Topic 4.1 Species, Communities and Ecosystems

Question 1

Species

Answer 1

A group of organisms that can potentially interbreed to produce fertile, viable offspring

Question 2

Population

Answer 2

A group of organisms of the same species that are living in the same area at the same time

Question 3

Community

Answer 3

A group of populations living together and interacting with each other within a given area

Question 4

Habitat

Answer 4

The environment in which a species normally lives, or the location of a living organism

Question 5

Ecosystem

Answer 5

A community and its abiotic environment (i.e. habitat)

Question 6

Ecology

Answer 6

The study of the relationship between living organisms, or between living organisms and their environment

Question 7

Autotrophs

Answer 7

Self-feeding - synthesizes its own organic material from inorganic substances. Uses photosynthesis. They are also known as producers

The sun is usually the initial energy source for most communities

Question 8

Heterotroph

Answer 8

Other source feeding - obtains organic material from other organisms as they are unable to produce for themselves

Question 9

Mixotroph

Answer 9

Certain unicellular organisms are able to use both forms of nutrition depending on resource availability

Question 10

Heterotroph - Consumer

Answer 10

Herbivore - Plant
Omnivore - Plant and animal matter
Carnivore - Meat / animal matter

Question 11

Scavengers

Answer 11

Opportunistic animals that feed on dead carcasses rather than hunting live prey

Question 12

Detrivores

Answer 12

Detritivores are a type of heterotroph that obtains nutrients from non-living organic sources, such as detritus and humus

• Detritus is dead, particulate organic matter – such as decaying organic material and fecal matter
• Humus is the term given specifically to the decaying leaf litter intermixed within the topsoil
• Detritivores include dung beetles, earthworms, woodlice, snails and crabs

Question 13

Saprotrophs

Answer 13

Saprotrophs live on (or in) non-living organic matter, secrete digestive enzymes into it and absorbing the products of digestion

Question 14

Nutrient cycle

Answer 14

• Autotrophs obtain inorganic nutrients from the air, water and soil and convert them into organic compounds
• Heterotrophs ingest these organic compounds and use them for growth and respiration, releasing inorganic byproducts
• When organisms die, saprotrophs decompose the remains and free inorganic materials into the soil
• The return of inorganic nutrients to the soil ensures the continual supply of raw materials for the autotrophs

Question 15

Three components required for sustainability in ecosystems

Answer 15

Energy availability
Nutrient availability
Recycling of wastes

Question 16

Mesocosms

Answer 16

enclosed environments that allow a small part of a natural environment to be observed under controlled conditions