M2 Q2 - Nutrient And Gas Requirements Flashcards
(13 cards)
Autotroph
An organism that produces its own nutrients
Using external energy to turn in inorganic compounds into organic compounds
Heterotroph
An organism that cannot produce its own food
Autotroph structure and function
The majority of autotrophic organisms are plants.
- Vascular plants: have a transport system to move substances from one part of the plant to another (ferns, conifers)
- Non-vascular plants: they do not possesses this transport system (mosses, liverworts)
The shoot system
Everything above the ground, including the stem, leaves and any buds or flowers
The root system
Everything below the ground, including the roots or tubers
Leaf system
- Epidermis
- Cuticle
- Stomata
- Mesophyll
- Vascular bundles
Epidermis
A single layer cells on the outside of the leaf
Its job is to protect the cells inside the leaf whilst preventing water loss.
Cuticle
The outside of the epidermis is covered in a thin waxy layer that is waterproof called the cuticle
Stomata
To regulate exchange of gases there are stomata within the epidermis. It opens and closes to allow gas exchange.
Mesophyll
Mesophyll is the middle part of the leaf, where most photosynthesis happens. It contains two layers:
- Palisade mesophyll
- Spongy mesophyll
Vascular bundles
Vascular bundles are the plant’s transport system. Contains:
- Xylem: carries water and minerals from roots to leaves
- Phloem: carries sugars made in leaves to other parts of the plant
Root system
It’s job is to absorb water and minerals from the soil to anchor the plant into the soil and store nutrients:
- Epidermis
- Cortex
- Vascular bundles
Gas exchange in plants
The main sight of gas exchange are the stomata in the leaves. A pair of guard cells open and close the stoma, by changing how much water they have inside of them.
Turgid: stoma open
Flaccid: stoma closed
When gases have diffuse through the stoma, they can move into the spongy mesophyll and diffuse through cells
