Biology Topic 2 Higher Content Flashcards
(11 cards)
1
Q
How are the lungs adapted for gas exchange?(6)
A
- avleoli increase surface area for diffusion
- alveoli have thin walls so there is a short diffusion pathway
- alveoli are surrounded by capillaries
- capillaries have thin walls
- there is a constant flow of blood
- there is a constant supply of oxygen to maintain the concentration gradient
2
Q
How does humidity affect the rate of transpiration?
A
- the higher the humidity the lower the concentration gradient
- resulting in slower diffusion
3
Q
How does wind affect the rate of transpiration?
A
- more wind causes water to be blown away from the surface of leaves
- this means there is less water vapor surrounding the leaves
- therefore there is a higher concentration gradient
- leading to faster diffusion
4
Q
How does light intensity affect the rate of transpiration?
A
- greater light intensity increases the rate of photosynthesis
- thiscauses the stomata to open to allow in more CO2 for photosynthesis
- this causes more water to be lost from the stomata
5
Q
What is the epidermal tissue?
A
- outer layer that covered the whole plant
- it is covered in a waxy cuticle
6
Q
What is the palisade mesophyll?
A
- the second layer
X it constants lots of chloroplast for photosynthesis
7
Q
What is the spongy mesophyll?
A
- 3rd layer
- has lots of air spaces for gas exchange
8
Q
What are the features of the xylem?
A
- made up of dead cells
- transports water
- It is strengthened by lignin
- lignin makes it waterproof
9
Q
What are the features of the phloem?
A
- made of living cells
- has end wales that contain pores
- contains cytoplasm
- transports sugars
10
Q
What is meristem tissue?
A
It is stem cells that can differentiate into any plant cell
11
Q
Where is meristem tissue found?
A
In the tips of roots and shoots
