The Leaf
Why do plants have leaves?
To make food for the plant
Which pigment is most responsible for absorbing the sun’s radiation during photosynthesis?
Chlorophyll
State the word formula for photosynthesis
Carbon dioxide + Water ( + Energy from Light) = Glucose + Oxygen
What is the term for the type of tree that loses its leaves in the winter?
Deciduous
The process of using the sun’s energy to produce food is….
Photosynthesis
Why do leaves look green?
Leaves reflect green light, but absorb red and blue light.
Identify these pigments by their color
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1. Chlorophyll
2. Anthocyanins
3. Carotenoids
In which small organelles does photosynthesis take place inside plant cells?
Chloroplasts
What is the term for the process of a leaf falling from a tree?
Abscission
What tissue carries sugar from leaves to all of the cells in the plant?
Phloem
What tissue carries water from the roots to the leaves?
Xylem
Which pigment has the smallest molecules? Explain your answer.
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Pigment 3 has the smallest sized molecule. Small molecules will move the farthest on a chromatography strip as it is easier for small molecules to move through the paper.
Plants are made of trillions of atoms, mostly of hydrogen, carbon and oxygen. What is the original source for most of these atoms that make up plants?
Carbon Dioxide from the atmosphere
Water
What is photoperiod and how are plants affected by it?
Photoperiod is the time of sunlight each day. The shortening photoperiod in the fall is an important trigger for the abscission process for leaves.
Explain Why do leaves change their color in the autumn?
Deciduous trees lose their leaves in the autumn by restricting the flow of water into the leaves. This causes the chlorophyll to break down and disappear. This reveals other colorful pigments that are in the leaves such as carotenoids and anthocyanins.
What 3 gases pass through the stomata of leaves?
Carbon Dioxide
Oxygen
Water Vapor
What type of pigment does this plant have? Why would a plant have an unusual pigment like this?
The red pigment in this plant is anthocyanin. A plant may have this pigment if it lives on the forest floor where it receives only green wavelengths of light. The pigment allows the leaves to absorb wavelengths of light for photosynthesis that regular plants cannot use.
Outline the process of transpiration.
Why is it necessary?
How is it wasteful?
Transpiration is evaporation of water from the leaves of plants.
The water exits the leaves via the stomata
When water evaporates in leaves, more water is pulled up from the roots.
Plants need water to create glucose
Transpiration can be wasteful because most of the water is lost into the air and is not used for photosynthesis
Evergreens are any tree or shrub that usually have needle-shaped or scale-like leaves. There are more than 550 species of evergreens. What is the more scientific term for "Evergreen" ?
Conifer or Coniferous
How have deciduous trees adapted to winter?
How have evergreen trees adapted to winter?
Deciduous trees adapt to winter by losing their leaves, then growing new leaves in the spring.
Evergreen trees have adapted to winter by developing a thick waxy cuticle on their leaves, and by keeping chemicals in the leaves that resist freezing.
Coming from a greek word meaning, heavy-duty fence that's strong enough to keep out intruders. This area found towards the top side of a leaf consists of tightly packed "columns" of cells.
Palisade Mesophyll
What is an accessory pigment? Other than leaves, identify one example of how plants use accessory pigments.
An accessory pigment are pigments other than chlorophyll. These pigments can absorb different wavelengths of light and pass that energy to chlorophyll. Plants use accessory pigments to brightly color flowers and fruit.
According to the action spectrum for chlorophyll, which wavelengths (2) of light cause the fastest rate of photosynthesis?
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430 nm and 670 nm
Glucose is a simple sugar. When many glucose molecules are put together it creates a complex sugar known as what? This complex sugar makes up the woody parts and cell walls of plants.
Cellulose
Why do trees look like this? How is the characteristic useful?
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Trees become dormant (slow down) during the winter. This creates a brown ring each year. By counting the dark rings, it can be determined how many winters the tree has survived.