Bioenergetics
Define metabolism
The sum of all the reactions that take place in the cell or body.
DOUBLE POINTS
Name the process in which root hair cells absorb water from the soil.
Osmosis
State the function of the arteries.
The arteries carry blood away from your heart to the organs of your body.
DOUBLE POINTS
Define placebo
A pill which does not contain the active drug. Often a sugar pill.
State the equation for percentage mass change. (Hint! Used in Osmosis practical with potato chips)
percentage mass change
= change in mass of potato/initial mass of potato x 100
State the equations for aerobic and anaerobic respiration
glucose -> lactic acid
Describe the difference between hypertonic and hypotonic solutions
Hypertonic solutions are more concentration than the cell contents.
Hypotonic solutions are less concentrated than the cell contents.
Describe the difference between a benign and malignant tumour.
A benign tumour is a growth of abnormal cells contained to one area. A malignant tumour invades neighbouring tissues and is harmful.
Name the scientist that started to use antiseptic chemicals to destroy pathogens before they caused infection.
Joseph Lister
In our Microbiology practical, we investigated the effect of antiseptics/antibiotics on bacterial growth. State the independent and dependent variables for this experiment
Independent - type of antibiotic
Dependent - zone of inhibition
What is hydroponics and why is it useful?
The water contains a perfect balance of nutrients to ensure maximum plant growth.
DOUBLE POINTS
What is 0.00051 written as standard form?
5.1 x 10-4
Name the equipment used to measure the rate of transpiration.
Potometer
The immune system can destroy pathogens in three main ways. State these three ways.
1. Phagocytosis (ingesting microorganisms)
2. Producing antibodies
3. Producing antitoxins
Describe the food test for protein, including what a positive result looks like.
Mix a small sample of food with Biuret solution. If the mixture goes a pale purple colour, the food contains protein.
DOUBLE POINTS
What is the glucose in photosynthesis used for? State two uses for full marks.
Any two from:
-fats and oil for storage (seeds)
-respiration
-combines with nitrate ions absorbed from soil for photosynthesis
-insoluble starch for storage in stems, leave and roots
-cellulose for cell wall
Describe the difference between prokaryotic and eukaryotic cells in terms of DNA.
Eukaryotic - DNA found in nucleus
Prokaryotic - single loop of DNA in cytoplasm and small loops of DNA called plasmids which code for antibiotic resistance
What is a communicable disease? Give one example with your definition.
A communicable disease is caused by pathogens and can be passed from one organism to another.
Examples: COVID-19, flu...
What are memory cells?
Some white blood cells are classified as memory cells. These cells remember the antibody needed to match the antigen and inactivate the pathogen.
DOUBLE POINTS
State two factors that can affect the activity of enzymes.
Temperature and pH
Describe one function of the liver.
Any from:
- Detoxifying poisonous substances (alcohol)
- Passing the breakdown products into the blood so they can be excreted in the urine via the kidneys
- Breaking down old red blood cells and storing iron until it is needed for new red blood cells
State the function of nerve cells and explain how they are adapted for their function.
Nerve cells are specialised to carry electrical impulses around the body of the animal.
Adaptations include: lots of dendrites to make connections between cells, long axons that carry the nerve impulses, synapses which use transmitter chemicals to pass impulses to other cells or between nerve cells
How is the upper epidermis of a leaf adapted for its function?
The upper epidermis is transparent so light can pass through to the palisade cells for photosynthesis.
Explain how protist pathogens cause malaria.
The protist pathogens are parasites that live and feed on other living organisms. Mosquitoes act as a vector of the disease. When the mosquito feeds on human blood the protist can then enter the human blood stream and damage red blood cells.
Why would it be better to use an LED light instead of a lamp in the photosynthesis practical?
LEDs work better as they don't give out as much thermal energy.