Unit 2.4 Adaptions For Nutrition

Question 1

Define ‘autotrophic’

Answer 1

Synthesis of complex organic chemical from inorganic substances using an energy source

Question 2

Define ‘photoautotrophic’

Answer 2

Uses light energy to combine inorganic substances into complex organic chemicals

Question 3

Define ‘chemoautotrophic’

Answer 3

Uses chemical energy, from chemicals such as hydrogen sulphide, to combine inorganic substances into complex organic chemicals

Question 4

Define ‘heterotrophic’

Answer 4

Cannot synthesis it’s own complex organic chemicals; it must digest organic chemicals produced by other organisms and use the products of digestion to synthesise their own organic chemicals

Question 5

Saprotrophic/saprobiontic

Answer 5

Extracellular digestion of dead or decayed organic matter: enzymes are secreted by an organism which then digest the organic chemicals of the substrate on which they live. The products of digestion are then absorbed by the saprotroph.

Question 6

Define ‘Holozoic’

Answer 6

Absorption of organic matter followed by internal digestion of the organic chemicals within the organism.
In single celled organisms, organic matter is taken into the cell where intracellular digestion takes place; products of digestion are released and used within the cell and waste / undigested material is released to the outside.
Most multicellular organisms have a digestive system whereby organic matter is ingested and digested extracellularly but still within the organism; products of digestion are then absorbed into cells / transport system and utilised by different parts of the body. Waste / undigested material is released to the outside as faces during egestion.

Question 7

Define ‘parasitic’

Answer 7

Living in or on another host organism, whereby nourishment is obtained from a host organism, usually to the detriment / harm of the host; the host usually derives no benefit.
Ectoparasites live on the outside of a host organism, while endoparasites live inside a host organism, some are intracellular, and others are extracellular.

Question 8

Define ‘symbiosis/mutualism’

Answer 8

Many organisms live in/on other organisms in a relationship that provides benefit to both organisms