3.5 Symbiosis Flashcards Preview

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Flashcards in 3.5 Symbiosis Deck (26)
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1
Q

What is co-evolution?

A

some organisms depend on other organisms because they form a partnership leading to co-evolution
this means that they evolve together over millions of years and the evolutionary change of one organism is triggered by its interaction with the other

2
Q

how are symbiotic relationships formed?

A

through coevolution

3
Q

What is symbiosis?

A

symbiosis means ‘living together’ and refers to an intimate relationship between organisms from two

4
Q

what are the different types of symbiosis?

A

paratism

mutualism

5
Q

REMEMBER!

A

other living things are an important feature of an organisms ecosystem because organisms depend on one another for food or a habitat for example

6
Q

what is a parasite?

A

a parasite lives in or on the body of another organism, which is known as the host, and gains energy or nutrients from it
the parasite gains from the relationship and the host is harmed due to loss of valuable resources

7
Q

what are ectoparasites?

A

parasites such as ticks, fleas, leeches and lice live on the surface of the hosts body and are called ectoparasites

8
Q

what are endoparasites?

A

parasites such as tapeworms, roundworms, flukes, bacteria and viruses live inside the body of the host and are called endoparasites

9
Q

Why can the majority of parasites not survive in the absence of a host and what are they called?

A

since they are adapted to live in or on a host, they may have lost some of the organs needed to survive on their own. these are called obligate parasites

10
Q

TOPTIP

A

parasites fall into two main groups:
obligate parasites need a host to survive
facultative parasites are able to survive outside a host

11
Q

What are tapeworms?

A

tapeworms attach themselves to the sides of the intestines of animals and obtain partially digested food from their hosts

12
Q

what are fleas?

A

fleas bite the skin of their host and gain energy by sucking their blood
many types of parasites carry and transmit disease in this way

13
Q

How can parasites be transmitted from one host to another?

A

direct contact
via resistant stages
via a vector

14
Q

Explain transmission by direct contact?

A

this is when a parasite is passed directly from one host to another when two hosts come into close physical contact with each other
head lice can only move from one human head to another by direct contact

15
Q

Explain transmission by resistant stages?

A

some parasites, for example, protozoa, have resistant or resting stage (cysts or oocysts) which can resist drying out and other stresses such as temperature extremes and harsh chemicals
they can survive without a host for a period of time

16
Q

What is a vector?

A

a vector is an intermediate organism that transfers a parasite from one host to the next
e.g. a species of mosquito which transfers the protozoan parasite plasmodium which causes malaria, from one human host to another

17
Q

What is a secondary host?

A

a secondary or intermediate host is necessary for some parasites to complete their lifecycle
asexual reproduction or the development of larval stages of the parasite may occur in the secondary host
humans are the secondary hosts for malarial parasites

18
Q

What is mutualism?

A

both species within a mutualistic relationship benefit in terms of food and energy and are usually compatible in terms of physical structures due to the process of co-evolution

19
Q

Example 1 Herbivores

A

herbivores must get their energy from the plant material which they eat
however, their digestive systems do not produce cellulase, the enzyme necessary to digest cellulose in plant cell walls
they need the help of cellulose digesting bacteria and protozoa which live in their digestive system
In return these microorganisms get food from the gut of the herbivores

20
Q

Example 2 Coral Polyps

A

coral polyps are animals and they form a mutualistic relationship with zooanthellae algae which live within the polyp cells
coral providers the algae with carbon dioxide for photosynthesis and other wastes including water and ammonium compounds
they algae provide the coral with sugar and oxygen

21
Q

Explain coral bleaching?

A

Rising sea temperatures, perhaps due to global warming, causes the loss of the unicellular, symbiotic zooanthelle from coral species.
the coral dies and turns white-coral bleaching

22
Q

Example 3 Clownfish and sea anemones?

A

clown fish live among the stinging tentacles of sea anemones.
a thick mucus layer on the skin protects the fish from stings, which deter predators
the sea anemone is protected as the presence of the clownfish deters the butterflyfish which eat sea anemones

23
Q

Example 4 Oxpecker bird?

A

the oxpecker bird feeds on the small insects in the coat of a buffalo
the buffalo benefits from having pests removed while the oxpecker bird exploits a plentiful food source of food

24
Q

Example 5 Lichens?

A

lichens are a product of a mutualistic relationship between an algae and a fungus which grow together in one unified structure
algae receive nutrients from the fungus in turn receives glucose from the photosynthetic algae

25
Q

What is the evolution of mitochondria and chloroplasts?

A

It is thought that mitochondria and chloroplasts in eukaryotes evolved from free living bacteria (prokaryotes) which were engulfed by other cells, forming a mutualistic relationship

26
Q

DONT FORGET

A

prokaryotes do not have membrane bound organelles such as a nucleus, chloroplasts or mitochondria
plant, animal and yeast cells are all eukaryotes and have a membrane-bound nucleus and other membrane-bound organelles such as mitochondria and chloroplasts