Unit 3 Flashcards
Plant Physiology
What is the role of the phloem?
Carries the products of photosynthesis to other parts of the plant.
What are the features and adaptations in an insect-pollinated flower?
-Large, brightly colored petals to attract insects
-Large sticky pollen grains to stick in the insects’ bodies
-Contain nectar as a ‘reward’ for insects
What is phototropism?
The growth of a plant in response to the direction of light.
Where are ova produced in the flowers?
In the ovules in the ovaries.
What are the 2 types of cells found in the mesophyll layer?
spongy and palisade cells.
what is geotropism?
The growth of a plant in response to the direction of gravity.
How does a pollen grain reach an ovum so fertilisation can take place?
1) Pollen grains from another flower land on the stigma
2) The pollen grain grows a pollen tube down the style into the ovary
3) The tip of the tube dissolves to allow the pollen grain to move out of the tube and into the ovule to fertilise
What are the 4 factors that affect transpiration?
-Light intensity (increase)
-temperature (increase)
-Humidity (decrease)
-Wind speed (increase)
Which layer forms them main gas exchange surface of the leaf?
Spongy mesophyll layer.
How do you test for starch in leaves?
1) Place leaf in boiling water for 30 sec to dewax it
2) Place leaf in boiling ethanol to remove chlorophyll (Bunsen burner off)
3) Wash leaf with cold water and place it on a tile
4) Add a few drops of iodine to the leaf
5) Any parts of the leaf that contain starch will turn blue-black
What does turgid mean?
When a plant cell has a high internal pressure, which makes to cytoplasm push against the cell wall.
What is the response of the roots to gravity?
Positive geotropism
What are the male and female gametes for plants
pollen grains and ova
What is the role of the xylem?
Supplies the leaf with water and mineral ions.
What is the response of shoots to light?
Positive phototropism
What are the features and adaptations in an wind-pollinated flower?
-Small, not brightly colored petals
-Small, smooth grains to be carried in the wind
-Feathery stigma to catch pollen grains in the wind
Why is turgor important for plants?
So neighboring cells that have lower water potential can absorb water due to osmosis. This happens to many cells so that water can move across a plant tissue.
Where are pollen grains produced in the flowers?
In the anthers of the stamens.
What is the role of the cuticle in the upper and lower epidermis?
Reduces water loss by evaporation and acts as a barrier against microorganisms.
What are the conditions required for germination?
-Warm temperatures, so that enzymes can work efficiently
-Water, for chemical reactions to take place
-Oxygen, for respiration
Why is the upper epidermis transparent?
To allow light to pass through to the chloroplasts in the palisade layer.
