4.1 Species, Communities and Ecosystems

Question 1

Species

Answer 1

a group of organisms that can interbreed and produce fertile offspring.

Species possess similar physiological, morphological and behavioural characteristics. Are genetically distinct from one another and have a common phylogeny. Asexually reproducing organisms are classified based off appearance and biochemical similarities.

Question 2

Population

Answer 2

a group of organisms of the same species living in the same area at the same time and that are capable of interbreeding

Question 3

Community

Answer 3

a group of populations living and interacting with each other in a habitat

Question 4

Ecosystem

Answer 4

a community and its abiotic (non-biological) environment.

Question 5

Biomes

Answer 5

are regions of the world with similar climate (weather, temperature), animals and plants.

Question 6

Biosphere

Answer 6

total of all areas where living things are found; including deep ocean and the lower part of the atmosphere. The biosphere is a relatively thin layer associated with the surface of the earth.

Question 7

Abiotic Factors

Answer 7

physical factors (non-living) environment

Question 8

Biotic Factors

Answer 8

the living environment

Question 9

Habitat

Answer 9

the environment in which individuals of a certain species can usually be found. The place where organisms live.

Question 10

Hybrids

Answer 10

are organisms that are combined from 2 different species, usually infertile. Plants hybridise more readily than animals and hence there are a lot more.

Question 11

Autotroph

Answer 11

an autotroph is a producer that makes organic molecules from inorganic molecules using light and chemical energy. They synthesise organic molecules from simple inorganic substances e.g CO2. Obtain inorganic nutrients from the abiotic environment.

Question 12

Heterotroph

Answer 12

A heterotroph is a consumer that obtains organic molecules from other organisms. They feed on living organisms by ingestion.

Question 13

Decomposer

Answer 13

are heterotrophic organisms that derive energy from non-living organic matter. Decomposers are important in cycling inorganic chemicals.

Question 14

Detritivore

Answer 14

are heterotrophs that obtain organic nutrients from detritus by internal ingestion, they are often eaten by consumers.

Question 15

Saprotroph

Answer 15

are heterotrophs that obtain organic matter from dead organisms by external ingestion e.g by secreting enzymes onto the matter.

Question 16

Mesocosm

Answer 16

is a model mini-ecosystem that seeks to show that ecosystems have the potential to be sustainable over a long period of time. They are used for experiments as the conditions can be controlled.