amoeba

Question 1

size of ameoba

Answer 1

0.3 mm across

Question 2

what environment are they found in

Answer 2

Lives in not large aquatic environments like ponds where it moves around on the surfaces of stones and weeds
Some species live in damp soil

Question 3

structure

Answer 3

Unicellular
Nucleus and cytoplasm
Cytoplasm bounded by a very thin cell membrane and divided into two parts
Outer part – ectoplasm clear and jelly like
Thinner layer clearer gel like found near cell membrane
Water from surrounding environment flows through ectoplasm by osmosis

Inner part – endoplasm granular and runny
More fluid darker towards interior of amoeba
By pushing endoplasm towards cell membrane amoeba causes body to extend and move along where it uses this method to consume food – pseudopodia
Cytoplasm releases digestive enzymes
Various structures float around in endoplasm – food vacuole which contain tiny organisms which the amoeba has eaten

Question 4

contractile vacuole

Answer 4

collects unwanted water from inside the cell and every now and then discharges it to the outside so amoeba does not burst

Question 5

what are amoeba small enough for

Answer 5

gas exchange and excretion to take place by simple diffusion

Question 6

why are amoeba constantly changing shape

Answer 6

cell membrane is thin and elastic and Fluid endoplasm flows around inside it
Ability to change shape provides it with a special method of locomotion

Question 7

how does amoeba reproduce

Answer 7

splits into two

Question 8

disease by amoeba

Answer 8

Amebiasis