Yr 11 January Exams Flashcards
What is the structure of a plant cell?
- nucleus
- cell membrane
- cell wall
- vacuole
- chloroplasts
- cytoplasm
- nuclear membrane
What is the structure of an animal cell?
- nucleus
- membrane
- cytoplasm
- nuclear membrane
What is the equation for magnification?
Magnification = Observed Size
—————– OR Objective Lens X Eye lens
Actual Size
Structure of Bacterial cells?
- loop of DNA
- plasmids
- cell membrane
- non cellulose cell wall
- cytoplasm
Do Bacterial Cells contain chromosomes?
No
Animals grow evenly throughout the body. Plants don’t, they grow in regions called….?
Apices
What are stem cells?
Very simple and undifferentiated cells in found in young animal embryos
How to get micro metres?
Mm divided by 1000
What are the levels of organisation in organisms?
Cells - Tissues - Organs - Organ Systems - Organism
What does selectively permeable mean?
Some substances can pass through but others can’t
What does fully permeable mean?
All substances can pass through
What is diffusion?
When molecules in a region of high concentration move to an area of low concentration
Name the 3 factors which affect the rate of diffusion?
- size of molecules
- temperature of substance
- concentration gradient
Why do you place the leaf in boiling water in a starch test to see if light is needed for photosynthesis?
To kill the leaf and stop chemical reactions
Why do you boil the leaf in ethanol in the starch test to see if light is needed for photosynthesis?
To remove the green pigment, chlorophyll
Where does photosynthesis occur in plant cells?
The chloroplasts
Word equation for Photosynthesis?
Chlorophyll
CO2 + Water ———–> Glucose + Oxygen
Light
How do carbon dioxide and oxygen enter and leave the leaf?
Carbon dioxide enters the stomata and diffuses in the small air spaces in to the palisade mesophyll layer. Photosynthesis occurs and oxygen leaves through the stomata through diffusion.
Do stomata stay open all day and night?
No, the guard cells change shape and close the stoma during the night
How is the leaf adapted for light absorption?
- short distance between bottom and top of leaf so all cells receive light
- large surface area
- transparent waxy cuticle
- palisade mesophyll is tightly packed with tall thin cells
Word equation for respiration?
Glucose + Oxygen —-> CO2 + Water + Energy
Name the 3 things the products of photosynthesis can be used for?
- respiration
- storage
- growth
In some experiments to prove carbon dioxide is needed for photosynthesis, what chemical would they add in a flask with a leaf in it?
Sodium Hydroxide ( Soda Lime ) which removes CO2
Higher light intensity _________? the rate of photosynthesis
Increases
Higher temperature decreases rate of photosynthesis. True or False?
False
Higher CO2 increases the rate of photosynthesis. True or False?
True
What is the compensation point?
Where both rates of respiration and photosynthesis are equal
When does the compensation point naturally occur?
Dusk and Dawn
Hydrogen Carbonate indicator is red. When CO2 levels increase, what colour does it turn?
Yellow
Hydrogen Carbonate is red. When CO2 levels decrease, what colour does it turn?
Purple
How to calculate energy in food?
Mass of water (g) X temp. rise (°C) X 4.2
Energy (J) = ———————————————
Mass of food sample (g)
How to calculate amount of Vit C in fruit juice sample?
Volume (ml) standard ascorbic acid solution X 1%
Vitamin C (g) = ——————————————————–
Volume (ml) of fruit juice sample
What is BMI?
Body Mass Index ratio
Height in metres squared
What is your BMR?
Basal Metabolic Rate, a measure of minimum energy expenditure when someone is inactive.
How to calculate number of calories needed to maintain current weight?
BMR X Activity Levels
Name the 3 main functions of food?
- energy
- growth and repair
- protection
Name the 7 main nutrients?
- carbohydrates
- fats
- proteins
- fibre
- water
- vitamins C + D
- minerals
What elements are present in Carbohydrates, Fat and Fibre?
- Carbon
- hydrogen
- oxygen
What elements are present in protein?
- Carbon
- hydrogen
- oxygen
- nitrogen
1g protein gives?
1g fat gives?
1g fat gives?
- 17kJ
- 38kJ
- 17kJ
Energy requirements depend on what 3 factors?
- age
- gender
- activity levels
Name reagent for starch test?
Iodine
Name reagent for Benedict’s Test?
Benedict’s Solution
Name reagent for Buirets Test?
A mixture of copper sulphate and sodium hydroxide
What does Buirets test, test for?
Protein
Reagent for Emulsion test?
Ethanol
What does Emulsion test, test for?
Fat
Name reagent for DCPIP test?
DCPIP
What does DCPIP test, test for?
Vitamin C
What colour does iodine turn when starch is present?
From yellow/brown to Blue/black
What colour does Benedict’s solution turn when sugar is present?
Blue to green to orange to Brick Red Precipitation
What colour does Buirets test reagent turn when protein is present?
Blue to Purple
What colour does ethanol turn when fat is present?
A white emulsion forms at top of solution
What colour does DCPIP turn when Vitamin C is present?
From blue to Pink to colourless
Name 6 health problems caused by poor diets?
- obesity
- heart disease
- stroke
- arthritis
- high blood pressure
- diabetes
What is digestion?
The breaking down of large insoluble molecules in to smaller soluble molecules
What is ingestion?
Taking food in to the alimentary canal through the mouth
What is absorption?
The passage of small soluble molecules along the wall of the intestine in to the blood stream
What is Assimilation?
Digested food molecules absorbed in to cells
What is egestion?
When undigested food passes out of the anus
What two types of digestion occur when food enters the mouth?
Physical and Chemical
How does chewing help digestion?
Breaks up food, increasing surface area for enzyme action