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
Give 2 examples of limiting factors that may not allow the rate of photosynthesis to increase as the % of carbon dioxide increases
Any 2 from water, light and temperature
The graph showing the impact that the % level of carbon dioxide has on photosynthesis is also the same for _____
water
When plants are very cold, everything acts very quickly/slowly
slowly
As the temperature slowly increases, the rate of photosynthesis…
slowly increases to a point, until it gets too hot and the enzymes start to denature
What happens to the rate of photosynthesis when the enzymes are at the optimum temperature?
There is lots of photosynthesis going on
What happens during photosynthesis when enzymes get warmer than the optimum temperature/it starts to get too hot for the enzymes?
They begin to denature and the rate of photosynthesis will fall very rapidly
True/False: Enzymes die when they are too hot
False, they become denatured. They are not killed
True/False: Night time is the best time for photosynthesis to occur
False, when it is dark not much photosynthesis occurs
As we get further through the day and light intensity increases, the rate of photosynthesis…
increases to a point where it is no longer the limiting factor and other things like the reactants or temperature need to be increased
True/False: Photosynthesis stops occuring when the blue line is flat
False, the rate of photosynthesis is just not increasing as much as it was before. It is at a steady rate
True/False: The rate of photosynthesis depends on lots of different things all at once
True
The glucose from photosynthesis is stored as ______
starch
The most obvious example of starch is…
potatoes
What happens in the palisde mesophyll?
Photosynthesis
What is the cuticle of a cross section of a leaf?
Waxy layer
What do the upper and lower epidermis of a leaf do?
Cover the plant
What is spongy mesophyll in a leaf?
A space for gas exchnge
What takes place in the guard cell and stomata of the cross section of a leaf?
Transpiration
Inside a plant there is p_____ and x____
phloem and xylem
What does the xylem carry?
Water
In what direction do the xylem generally carry water?
Upwards
Where do the xylem transfer water from and to?
From the roots where it is collected to the leaves where it can be used for photosynthesis
Why do the xylem carry water to the leaves?
So it can be used for photosynthesis
What do the phloem carry?
Ions and food
In what direction to the phloem generally carry ions and food?
Downwards
Where do the phloem carry food and ions from/to?
From the leaf where food can be made in photosynthesis to the roots where it can be stored in, for example, potatoes
Why do the phloem transfer food and ions from the leaves to the roots?
Food is made in photosynthesis and then it travels to the roots where it can be stored in, for example, potatoes
There are little/several factors that affect the rate of transpiration
several
Transpiration not only involes water moving ___ of the stomata but also up through the _____
out, xylem
True/False: Bright light leads to less transpiration
False, it leads to more transpiration
More light means more/less photosynthesis, which means there is going to need to be more/less water brought up into the cell
more, more
True/False: A high temperature will lead to more transpiration
True
Why will a high temperature lead to more transpiration?
The rate of reaction will happen faster
True/False: High wind will lead to less transpiration
False, it will lead to more
Why does high wind lead to more transpiration?
It brushes against the leaf and moves things out the way so diffusion will play a part
High humidity leads to higher/lower transpiration
lower
Why does high humidity lead to lower transpiration?
Water will struggle to leave the leaf because there is a very high concentration of water - it is very humid outside
Photosynthesis is where…
energy enters most of the food chains on Earth
Organisms that carry out ______________ have crucial positions at the start of food chains
photosynthesis
Plants are able to make their own food by what process?
Photo synthesis
During photosynthesis, what use energy from the sun to make glucose?
Photosynthetic organisms such as green plants and algae
Give an example of a photosynthetic organism
Any from green plants and algae, etc
During photosynthesis, photosynthetic organisms use what from the sun to make what?
energy to make glucose
Some of the glucose produced as a result of photosynthesis is used to make larger, complex molecules that…
the plants or algae need to grow
What make up an organism’s biomass?
The larger, complex molecules that some of the glucose from photosynthesis is used to make - plants or algae need this to grow
Biomass
The mass of living material
How does energy stored in an organisms’ biomass work its way through the food chain?
As animals eat them and each other
True/False: Photosynthetic organisms are the main producers of food for nearly all life on Earth
True
Where does photosynthesis happen?
Inside chloroplasts
Why does photosynthesis happen inside chloroplasts?
They contain chlorophyll, which absorbs light
Chlorophyll absorbs _____
light
How is energy transferred to the chloroplasts?
By light
What is the balanced chemical equation for photosynthesis?
6CO2 + 6H2O -> C6H12O6 + 6O2
Photosyntesis is an exo/endothermic reaction
endothermic
What does photosynthesis being an endothermic reactoin mean?
Energy is taken in during the reaction
Give 2 factors that affect the rate of photosynthesis
Any 2 from light intensity, the concentration of CO2 and the temperature
Which factors that affect the rate of photosynthesis can become a limiting factor?
All of them
If temperature is the limiting factor of rate of photosynthesis… what does this mean?
It’s stopping photosynthesis from happening any faster
The temperature has to be ____ _____ for photosynthesis?
Just right
Why does temperature affect the rate of photosynthesis?
It affects the enzymes involved
Usually, if the temperature is the limiting factor of photosynthesis it’s because it’s too high/low
low
The enzymes needed for photosynthesis work more quickly/slowly at low temperatures
slowly
If a plant gets too hot, the enzymes needed for photosynthesis and its other reactions will…
be denatured
At which temperature will a plant get too hot and the enzymes it needs fo rphotosynthesis denature?
About 45 degrees celcius, which is pretty hot for outdoors although greenhouses can get that hot if you’re not careful
True/False: The temperature outside is often over 45 degrees celcius
False, although greenhouses can get that hot if you’re not careful
Not enough light speeds up/slows down the rate of photosynthesis
slows down
Light transfers the ______ needed for photosynthesis
energy
At first, as the light level is raised, the rate of photosynthesis…
increases steadily - the rate of photosynthesis is directly proportional to light intensity
True/False: The rate of photosynthesis is directly proportional to light intensity
True, but only up to a certain point
Why will light intensity not make a difference after a certain point?
It’ll either be the temperature or the CO2 level which is the limiting factor
How can you investigate light intensity in a lab?
By moving a lamp closer to or further away from a plant
If you just plot the rate of photosynthesis against “distance of lamp from the plant”, what shape graph will you get?
You get a weird-shaped graph
To get an accurate graph showing how light intensity affects rate of photosynthesis, you need to measure the light intensity at the plant using…
a light meter
The square of the distance from the lamp and the light intensity are inversely proportional to each other. this means…
as the distance increases, the light intensity decreases
The light intensity decreases in proportion to the ______ of the distance
square
The square of the distance from the lamp and light intensity being inversely proportional is called the…
inverse square law
Light intensity ∝ 1 / d2 is the equation for…
the inverse square law
The inverse square law means that if you halve the distance, the light intensity will…
Be four times greater / double
The inverse square law means that if you double the distance, the light intensity will…
Halve/be fall times smaller
You can use 1/d2 as a measure of…
light intensity
Too little carbon dioxide speeds up/slows down photosynthesis
slows down
CO2 is one of the ___ materials needed for photosynthesis
raw
As with light intensity, increasing the CO2 concentration does what to the rate of photosynthesis?
Increases it up to a point
After a point, a graph showing how CO2 concentration affects the rate of photosynthesis will…
flatten out
What does the graph showing how increasing CO2 concentration affects the rate of photosynthesis flattening out show?
That the CO2 is no longer the limiting factor
In terms of the rate of photosynthesis, as long as CO2 is in plentiful supply then…
light or temperature is the factor limiting photosynthesis
Canadian pondweed can be used to measure the effect of what on the rate of photosynthesis?
Light intensity
When investigating the rate of photosynthesis, the rate at which the pondweed produces oxygen corresponds to the rate at which…
it’s photosynthesising
The faster the rate of oxygen production, the faster/slower the rate of photosynthesis
Faster
When investigating how changing light intensity affects the rate of photosynthesis, the gas syringe should be full/empty to start with
empty
Sodium hydrogencarbonate may be added to the water to…
make sur ethe plant has enough carbon dioxide
Why would sodium hydrocarbonate be added to water to make sure the plant has enough carbon dioxide?
Soidum hydrocarbonate releases CO2 in the solution
A source of _____ _____ is placed at a specific distance from the pondweed
white light
The pondweed is left to _______________ for a set amount of time
photosynthesise
True/False: This experiment can be modified to test the effect of temperature of carbon dioxide concentration
True
What is important to remember when considering modifying this experiment to test the effect of temperature or carbon dioxide concentration?
To only change one variable at a time
True/False: You must use Canadian pondweed when measuring the effect of light intensity on the rate of photosynthesis
False, you can also use algal balls instead of pondweed. These are little balls of jelly which contain algae
What is another way of measuring how much oxygen is produced in this experiment?
By counting the number of bubbles given off in a certain time - but this is less accurate
What would be the drawback of counting the number of bubbles given off in a certain time to measure how much oxygen is produced?
It would be less accurate
After is photosynthesises, the oxygen released will collect in the…
gas syringe
The oxygen collecting in the gas syringe allows you to…
accurately measure the volume of oxygen produced
When this experiment is finished, it is repeated with…
the light source at different distances from the pondweed
How can the rate of oxygen production at each distance be calculated?
Volume produced / time taken
For this experiment, any variables that could affect the results should be…
controlled
How would you control the temperature in this experiment?
By putting the conical flask in a water bath
How would you control the carbon dioxide concentration in this experiment?
By adding a set amount of sodium hydrogencarbonate to a set volume of water
You can compare the rate of photosynthesis at different light intensities by comparing the…
rate of oxygen production
Increasing light intensity increases/decreases the rate of oxygen production
increases, but only until temperatore or CO2 become the limiting factor instead
Flowering plants have how many types of transport vessel?
Two
What are the two types of transport vessels in flowering plants?
Xylem and phloem
True/False: Both xylem and phloem go to every part of the plant
True
What do root hairs take in?
Minerals and water
Tje cells on the surface of plant roots grow into “_____”
hairs
Where do the cells on the surface of plant roots which grow into “hairs” stick out?
Into the soil
Each branch of a root will be covered in millions of microscopic _____
hairs
What do the microscopic hairs on branches of a root give the plant?
A large surface area
How is a plant having a large surface area beneficial?
For absorbing water and mineral ions from the soil
The concentration of mineral ions is usually higher/lower in the root hair cells than in the soil around them
higher
By what process are mineral ions absorbed in root hair cells?
Active transport
Why are mineral ions absorbed from soil to root hair cells by active transport?
The concentration of mineral ions is usually higher in the root hair cells than the souil around them
By what process to root hair cells absort water?
Osmosis
Phloem tubes transport
Food
Phloem tubes are made of columns of…
elongated living cells with small pores in the end walls
What do the columns of elongated living cells with small pores in the end walls of phleom tubes do?
Allow stuff to flow through
What do phloem tubes do?
Transport food substances made in the leaves to the rest of the plant for immediate use
Phloem tubes transport food substances (mainly _______)
sucrose
