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KS3 plants
Question | Answer |
---|---|
State the limiting factors which affects the rates of photosynthesis | temperature, light and carbon dioxide |
Name the organ through which plants absorb water | roots |
Name the tissue through which water can flow through plants | xylem |
Name the tissue through which sugar solution can flow through plants | phloem |
Name the reactants needed for respiration | oxygen and sugar |
State where photosynthesis takes place in plants | leaves |
Name chemicals containing minerals to enhance plant growth | fertilisers |
Name specialized cells with containing lots of chloroplasts | palissade cells |
Write the word equation for photosynthesis | carbon dioxide + water –-(sunlight)--> sugar + oxygen |
State the function of chlorophyll | absorbs sunlight |
Name the type of plant which converts the suns energy into food | green plant |
Name the cells through which water is absorbed | root hair cells |
Name the store of energy/food found in cells | starch |
Explain why palisade cells are found at top of leaves | Because this is where there is most sunlight, so by having it at the top of leaves, it maximises the amount of sunlight absorbed |
Name the process by which plants turn the Sun’s energy into food | photosynthesis |
Name the products of respiration | Carbon Dioxide and Water |
Describe the chemical used to test for starch | Iodine; if there is starch, the food will go blue-black; if there is no starch it will stay brown |
Name cells through which gases can diffuse in an out of leaves | spongy cells |
Give two adaptations of root hair cells | Thin cell wall and a long extension of the cell |
Explain why root hair cells have a long extension | Provides a large surface area (1); to collect more water(1) |
Explain why root hair cells have a thin cell wall | So that it is easier for water to go through |
Would you expect the stomata to be close or open on a hot sunny day? Explain your answer | Close to prevent too much water vapour from escaping |
Why is the cuticle make of a waxy layer? What is the job of the wax? | To prevent water from escaping |
State what organelle (part of the cell) would you expect to find in great numbers in the palisade cells? | Chloroplasts |
Explain why would you expect the spongy cells to contain only a few chloroplast? | There is little direct sunlight that reaches the bottom of leaves where chloroplasts are found; so less need to absorb sunlight |
Explain why are the palisade cells so tightly packed together? | To maximise the amount of sunlight that can be absorbed |
Explain why are the spongy cells so loose? | To allow air flow more easily |
State the mechanism/process by which the gases move from the air space into the spongy cells | Diffusion |
Explain how diffusion works | The gases go from an area of low concentration to an area of high concentration |
What is the function of the waxy cuticle? | to prevent water loss |
What is the function of the palisade cells? | they are the cells responsible for photosynthesis. There are lots of chloroplast in a palisade cell. |
What is the function of the stomata? | It is the hole through which the gas enter |
What is the function of the guard cells? | they are the cell around the stomata. They will close up or open the stomata to let gases in and out. |
How are spongy cells adapted for gas exchange? | They are loosely-packed with unusually large intercellular air spaces where gases can collect and mix. |
What is the function of the Cell wall? | support the plant |
What is the function of the Cell membrane? | controls what goes in and out of a cell |
What is the function of the Nucleus? | controls cell’s activities |
What is the function of the Chloroplast? | absorbs sunlight; where photosynthesis takes place |
What is the function of the Cytoplasm? | where chemical reactions take place |
What is the function of the Vacuole? | Store water and waste |
What is the function of the Starch grain | how food is stored in a plant cell |
What is the function of the Mitochondrion | Produces the energy a cell needs to carry out its functions |
Do you expect leaves with a larger surface area (broad leaves) to lose more or less water? | They will lose more water as there are probably more stomata |
In a hot climate, would you expect to find more or fewer stomata on large leaves? | There are probably less stomata PER CM2, so that there is LESS water loss |
What other advantages are there for a leaf to have a large surface area? | Can capture MORE light to produce MORE sugar |
Explain why houseplants have more shiny leaves than outdoor plants? | In a house, it is hot, so to minimise water loss, the plant will have a thicker cuticle |
What is the name of the green pigment found in chloroplast; this pigments absorbs light | Chlorophyll |
Give two uses of sugar by a plant? | For respiration; to store as starch |
Compare the amount of photosynthesis and respiration during the night | At night, the plant respires but does not photosynthesise (no light) |
Compare the amount of photosynthesis and respiration during the day | During the day, the plant does more photosynthesis than respiration; but respiration still takes place |
What is the relationship between starch and sugar? | Starch is a polymer of sugar (many sugar molecules stringed up together make a starch molecule) |
Explain the advantage for plants in the shade to have leaves with a large surface area? | to absorb more light |
State which organelles are found ONLY in plant cells? | Chloroplast, vacuole and cell wall |
State which organelles are found BOTH in plants and in animal cells? | Cell membrane, cytoplasm and nucleus |
Explain how a palisade cell is adapted to do its job by comparing to a normal cell | A palisade cell has MORE chloroplast than a normal plant cell (1) so it can collect MORE ligh (1) |
State 3 things that the plants needs to do photosynthesis | carbon dioxide, water and light |
Describe how lots of sugar molecules are transformed into a molecule of starch | the molecules of sugar join together |
Why does the plant need starch? | starch is a store of energy so that the plant can use it later |
Why is there no starch in a plant that was left for 2 days in the dark? | During those 2 days, the plant did not do photosynthesis, so did not make "food". The plant had to use up its store of energy= the plant had to use up the starch |
Pourquoi les plantes ont besoin de lumière ? | - Pour grandir une plante a besoin de lumière. - La plante a besoin d'eau et de soleil pour pousser. - Les plantes se penchent vers la lumière lorsqu'elles poussent. - Il n'est pas possible de faire pousser une plante dans l'obscurité. |
Quel est le rôle de la lumière dans la photosynthèse ? | La photosynthèse nécessite de la lumière, de l'eau et du gaz carbonique. Une partie du spectre de la lumière est absorbée par les feuilles des plantes. |
Quel est le rôle de la feuille ? | alimentation et respiration. Grace à la chlorophylle contenue dans les cellules de son limbe, elle transforme, sous l'action solaire, le gaz carbonique de l'air et hydrogène de l'eau en glucides, avec dégagement d'oxygène, c'est la photosynthèse. |
pourquoi une plante jaunit ? | Substrat trop humide. Un excès d'arrosage est une cause fréquente de jaunissement, notamment pour les plantes en pot. cela induit le pourrissement des racines, ce qui est irrémédiable : la plante ne peut plus se nourrir correctement. |
Peut-on dire que les plantes respirent la nuit et Font de la photosynthese le jour? | Non, La nuit, la plante ne realise plus de photosynthese et n'absorbe donc pluse de CO2. Mais elles une production de CO2 et une absorption d'O2 (respiration); mais le jour les cellules ont besoin de respire aussi |
Sans lumiere, que devient une plante | Une plante privee de lumiere va s'allonger et devenir tres pale, mais faute de pouvoir faire la photosynthese et donc d’avoir de l'energie, elle finira par morir. |
Dans quelle organelle se trouve la chlorophylle? | Ca se situe dans les chloroplastes des cellules vegetales |
Est-ce qu’une plante a besoin de la terre? | non, une plante n'a pas besoin de terre pour vivre. |
Est-ce qu’un cactus a des feuilles? | oui, un cactus a des feuilles mais les feuilles se sont refermées pour qu’ils ne perdent pas beaucoup d’eau. |
Par où le dioxyde de carbone entre-t-il dans une plante? | les dioxyde de carbone entre en dessous de la feuille par les stomates. |
Est-ce que les feuilles à plusieurs couleurs on du chlorophylle? | ou, les feuilles à plusieurs couleur on du chlorophylle |
A quoi sert la chlorophylle dans une plante? | dans une plante, la chlorophylle sert à donner la couleur verte pour qu elle puisse capturer la lumière, et utilisé pour la photosynthèse. |
Est-ce que les plantes peuvent vivre dans l'eau? | oui, il y a plusieurs plantes vivant dans l'eau. |