Water

Question 1

Heritable changes in genes occurring through natural selection

Answer 1

Adaptation

Question 2

Non heritable changes in gene expression. Usually reversible

Answer 2

Acclimation

Question 3

What 4 things is water required for

Answer 3

Maintaining cell turgidity
Photosynthetic processes
Transpiration
Translocation of solutes

Question 4

What is transpiration

Answer 4

Unidirectional movement of water into roots up through stems to leaves into atmosphere

Question 5

What % of precipitation does transpiration account for

Answer 5

40%

Question 6

How many litres of water does a mature oak transpire per year

Answer 6

150,000

Question 7

How many litres does an acre of corn transpire per year

Answer 7

15,000

Question 8

What are walls of xylem made from

Answer 8

Lignin - a long chain polymer

Question 9

Plant type that has scattered vascular bundles

Answer 9

Monocot

Question 10

Plant type with rings of vascular bundles

Answer 10

Dicot

Question 11

Plant type with parallel leaf veins

Answer 11

Monocot

Question 12

Plant type with branching veins in leaves

Answer 12

Dicot

Question 13

Strong outer protective layer in roots, regulates mineral uptake

Answer 13

Epidermis

Question 14

Main body of root providing turgidity of structure allowing roots to grow down

Answer 14

Cortex

Question 15

Single layer of cells controlling entry to xylem

Answer 15

Endodermis

Question 16

Involved in root development and able to produce new roots

Answer 16

Pericycle

Question 17

Which route does water take through only cytoplasm into xylem

Answer 17

Symplastic

Question 18

Which route does water take involving osmotic movement through cell walls

Answer 18

Apoplastic

Question 19

What forces water into symplastic route in the endodermis

Answer 19

Casparian strip

Question 20

Why does the endodermis secret salt into xylem

Answer 20

To ensure water is retained in roots

Question 21

What effect does high rate of photosynthesis have on transpiration

Answer 21

Transpiration is increased

Question 22

Which route of water into xylem is more controlled

Answer 22

Symplastic (through cytoplasm)

Question 23

What do transport proteins and aquaporins do

Answer 23

Facilitate water transport across membranes

Question 24

What effect does warm and dry conditions have on transpiration

Answer 24

Higher rate of transpiration

Question 25

What is cohesion-tension theory

Answer 25

Water molecules held together by strong hydrogen bonds

Loss of water through stomata pulls water up

Question 26

What is the effect on transpiration when humidity increases and why

Answer 26

Transpiration decreases because there’s a lower water potential gradient

Question 27

What is the effect on transpiration when wind velocity increases and why

Answer 27

Transpiration increases because evaporates water quickly

Question 28

What is the effect on transpiration of increased light intensity and why

Answer 28

Trnapsirstion increases because photosynthesis increases and so stomata open

Question 29

What is the effect of increased temperature on transpiration and why

Answer 29

Transpiration increases because higher rate of photosynthesis and evaporation

Question 30

What forests are characterised by cold climate

Answer 30

Boreal

Question 31

What does trapped gas within a xylem result in

Answer 31

Embolisms

Question 32

Why are embolism harmful to plants

Answer 32

Prevent transpiration as cohesion is prevented

Question 33

How do boreal trees prevent embolisms

Answer 33

Narrower xylems

Question 34

What is the trade off of a short narrower xylem

Answer 34

Less efficient in transpiration and more cells required

Question 35

How did embolism-preventative adaptations evolve

Answer 35

Linked to drought resistance as plants radiated northwards there were lower water conditions