3.1 (P2) Exchange Systems In Plants Flashcards Preview

AQA GCSE - Biology > 3.1 (P2) Exchange Systems In Plants > Flashcards

Flashcards in 3.1 (P2) Exchange Systems In Plants Deck (18)
Loading flashcards...
1

How does carbon dioxide enter leaves?

Via diffusion through the stomata

2

Where are water and mineral ions absorbed?

By the roots

3

How is the surface area of roots increased?

Root hair cells

4

How is water taken into and transported around a plant?

Via osmosis through the roots

Transported up by Xylem

5

What are Xylem?

Dead cells forming a hole like tube

6

How are mineral ions taken into and transported around a plant?

Via active transport through the roots

Transported around by Phloem

7

What is the purpose of Phloem?

They transport and direct minerals and nutrients where they need to be as they have small perforated holes allowing movement

8

How does a high concentration of mineral ions inside the plants affect water movement?

When active transport takes place in the roots there is now a higher concentration of ions inside
If there is a higher concentration of minerals ions inside there is a lower concentration of water inside
This helps bring more water in via osmosis as there is a steeper concentration gradient

9

What is transpiration?

The process by which moisture is carried through plants and then evaporated from the leaves

10

How much water is lost by evaporation?

90% lost
10% used in photosynthesis

11

What is a constant water flow useful for?

Turgidity
Photosynthesis
Steep concentration gradient

12

What are stomata?

Holes in the leaf that allow gases to be transferred

13

What are the stomata protected and controlled by?

Guard cells

14

What leaves via the stomata?

Oxygen and water vapour

15

Where is there more stomata? Why?

Underneath the leaf (lower epidermis)

So they lose less water (needed for turgidity)

16

What are guard cells like when sunny? Dark?

Sunny - swollen causing the stomata to be open

Dark - shrunken causing the stomata to be closed

17

How are leaves adapted for efficient gas exchange?

Large surface area: flat shape and air spaces within

High concentration gradient: constant flow of water internally, constant flow of air externally

Short diffusion distance: the leaf is a few cells thick

18

What factors affect transpiration?

Dry and windy
Steeper concentration gradient (moist inside and dry outside)

Hot
Evaporation happens faster