Chapter 6
Functions of leaves
Simple leaf
Do not divide into smaller leaflets, instead stay central to the stem.
Compound leaf
Steps of leaf development
Monocot leaves
Eudicot leaves
Veins in the leaf are usually parallel
Vascular bunches are arranged in a complex manner.
Only have one cotyledon in seed formation.
Instead of a taproot, a fibrous root system is present.
Both types of leaves have major differences in the plant they reside in als
Vascular bundles are arranged in a ring.
Host plant usually uses a taproot instead of fibrous roots.
The veins are usually netlike in the leaf.
Flowers are arranged in multiples of 4-5.
Eudicots have two cotyledons during seed stage.
Flowers are arranged in a multiple of three, usually
Transpiration - Leaves aid in letting the plant release or gain water from the atmosphere. .
Respiration - Leaves also help plants exchange gases with the atmosphere.
Photosynthesis - leaves produce energy for the whole plant through photosynthesis.
Food storage and production - Leaves also help store starches or sugars produced by the plant for later use.
Compound leaves can branch off into smaller leaflets,
- Senesence - Physical and chemical changes occur leading to the death of the plant. Yellowing of leaves is a sign of senescence.
- Ripening stage. Plants now produces seeds of their kind, in the form of nuts or fruit.
- Reproductive stage - Occurs after the vegetative stage. Plants are now capable of producing seeds.
- Vegetative stage - The plant is growing in all forms, roots, leaves, and stalk/trunk as well.
The netlike aspect of the veins assists in transport to every cell of the leaf.
The netlike aspect of the veins in the leaf are comparable to the capillaries of the human body.
The ring structure is similar to the root structure.
The ring structure allows for the efficient transportation of nutrients and water throughout the tissues.
This is one of the defining characteristics of eudicots and can be a useful indicator of which type of plant is in question.
The complexity of the vascular branches ensures the delivery of cargo to and fro the leaf.
Monocot and eudicot leaves do share the complexity of their vascular systems in common, as the need to transport is no less in either.
Simple leaves
Without photosynthesis, 99% of plants would be nonexistent.
is a major component in the synthesis of atp in plants
a light dependent reaction using the eternal energy of the sun.
Transpiration can help plants gain water, as well as lose it.
Without transpiration,the cohesion-tension theory would not be possible.
A fibrous root system is highly effective in obtaining water, similar to the complexity of the vascular complexity of a leaf.
In comparison to a Eudicot, a monocot only has 3 leaves.
a taproot is effective in drier conditions, as it penetrates deeply into the soil to find hard earned water.
a taproot goes much deeper than a fibrous root system .
Respiration allows for the carbon dioxide present in the atmosphere to enter the plant and be converted to oxygen.
Although respiration is prevalent in every plant, the rate of plant respiration is not keeping up with the amount of carbon dioxide being produced.
This leads to global warming.