Species and Ecosystems (4.1)

Question 1

Species

Answer 1

A group of organisms that can inter-breed and produce fertile offspring.

Question 2

Community

Answer 2

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

Question 3

Ecosystem

Answer 3

A community and its abiotic (non-living) environment.

Question 4

Biosphere

Answer 4

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

Question 5

Population

Answer 5

A group of organisms of the SAME species living in the SAME area at the SAME time that are capable of inter-breeding.

Question 6

Biomes

Answer 6

Regions of the world with similar climates (weather/temperature), animals and plants.

Question 7

A Species is made up of organisms that:

Answer 7

• Possess similar physiological, morphological and behavioural characteristics.
• Are capable of inter-breeding and producing fertile offspring.
• Are genetically distinct from one another.
• Share a common phylogeny (evolutionary history).

Question 8

Species: Exceptions to the definition

Answer 8

• The concept of a species being able to inter-breed does not apply to extinct forms so they are instead classified on morphological grounds.
• Asexually reproducing organisms do not breed with each other so are classified on appearance and biochemical similarities.

Question 9

Biotic Factors

Answer 9

The living environment eg. predators, parasites, human influence, disease

Question 10

Abiotic Factors

Answer 10

Physical/chemical (non-living) factors of an environment eg. humidity, wind, temperature, soil type, salinity, carbon dioxide levels

Question 11

Environment

Answer 11

The biotic (living) and abiotic (non-living) factors that affect organisms.

Question 12

Habitat

Answer 12

The environment where an individual of a certain type of species can usually be found. The place where an organism lives.

Question 13

Hybrids

Answer 13

Organisms combined from two different species. Hybrids are usually infertile however there are some exceptions.

It is also important to note the plant species hybridize more easily than animal species so the resulting hybrids are more likely to be fertile.

Question 14

Feeding Methods: Detritivore

Answer 14

Ingest non-living organic matter.

Heterotrophs that obtain organic nutrients from detritus (non-living organic matter, dead plants and animals including faeces) by internal digestion. Detritivores are important decomposers in the ecosystem as they are used for a source of food by consumers.
Examples of Detritivores: are earthworms and woodlice.

Question 15

Feeding Methods: Saprotroph

Answer 15

Heterotrophs that obtain organic nutrients from dead organisms by external digestion eg. by secreting digestive enzymes onto the matter, then absorbing the organic compounds.
Examples of Saprotrophs: Saprophytic bacteria, fungi and protozoa.

Question 16

Feeding Methods: Consumers

Answer 16

Consumers ingest organic matter that is living or has recently been killed.
- Primary Consumers eat producers. Examples: Herbivores
- Secondary Consumers eat other consumers. Examples: Carnivores and omnivores.

Scavengers are a type of consumer. They don’t tend to kill but rather, feed on the matter other species have killed. Examples: Vultures and hyenas.

Question 17

Feeding Methods: Autotroph

Answer 17

Autotrophs are producers.
An organism that synthesises its organic molecules from simple inorganic substances (eg. carbon dioxide or nitrates) using light or chemical energy.
Examples: algae and grass.

Question 18

Feeding Methods: Heterotroph

Answer 18

An organism which obtains organic molecules from other organisms. “other source feeding”

They feed on living organisms by ingestion.
Examples: cows, mice and whales.

Question 19

Feeding Methods: Decomposers

Answer 19

Heterotrophs that derive energy from non-living/dead organic matter. There are two types of decomposers: detritivores and saprotrophs. Decomposers are good sources of energy for other consumers and are also useful for cycling inorganic chemicals such as nitrogen and phosphorus.

Question 20

Mescocosm

Answer 20

A small area where parts of the natural environment are kept under controlled conditions.

Question 21

Morphology

Answer 21

The form or structure of organisms

Question 22

Nutrient Cycling

Answer 22

The supply of inorganic nutrients is finite and is in limited supply so they are recycled.

*Diagram