Topic Six Flashcards
Plant Structures and thier functions
In a food chain, consumers eat other organisms. What word is used to describe organisms that make their own food?
producers
What process do plants and algae use to make their own food?
photosynthesis
In what sub-cellular part of a plant cell does photosynthesis occur?
chloroplast
What substance from the air do plants need for photosynthesis?
carbon dioxide
What substance from the ground do plants need for photosynthesis?
water
What organs do plants use to get water from the ground?
roots
How are roots adapted to getting water from the ground quickly?
large surface area, root hair cells
What energy-storing compound is made in photosynthesis?
glucose
Suggest one use for glucose in a plant.
respiration, making other substances
In what sub-cellular part of a plant cell does respiration occur?
mitochondria
What product of photosynthesis is a gas at room temperature?
oxygen
Plants photosynthesise. Name one other group of organisms that photosynthesise.
algae or cyanobacteria
What reactant in photosynthesis is a gas at room temperature?
carbon dioxide
What are all the materials that make up an organism known as?
biomass
In what subcellular parts of plants does photosynthesis occur?
chloroplasts
Where does all the energy originally come from in most food chains?
the Sun
What polymer inside chloroplasts is made from glucose?
starch
Name the main sugar that is transported around most plants.
sucrose
What do we mean by the ‘rate’ of photosynthesis?
the speed of the reactions
What is a rate of reaction?
how fast a reaction happens
What do we call something that prevents a rate of reaction increasing?
limiting factor
If light intensity is a limiting factor, what happens to the rate of photosynthesis when it is increased?
The rate increases.
When there is plenty of light and plenty of carbon dioxide, suggest one factor that could be limiting.
temperature or water
What happens to the rate of photosynthesis as a plant is moved further away from a light source?
It decreases.
What relationship is shown by a straight line through the points on a scatter graph?
linear relationship
What sort of linear relationship is shown by a straight line through the origin?
direct proportion
Higher and Triple only- By what law does light intensity vary with distance?
inverse square law
Higher and Triple only- What is light intensity inversely proportional to?
distance squared
What happens to plants if they do not get enough water to fill their cells?
They wilt.
What term is used to describe the amount of a substance in a certain unit volume?
concentration
What term is used to describe the overall movement of particles from higher concentration to lower concentration?
diffusion
What term is used to describe the overall movement of solvent particles from higher concentration to lower concentration through a partially permeable membrane?
osmosis
What is the gradual change in concentration from one place to another called?
concentration gradient
What process do cells use to transport substances against their concentration gradient?
active transport
What adaptation do some root cells have in order to increase the amount of water they can absorb?
root hairs
Why do cells that use active transport often have a lot of mitochondria?
Active transport needs a lot of energy.
What do plants need nitrate ions for?
making proteins
Through what vessels is water moved up a plant?
xylem vessels
Through what tissue are sugars transported around a plant?
phloem tissue
What is the flow of water through a plant called?
transpiration
In what vessels does water flow?
xylem vessels
In what vessels are dissolved mineral ions carried?
xylem vessels
Give one other function of xylem vessels.
supporting the plant
What tissue is used for translocation?
phloem
Give the names of the two most common cells in phloem tissue.
sieve tubes and companion cells
Why do companion cells contain many mitochondria?
because they actively pump sucrose in and out of sieve tubes
If the humidity of the air around a plant is reduced, what happens to the rate of transpiration?
it increases
Which cells create the air spaces inside a leaf?
spongy cells
What term describes trees that lose their leaves in winter?
deciduous
Give one function of cuticle.
to prevent microorganisms entering/to prevent water entering/to reduce evaporation of water
What cells control the opening and closing of stomata?
guard cells
Explain why conifer trees have their stomata in pits.
to trap water vapour and reduce water loss
What word describes trees that lose their leaves in winter?
deciduous
Why do deciduous trees lose their leaves in winter?
to prevent water loss when water in the ground may not be available because it is frozen
Why is it an advantage for a plant root to grow downwards?
to anchor the plant/to reach water
Why is it an advantage for a plant shoot to grow towards the light?
to get energy for photosynthesis
What is a growth in response to a stimulus called?
tropism
What is a growth in response to the stimulus of light called?
photosynthesis
What is a growth away from light called?
negative phototropism
Name a part of a plant that shows negative phototropism.
root
What effect do auxins have on cells in a plant shoot?
cause them to elongate
What effect do auxins have on cells in a plant root?
stop them elongating
Name the growth response of a root in the direction of gravity.
positive gravitropism
Name the group of plant hormones that are used to help seeds germinate.
gibberellins
Name the plant hormone that is a gas and is used to ripen fruit.
ethene
What is the word equation for photosynthesis?
Water + carbon dioxide -> oxygen + glucose
Why is light not put in the word equation for photosynthesis?
It is not a reactant - it is just a condition that’s needed
What is the symbol for water?
H20
What is the symbol for carbon dioxide?
CO2
What is the symbol for oxygen?
O2
What is the symbol for glucose?
C6H12O6
What is the balanced equation for photosynthesis?
6H2O + 6CO2 -> 6O2 + C6H12O6
Which of the following is the correct way to write the symbol for carbon dioxide?
CO2
What happens during photosynthesis?
Energy is taken from light and locked up in glucose
Is photosynthesis and exothermic or an endothermic reaction?
Endothermic
What does photosynthesis being an endothermic reaction mean?
It takes in energy
Name 2 requirements for photosynthesis
Any 2 from chlorophyll, water, carbon dioxide and sunlight
What is chlorophyll?
The green pigmentin leaves
Why are water and carbon dioxide needed for photosynthesis?
They are the reactants
The levels of chlorophyll, water, carbon dioxide and sunlight have a minor/major impact on how much photosynthesis takes place
major
True/False: The rate of photosynthesis depends on the % level of carbon dioxide
True
As the % level of carbon dioxide increases, the rate of photosynthesis…
increases to a point until there are other limiting factors
Why does the % level of carbon dioxide only cause the rate of photosynthesis to increase to a point?
There are other limiting factors such as water, light and temperature