Chapter 18: Biodiversity

Question 1

Explain what is ecosystem.

Answer 1

It is a community of organisms in a self-contained area.

It is a self-sustaining unit, where there is energy flow where nutrients are recycled.

It consists of biotic and abiotic components, which interact with each other.

Question 2

Explain what is niche.

Answer 2

Role of organism in an ecosystem, including where it lives and how it obtains its energy.

Question 3

Explain how variation in ecosystems contribute to biodiversity.

Answer 3

Different habitats means there’s many different species with different niches adapting to different selection pressures such as temperature.

Question 4

What does a higher Simpson’s Diversity Index mean?

Answer 4

Greater species evenness = biodiversity

Question 5

Explain how the term biodiversity can be explained at different levels.

Answer 5

Go from wider to narrow
- Diversity of ecosystems
- Diversity of species
- Relative abundance of each species
- Genetic diversity within a species

Question 6

Describe actions by government that can protect endangered species.

Answer 6

• Ban the animal product
• Ban hunting
• Detection methods such as extra rangers
• Enforcement measures such as prisons
• Raise public awareness and education
• Create national parks

Question 7

How does zoos protect endangered animals?

Answer 7

Captive breeding
Establish reserves
Education
Research
Healthcare qualified
Release into wild

Question 8

List methods of assisted reproduction.

Answer 8

IVF
Embryo transfer
Surrogacy
Artificial insemination

Question 9

Outline characteristics of organisms in Archaea.

Answer 9

Mostly unicellular
No nucleus, so circular DNA
No membrane-bound organelles
Cell membrane composition different from bacteria, has unique lipids
Has 70s ribosomes
Cell wall present, BUT DO NOT have peptidoglycan
Cells divide by binary fission
Some have histones associated with DNA

Question 10

Function of seed banks.

Answer 10

Seed banks
- Collects a variety of seeds and stores them for long-term and maintain dormancy by storing them frozen

• Seeds regularly tested for viability, and preserves genetic material so maintain biodiversity especially can be used after disaster
• Also can use for research

Question 11

Outline characteristics of organisms in Eukarya.

Answer 11

Has nucleus so linear DNA which is associated with histones
Has double-membrane organelles such as mitochondria
Has 80s ribosomes, but 70s ribosomes in chloroplast and mitochondria
Unicellular, colonial and multicellular
Reproduction can be asexual and sexual

Question 12

Outline characteristics of organisms in Bacteria.

Answer 12

Unicellular and divides by binary fission
No nucleus therefore circular DNA with histone-like proteins associated
No membrane bound organelles such as mitochondria
70s ribosomes
Cell wall made of peptidoglycan
Can have different shapes such as sphrerical or corkscrew

Question 13

Explain the function of botanic gardens.

Answer 13

Collects seeds from the wild from many countries especially areas at risk from climate change

In botanic gardens, these seeds are planted to increase plant number, tissue cloning can also occur

Store these in seed bank to maintain genetic diversity for i) research ii) conserve habitats iii) restore habitats iv) education v) raise funds

Question 14

Explain what is meant by biodiversity.

Answer 14

Variety within ecosystem
Variety of different species
Relative abundance of each different species
Genetic variation within each species

Question 15

Outline the kingdom Fungi.

Answer 15

Some are unicellular

Has hyphae that grows from mycelium

Has multinucleate parts

Reproduces using spores

Cell walls made of chitin

Heterotrophs: use organic compounds made by other organisms as source of energy and molecules for metabolism by digesting decaying matter extracellularly

Question 16

Outline the kingdom Animalia

Answer 16

Multicellular, which then has specialised cells which can differentiate into organs

Some are motile

Some cells have cilia

They are heterotrophs, have wide range of feeding mechanisms

Wide range of body forms, communication done through nervous system and chemical signalling

Question 17

Problems of breeding programmes for mammals.

Answer 17

May be stressed in captivity

Mate may be rejected

Reproductive cycles may be disrupted

Question 18

Outline features of viruses

Answer 18

Not cellular

Contains DNA, can be single or double-stranded

Core surrounded by capsid and may have lipoprotein

No metabolism/respiration, immobile, not thought to be living

Pathogens, and have proteins to help with infection

Reproduce in host cells and are highly specific to host cells

Size around 20-750nm

Question 19

Outline function of non-government environmental organisations.

Answer 19

Organisations such as WWF and IUCN does many things:
i) Raises funds and conducts research
ii) Influence the government to band hunting, legislate trade in wild species, hold protest against the government and even raise awareness
iii) Conserve species and monitor endangered species
iv) Promote coexistence of wildlife with people

Question 20

Describe how random sampling can be used to assess distribution and abundance of plants in the area.

Answer 20

The area is marked out as grid, then coordinates for the investigation is obtained using random number generator

Use equal-size quadrats on the random co-ordinates

Species identified within quadrat then count number within quadrat, use the Braun Blanquet, then repeat sampling so calculate the means for more accuracy.