Mineral Ions And Water

Question 1

Role of magnesium

Answer 1

Plants: To make chlorophyll
Mammals: for bones

Question 2

Role of iron

Answer 2

Animals: component of haemoglobin

Question 3

Phosphate

Answer 3

Plants and animals: to make nucleotides (ATP)

Question 4

Role of calcium

Answer 4

Animals: structural component of bones and teeth
Plants: component of cellulose cell walls (middle lamella is made of calcium pectate)

Question 5

High specific heat capacity of water

Answer 5

Large amounts to heat energy is needed to raise its temperature,
Preventing large fluctuations in water temperature,
:. Keeps aquatic habitats stable so that they do not have to adapt to extremes of temperature

Question 6

High latent heat of vaporisation of water

Answer 6

Lots of heat energy is required to change it from a liquid to a vapour,
Important for temperature control as heat is used to vaporise water from sweat on skin or from a leaf’s surface,
As the water evaporates, the body cools

Question 7

Cohesion of water

Answer 7

Water molecules are attracted to each other due to its dipole structure,
The molecules stick together in a lattice,
:. Allows for columns of water to be drawn up xylem vessels in plants

Question 8

High surface tension of water

Answer 8

In a pond, cohesion between water molecules at the surface produces surface tensions,
So the body of organisms such as pond skaters are supported and they can make it their habitat

Question 9

High density of water

Answer 9

Ice is less dense than water,
It is a good thermal insulator as it prevents large bodies of water from losing heat and freezing completely,
:. Organisms beneath survive

Question 10

Transparency of water

Answer 10

Allows light to pass through,
So aquatic plants can photosynthesise effectively