Plants and Photosynthesis Flashcards
What are plants made out of? Smallets to largest
Cells, Tissue, Organ, Organ System, Organism
What is epidermal tissue?
Covers the whole plant like skin, with waxy cuticle. Protective layer reducing water loss through transpiration.
What feature does the upper epidermis have?
It is transparent to allow light to pass through it.
What is palisade mesophyll tissue?
Part of the leaf where photosynthesis happens. Contains chlorophyll.
What is spongy mesophyll tissue?
Loosely packed layer of cells in a plant with big air spaces to allow gas exchange in cells through diffusion
What is xylem and phloem?
Vascular tissues in plants that transport water, nutrients and sugars.
What is meristem tissue?
Unspecialised cells that are responsible in growth, able to become different types of plant cells.
What is a xylem?
Dead cells that transport water and nutrients through plant.
What is transpiration?
Movement of water from the roots through the xylem and lost from leaves.
What does phloem transport?
Transports glucose from leaves up and down plant.
What is translocation?
Process of transporting glucose around the plant.
What is stomata?
Stomata are tiny holes or pores in surface of plant leaves and stems. They allow Carbon Dioxide to diffuse directly into the leaf for photosynthesis.
What are guard cells?
Specialised epidermal cells that surround each stomata (two per stomata) and control opening and closing of stomata depending on environmental conditions.
When are the guard cells open?
When plant is full of water guard cells become plump and turgid (swollen), making stomata open
When are the guard cells closed?
When plant is short of water, guard cells lose water and become flaccid, closing stomata. Also, close at night to prevent water loss - no photosynthesis during night.
Give process of transpiration
Water is lost through leaves by stomata, more water taken from transpiration stream through roots back to leave - process restarts - constant stream of transpiration
Why does transpiration occur?
Side effects of having the stomata open for diffusion as water is lost through the small holes.
What is rate of transpiration affected by?
-Light intensity: greater intensity = faster rate
-Temperature: higher temp = faster rate
-Air flow: better flow = faster rate
-Humidity: more humid = slower rate
How does light intensity affect transpiration?
When it’s brighter, stomata always open, so letting water out as well as gas exhange. At night little transpiration as stomata closed.
How does temperature affect transpiration?
The heat gives energy to water particles, making them more likely to evaporate out of stomata.
How does air flow affect transpiration?
No wind means water particles surround leaf - high concentration of water in and outside leaf reduces rate of diffusion. If good air flow, particles blown away making low concentration outside and increasing rate of diffusion.
How does humidity affect rate of transpiration?
Dry air = faster because of water concetration, like air flow.
What is photosynthesis?
Process in which plant uses Carbon Dioxide and water to make oxygen and glucose using sunlight to convert.
Where does photosynthesis take place?
Takes place in chloroplasts because they contain chlorophyll, which is a green pigment that absorbs light.
