The World of Plants

Variety

Use

Commercial exploitationNeed for maintaining variety

Living Things

Plant Kingdom

Do not produce seeds Produce seeds

Gymnosperms

Angiosperms

Algae Fungi Mosses Ferns

ConifersMonocotyledon Dicotyledon

Variety of plants

Advantages of having a wide variety of plants

Food

Medicine

Poppy

Foxglove

Mandrake

Rosy periwinkle

Medicinal plants

common common namename

poppypoppy foxglovefoxglove mandrakemandrake rosy rosy periwinklperiwinkl

ee

scientific scientific namename

drug drug extractedextracted

use of use of drugdrug

Papaver somniferum

Digitalislanata

Mandragoraofficinarum

Catharanthusroseus

morphine digitoxin hyosycamine vincristine

relief of pain

treatment of heart disease

sedation of patient before

operation

treatment of

leukaemia

plantplant Plant Plant organ organ eateneaten

ProteiProtein (g)n (g)

Fat Fat

(g)(g)Carbo-Carbo-hydrathydrat

ee

(g)(g)

CalciuCalciumm

(mg)(mg)

Iron Iron

(g)(g)Vit AVit A

(mg)(mg)Vit CVit C

(mg)(mg)

cabbagcabbagee

leafleaf

carrotcarrot rootroot

orangeorange fruitfruit

peapea seedseed

potatopotato tubertuber

soyasoya bean bean seedseed

wheatwheat seed seed graingrain

Class of food (all values per 100g of edible food

1.5

0.7

0.8

6.0

2.1

41.0

11.7

0

23.9

1.7

0

0

0

0

5.8

10.7

20.1

13.5

69.6

8.5

5.4

65.0

50.0

42.8

14.2

7.1

210.7

35.7

1.0

0.7

0.3

1.7

0.7

7.1

3.9

0

2

0

0

0

0

0

60.2

6.1

50.1

25.0

17.8

0

0

Possible consequences to man and other animals of a reduction in the variety of species

Ecological loss

Tropical rain forest

Loss of rainforest due to logging

Plantations e.g. pineapple

Destruction of the rainforest leads to loss of habitat

Tropical rain forests cover 6% of Earth’s land

They are estimated to contain half or more of all existing species of plants, animals and micro-organisms

When cleared, the ecosystem and its wide variety of interdependent species are lost forever

For every plant species that becomes extinct through man’s activities, several animal species that were dependent on the

plant for food and habitat are threatened and may become extinct

Animals nearing extinction

Brazil’s muriqui monkey

Kagu bird of New Caledonia

Birdwing butterfly of Papua New Guinea

Possible solutions

‘debt-payment-for-nature’ exchange

donations from conservationists being used to settle developing countries’ international debts

in exchange for

binding promises that these countries will create permanent reserves of tropical rain forest

Loss of future applications of plants Medicinal plants

More than 40 species of flowering plants have already provided mankind with medicines

Tropical rain forests are the Earth’s main source of plants containing chemicals of possible medicinal use in the future

It is thought that at least 2000 different plant species may contain anti-cancer properties

Most of these plants have not been studied in detail

Clearing rain forests and the subsequent loss in the variety of species means losing forever these plants and their potential

medicinal value in combating disease

Genetic storehouse

Over 70% of present day American maize plants are genetically identical

If a new disease arrives they could all be affected

American Maize Plants

A wild form of maize has been discovered in Mexico that is perennial and is resistant to many diseases

Mexican Maize plants

Geneticists are trying to introduce these useful characteristics into modern maize by cross-breeding

In future it will not be possible to introduce new beneficial characteristics into crop plants from wild varieties if they are lost by people destroying their habitats for quick commercial gain

It is essential that we conserve a wide variety of strains of each plant species to provide a genetic storehouse

Specialised uses of plants

Edible oils from plants

Olive oil Corn oilSunflower oil

Specialised uses of plants

The rape plant is a member of the cabbage family.Its leaves provide forage for farm animals such as sheep.Its tiny black seeds contain oil used in lubricants, metal tempering, and foodstuffs

Rapeseed oil

Specialised uses of plants Cotton

A cotton seed bears a mass of ‘hairy’ fibres which act like a parachute during wind dispersal of the seed

A group of seeds with their fibres entangled in a fibrous mass is called a cotton boll

The seeds are separated from their fibres

Oil and protein for animal feed are extracted from the seeds.

The fibres are spun (twisted to give strength) into yarn (thread)

The yarn is then woven into cloth (cotton)

Cotton is a cheap, hardwearing absorbent material. It is particularly useful for mixing with synthetic fibres to make a wide variety of useful fabrics

many uses

alginates

Large brown seaweed

filmforming

gellingand

binding

emulsifyingand

stabilising

thickening

toothpasteshampoo

Hand creamIce cream

polishemulsion

paint

jellytabletsdental

impressions

sausage casings

transparentfilm

washable wall

papers