7th Grade Homework
Due: Friday, February 21 / Name ______
Date ______
TURGOR PRESSURE:
Controlling Turgor Pressure
An important function of cell wall is to maintain turgor pressure. Turgor pressure or turgidity is defined as the pressure applied by the contents of the cell on the cell wall. It is determined by the amount of water present in the one of the plant cell organelles, the vacuoles. This force that is exerted gives the plant rigidity and helps to keep it erect (standing upright). However, there needs to be a balance between the pressure exerted on the cell wall and the rigidity of the cell wall, as excess pressure can cause bursting of the cell while less pressure can make the cell flaccid.
Describe Turgor Pressure in your own words:
DRAW AN EXAMPLE OF EACH TYPE OF CELL BELOW:
Cell with Low Turgor Pressure (Flaccid) Cell with Turgor Pressure (Turgid)
PLANT ADAPTATIONS:
Food Storage- some plants have structures called
bulbs that allow for storage of extra energy.
· Examples (which examples you recognize):
· Why might some plants store extra food underground
instead of above ground
Seed Dispersal- plants cannot move from place to place and need to rely on the wind and animals to spread their seeds to other areas.
· What examples do you recognize?
· Which types of seeds to the right do you think are spread
(dispersed) by the wind?
· Which types of seeds to the right do you think are spread by
animals?
Pollination- in order to reproduce plants need their pollen taken from their anther to their stigma or the stigma of another flower to fertilize the flower.
· What types of insects help pollinate flowers?
· What structure does these flowers have that
might help attract pollinators?
· Predict: What mouth shape would the pollinator need to
access the nectar within these flowers?
Leaf Shape/Structure-Plants live in many different
environments. Plant leaves can help a plant adapt to
climate and temperatures of an area.
· Describe some of the differences in the leaves to the right.
· Which leaf structures to the right might be helpful in gathering
more light for the plant and photosynthesis?
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Updated 11/19/10