2.4 Modes of nutrition

Question 1

what is nutrition

Answer 1

the process by which organisms use nutrients to obtain
- energy to maintain functions of life
- matter to create and sustain function

Question 2

what are the 2 main modes of nutrition

Answer 2

1. autotrophic nutrition
2. heterotrophic nutrition

Question 3

what are the 2 types of autotrophic nutrition

Answer 3

1. photosynthesis
2. chemosynthesis

Question 4

explain autotrophic nutrition

Answer 4

autotrophic = self feeding
autotrophs produce their own food by using inorganic materials

Question 5

explain photosynthesis

Answer 5

light is the source of energy for the production of food
it is used by all green plants, algae and some bacteria.

Question 6

explain chemosynthesis

Answer 6

chemical activity is the source of energy for the production of organic compounds
it is used by autotrophic bacteria

Question 7

what are the 4 types of heterotrophic nutrition

Answer 7

1. holozoic feeders
2. Saprophytes
3. parasites
4. mutualistic feeders

Question 8

what is heterotrophic nutrition

Answer 8

heterotrophic = fed by others
heterotrophs food is processed as it passes along the gut

in advanced organisms(with more varied diet), gutis divided into various parts

Question 9

examples of heterotrophs:

Answer 9

animals
fungi
some bacteria
some protists

Question 10

what are holozoic feeders

Answer 10

nearly all animals
- a method of nutrition which involves digestion of liquid/solid organic material, broken down by digestion

Question 11

What is a holozoic detritivore

Answer 11

obtain energy from dead and decaying material - insects

Question 12

what are saphrophytes

Answer 12

obtain energy from dead and decaying material but DO NOT have a specialised digestive system

Question 13

how do saprophytes feed

Answer 13

by secreting enzymes onto their food OUTSIDE THE BODY.
They then absorb the digested/soluble products across the cell membrane (diffusion).
THIS IS EXTRACELLULAR DIGESTION

Question 14

give examples of saprophytes

Answer 14

all fungi
some bacteria

Question 15

what are parasites

Answer 15

organisms which live on or in another organism(called the host), obtaining nourishment at the expense of the host.
HIGHLY SPECIALISED ORGANISMS - lots of adaptation shown

Question 16

what are ectoparasites

Answer 16

parasites which live on the surface of the host

Question 17

what are endoparasites

Answer 17

parasites which live inside the body of the host

Question 18

what is an example of a ectoparasite

Answer 18

a flea

Question 19

what is an example of a endoparasite

Answer 19

a tapeworm

Question 20

what is mutualism also known as:

Answer 20

symbiosis

Question 21

what is mutualism

Answer 21

a close association between members of 2 species, where both members gain some benefit from the relationship

Question 22

give an example of mutualism/symbiosis

Answer 22

microbes(bacteria) in the gut of sheep/cows.
- herbivores do not produce cellulase which is needed to digest cellulase. Bacteria which live in rumen do produce cellulase.
in return, bacteria gain other digestive products, warmth and protection.