise water loss
it has a waxy cuticle on top which stops the water from getting through
what is the waxy cuticle made up
a thin layer of lipids
Why is the stomata only open for a short amount of time
to maximise carbon dioxide diffusion and minimize water loss
How is each stoma adapted to maximise carbon dioxide diffusion and minimize water loss
each stoma is in between a guard cell when the water is coming out this will make the guard cells turgid,when there is not enough carbon dioxide the guard cells come together and this will trap the water vapour
How do guard cells conserve water when at night
when it’s night there is no photosynthesis happening so the guard cells close meaning no water can get out
Where is meristem tissue found
the growing roots of plants
what does meristem tissues do
they can differentiate into lots of different cell types so the plant can grow
T or FA gene is a short section of DNA that codes for a protein.
true
What is the job of specialised cells in the excretory system
Remove waste products and regulate the water content of the body
T or F Two daughter cells are produced when a cell divides by mitosis. Each has the same number of chromosomes as the parent cells.
true
What happens in the stage that is before mitosis in the cell cycle?
The stage before mitosis involves a period of growth, during which time DNA is checked for errors.
T or F Embryonic stem cells can differentiate into different cell types.
true
A scientist observes 100 cancer cells with a microscope. If 16 cells are undergoing mitosis, and the length of the cell cycle is 400 hours, what is the length of mitosis?
64 hours 16/100 X400
What is the calculation to calculate the length of mitosis
(number of cells undergoing mitosis X other bit of information which has a number)divided by the time length
What is an ethical consideration of stem cells
An ethical consideration about embryonic stem cell use is that embryos are being produced just so that stem cells can be extracted for research.
Where do plant cell stems occur
in meristems
Why are meristematic cells grown in a sterile culture medium?
Meristematic cells are grown in sterile culture media to avoid the growth of microorganisms.
What are guard cells in plants specialised to do?
Guard cells in plants are specialised to open and close to let carbon dioxide into the leaf for photosynthesis.
At what stage is each of the cells fate determined
the embryo stage
What can stem cells be used to repair or treat
damaged organs or bones they can treat new brain cells
What are the 2 types of stem cells
embryonic,adult
What are embroyonic stem cells
unspecialised cells that can develop into any type of cell
what are adult stem cells
unspecialised cells that can develop into most cells but not every
Where do adult stem cells come from
bone marrow
Where do embryotic stem cells come from
taken from unused embryos
How many patients in europe are treated with blood stem cells
26,000
what is theraputic cloning
cloning a patient using an embryo form the clone cells and then extracting the embryo to grow a specific organ for the patient
What is the argument against theraputic cloning
people don’t think it’s ok to mess with god
what can embryos also be developed into
flowers,roots,leafs
T or F embryonic cells are present in meristems
true
What is the process called which cells get their energy from
cellular respiration
How does our lungs supply oxygen to us
it transports the oxygen molecules into our bloodstream
Describe the process of oxygen enertering our body through our lungs
as we breathe in the oxygen goes down through the trachea from there it divides between our bronchi and then further divides between bronchioles it then reaches the alvoli
Alveoli is the site of ?
gas exchange
describe the structure of an alveolus
thin walls,walls are moist
Why is an alveolus adapted to have thin walls
it increases the rate at which carbon dioxide and oxygen can diffuse across
T or F alveoli has a very small surface area
false it has a very large
why is an alveolus wall made moist
it allows gases to dissolve which increases the rate of diffusion
is carbon dioxide carried by red blood cells
no it’s just dissolved around it
how do you calculate breathing rate
number of breaths taken/number of minutes
Which tissue layer of the leaf carries out most of the light absorption for photosynthesis?
palisade mesophyll
What causes the stomata to open?
when guard cells become turgid
What is the name of the process by which carbon dioxide and oxygen enter and leave the leaf?
gas exchange
what is carried in the phoelm vessels of the plant
sucrose
What is the loss of water vapour through the stomata called?
transpiration
What is a function of transpiration
Transpiration cools the leaf by the evaporation of water from the spongy mesophyll cells.
What is the name of the process in which water moves into the root hair cell?
osmosis
How are root hair cells adapted to maximise water absorption?
Root hair cells are long and thin to give a large surface area for maximum water absorption.
What two things are measured in a potometer to give an estimate of the rate of transpiration?
A potometer measures the distance the air bubble travels along the tube in a given time. The rate of transpiration is then estimated.
how many doses of antibiotics are prescribed each day
20
What is antibiotics
a group of drugs used to treat a disease caused by bacteria
Can antibiotics treat colds
no it can only treat diseases caused by bacteria
what was the first antibiotic created/discovered and who by
pencillin by alexander flemming
WHAT ARE THE 3 METHODS FOR MAKING ANTIBIOTICSS
Naturally,synthetically,semi-synthetically
What does it mean if an antibitotic is synthetic
it is made in a lab
What does it mean if an antibiotic is semi-synthetic
it takes naturally occuring antibitotics and uses additional lab work to add things like amino acids to it
Why do antibiotics not work against viruses
because viruses are not living organisms,so they don’t have metabolic processes that the antibiotics can distrupt
T or F bacteria is becoming resistant to antibiotics
true
Why are some bacterias resistant to antibiotics and why is it dangerous
some bacteria has a natural resistance to antibiotics and these can then reproduce and the ones they reproduce are also resistant
What is an antigen?
An antigen is a chemical on the surface of a pathogen.
How do vaccines protect people against disease infections?
Vaccines introduce pathogenic antigens, which cause white blood cells to produce antibodies.
What do antigens do
They stimulate the white blood cells to produce antibodies
How do antibiotics work?
Antibiotics damage bacterial cells and kill them.
Why do scientists grow bacteria in the laboratory?
Scientists grow bacteria in the laboratory to allow them to check the effectiveness of antibiotics or antibacterial substances at killing them.
Why do schools and colleges grow bacterial plates at 25 degrees Celsius?
The temp helps prevent harmful pathogens growing
What is a zone of inhibition?
Area where the growth of the bacteria has been slowed or stopped
How do you measure the size of the zone of inhibition?
pi radius squared
How are drugs checked for safety?
Drugs are tested for efficacy, toxicity and dosage.
What are the different stages of drugs trials?
Preclinical trials using cells, tissues and animals. Then clinical trials using healthy human volunteers and patients.
What type of drug trials are there?
The types of drug trials that exist are blind, double blind and open trials.
