8G Ecosystems Flashcards
Name 2 things energy can be used for in your body.
To contract muscles, to keep your body temperature at a suitable level and to grow.
How do animals obtain energy?
Energy is released during respiration when glucose reacts with oxygen
What is the name of the chemical reaction that occurs in all of our body cells?
Respiration.
What is the word equation for the process of respiration?
Oxygen + glucose -> Carbon dioxide + water
What is required for aerobic respiration?
Glucose and oxygen
What happens to the waste products of respiration?
Diffuse into the blood and exhaled through the lungs.
What are the small building blocks of proteins?
Amino acids.
Name a carbohydrate found in plants.
Cellulose
When do athletes need to work without oxygen?
When they sprint or weightlift
What is the name for respiration without oxygen?
Anaerobic respiration.
What is the equation for this form of respiration?
Glucose -> lactic acid
Which type of respiration is more efficient?
Aerobic respiration.
What are the consequences of a build-up of lactic acid?
Muscle fatigue or cramp
What is an ‘oxygen debt’?
The amount of oxygen required to break down lactic acid.
In what 3 forms can energy be stored in animals?
Glycogen in muscles, glycogen in the liver and fat reserves.
What can the body use as a last resort for energy when all the glucose and stores are gone?
Protein.
What are the products of anaerobic respiration in plants?
Ethanol and carbon dioxide.
What is anaerobic respiration called in plants?
Fermentation.
What type of conditions will anaerobic respiration occur in plants?
In the roots of boggy or water logged soil.
What is a microbe?
Tiny organisms that we cannot see with the naked eye
Name the microbe that can carry out anaerobic and aerobic respiration.
Escherichia coli or yeast
What type of respiration occurs in bacteria far below the ocean’s surface?
Anaerobic
In the experiment described, why is sugar added to the yeast?
To provide glucose for respiration.
In the experiment described, why does the balloon inflate?
As carbon dioxide gas is produced.
What is the useful product of fermentation for brewing?
Ethanol
What is the useful product of fermentation for baking?
Carbon dioxide
What is ‘gasohol’?
a fuel containing a mixture of gasoline and alcohol
In the experiment described, why was sugar added to the yeast?
So the yeast could carry out respiration.
In the experiment described, what was the independent variable?
Temperature
In the experiment described, what was the dependent variable?
Number of bubbles of carbon dioxide
In the experiment described, identify 2 possible control variables.
Volume of yeast, volume of glucose, time counting bubbles.
What does the term repeatable mean?
Repeating the experiment gives two or more sets of measurements that are similar
What is the purpose of respiration?
To release energy in a form that animals can use.
What is the common reactant between aerobic and anaerobic respiration?
Glucose
Which form of respiration is more efficient?
Aerobic respiration.
What type of respiration occurs when you are sprinting?
Anaerobic respiration.
Where does aerobic respiration occur in a cell?
Mitochondria
Where does anaerobic respiration occur in a cell?
Cytoplasm
What is an enzyme?
A biological catalyst
What does an enzyme do?
Increases the rate of a reaction/ helps to break up glucose molecules.
What two reactants do plants need to produce glucose?
Carbon dioxide and water
What are the products of photosynthesis?
Oxygen and glucose (and energy)
When does photosynthesis occur?
During the daytime
What does the plant use glucose for?
New growth and respiration.
What is the name of the storage molecule of glucose?
Starch
What chemical is used to test for starch?
Iodine
Why is a leaf boiled in ethanol when testing for starch?
Kills the cells and removes chlorophyll
Why are leaves green?
They contain chlorophyll (a green pigment)
What is the name of the pigment found in leaves?
Chlorophyll
Where does photosynthesis happen in a leaf cell?
Chloroplasts
Which layer in the leaf is waterproof?
Waxy cuticle
Why are upper epidermis cells transparent?
To allow light to pass through to the palisade cells
Which layers in the leaf contain chloroplasts?
Palisade mesophyll and spongy mesophyll
Why does the spongy mesophyll have air pockets?
To allow gases to move through the leaf
What is the function of the stomata?
To control materials to flow in and out of the leaf
Which cells control the opening and closing of the stomata?
Guard cells
How do water and minerals enter the plant?
Through their roots
What happens to cells if they do not have enough water?
They become flaccid
Define the term transpiration.
The loss of water from a plant.
Which part of the plant is water lost from?
Stomata
What is the function of xylem cells?
They carry water and minerals
What is the function of phloem cells?
They carry dissolved sugars
Why do root hair cells have a large surface area?
To penetrate between soil particles.
What is the function of the guard cells?
To open or close the stomata
Define the term deficiency.
A lack or shortage of something.
Describe a plant with a nitrate deficiency.
Poor growth and yellow leaves
What is the function of magnesium?
To produce chlorophyll.
What does the plant add to glucose to produce protein?
Nitrogen.
What is a ‘macroelement’?
Minerals that plants use in large quantities.
What can a farmer add to a field to replenish nutrients?
Fertilisers
What elements are found in an NPK fertiliser?
Nitrogen, phosphorus and potassium
Why is manure a better fertiliser than commercial fertilisers?
It is natural and longer lasting
Why is glucose needed by a plant?
For growth and to increase biomass
Which grows faster- a tundra moss or a tropical rainforest tree?
Tropical rainforest tree
What is a limiting factor?
Something that limits the rate of photosynthesis
Name the 3 limiting factors for photosynthesis.
Light intensity, carbon dioxide concentration and temperature.
Why does increasing the concentration of carbon dioxide increase the rate of photosynthesis?
Carbon dioxide is a reactant of photosynthesis.
Why does increasing light intensity increase the rate of photosynthesis?
Light is required for photosynthesis.
What is an enzyme?
A biological catalyst
What happens to the enzyme if temperature gets too high?
It denatures.
What 3 factors affect the rate of photosynthesis?
Temperature, light intensity and carbon dioxide concentration.
How can you measure the rate of photosynthesis in pondweed?
Count the bubbles given off
What is the independent variable in the experiment?
Light intensity (distance from light source)
What is the dependent variable in the experiment?
Number of bubbles produced.
Name 2 possible control variables for the experiment.
Species of pond weed, acclimatisation time, time counting bubbles, temperature, colour of light.
What is the function of sodium hydrogen carbonate?
Adds carbon dioxide to the water.
Why is the pond weed left for 5 minutes before you count the bubbles?
To allow the plant to acclimatise (start photosynthesising)
Why is an experiment repeated 3 times?
To calculate a mean.
Why is it important to analyse data from an experiment?
To see if there are patterns in the data
Which variable is drawn on the x-axis?
Independent
Which variable is drawn on the y-axis?
Dependent
How much of the page should a graph take up?
At least half a page
How should points be plotted on the graph.
A small x
What is considered in an evaluation?
Good and bad points, reliability, repeatability
Define the term repeatable.
Repeating the experiment gives similar results.
What will be drawn on the graph to show the trend in the data?
A line of best fit.
