Photosynthesis
Chlorophyll & chloroplasts
Gas exchange
Limiting factors
Water & Minerals
100
What are the reactants in photosynthesis?
Carbon dioxide & water
100
Where is chlorophyll found in plants?
Chloroplasts
100
What cells allow gas exchange to happen in the leaf?
Stomata & guard cells
100
What are some factors that affect the rate of photosynthesis?
Water, light, carbon dioxide concentration, mineral availability, temperature
100
Other than being a reactant of photosynthesis, why do plants need water?
Keeps cells firm to support the stems and leaves
200
What are the products in photosynthesis?
Glucose & oxygen
200
Which plant structures contain the most chloroplasts? Why?
Leaves bc that’s where most of the sunlight is
200
What’s the function of the cuticle?
Protects against water loss, stops gas exchange from happening everywhere
200
How can you measure the rate of photosynthesis?
Water plants – release oxygen just like land plants but bc they’re underwater you can see the gas bubbles
200
What are some adaptations of plants that allow them to survive in places with little water?
Deep or wide spreading roots, thick protective outer layers to prevent water loss, store water in their tissues
300
Why do plants need to photosynthesize?
To make food
300
Is photosynthesis exothermic or endothermic? Why?
Endothermic bc consumes more energy that it produces
300
What’s the difference between xylem and phloem?
Xylem = water & other nutrients
Phloem = food & other organic materials
300
Describe the graph that explains how temperature affects the rate of photosynthesis
300
What happens when a plant gets too much water?
Roots die and rot => whole plant dies
400
Why do humans need plants?
Food, clothes, building materials, oxygen, air filtration, paper, medicine, etc etc etc
400
Name some other substances chloroplasts contain
ll the enzymes needed to join carbon dioxide and water together to make oxygen
400
Why is gas exchange important in the leaf?
Need to allow CO2 to enter the leaf for photosynthesis and waste (oxygen) to leave
400
How can you increase the rate of photosynthesis?
greenhouses (more light, warmer (if not too warm))
400
What are the essential minerals plants need?
NPK – nitrogen, phosphorous, potassium
500
Some people claim that talking to houseplants makes them grow better. What’s a possible scientific explanation for why this might be true?
We exhale carbon dioxide which plants use to photosynthesize
*remember, CO2 is almost always the limiting factor!!
500
Why is chlorophyll green?
Many potential reasons – but basically bc evolution decided that green worked the best for absorbing sunlight
500
In what ways are leaves well adapted for photosynthesis?
- Air spaces in spongy layer allow gases to diffuse easily
- Often large and flat to incr surface area of sunlight absorption
500
Which would have the fastest rate of photosynthesis:
Middle of a sunny day in July
Cloudy day in August
Early morning in late September
Middle of a sunny day in July – nice and hot, lots of light
Cloudy day: light = limiting factor
Late September: temperature = limiting factor
500
Why do farmers use fertilizers?
Give plants minerals that have been leeched out by over-farming the soil
Makes plants grow as well as possible