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