2.2 Living Process In Unicellular Organisms Flashcards
How does Amoeba sp. and Paramecium sp. grow? (1 mark)
Synthesises new cytoplasm.
How do Amoeba sp. and Paramecium sp. respond to stimuli such as chemicals, touch or bright light? (1 mark)
Moves away from the stimuli.
How does Amoeba sp. move? (2 marks)
Amoeba sp. moves by extending its pseudopodium (false feet), followed by the flow of cytoplasm into this extending pseudopodium. Its shape changes regularly whenever it faces obstacles.
How does Amoeba sp. reproduce? (3 marks)
Amoeba sp. carries out binary fission which is an asexual reproduction hen the environmental conditions are favourable.
Amoeba sp. carries out spore formation when the environmental conditions are not favourable such as drought, food shortage and low temperatures. The spores will only germinate when the environmental conditions improve.
How does Amoeba sp. carry out the process of nutrition? (2 marks)
-The process of nutrition is phagocytosis. Amoeba sp. approaches the food particle with its pseudopodium which is then followed by the flow of cytoplasm into the extending pseudopodium.
-The food vacuole is then formed in the cell.
-The lysosome combines with food vacuole to release hydrolytic enzyme, lysozyme to hydrolyse the food particle.
-The digested food particle is absorbed into the cytoplasm while the undigested food particle is discharged when the Amoeba sp. moves.
How does Paramecium sp. move? (1 mark)
Paramecium sp. moves by rhythmic cilia beatings.
How does Paramecium sp. reproduce during hot weather? (2 marks)
Paramecium sp. carries out conjugation when the environmental conditions are unfavourable.
Where are Amoeba sp. and Paramecium sp. usually found? (1 mark)
Freshwater ponds and lakes
Compare the components of Amoeba sp. and Paramecium sp. (10 marks)
-Amoeba sp. has pseudopodium while Paramecium sp. doesn’t.
-Paramecium sp. has cilium whereas Amoeba sp. doesn’t.
-Paramecium sp. has oral groove whole Amoeba sp. doesn’t.
-Amoeba sp. has one type of nucleus which is nucleus while Paramecium sp. has two types of nucleus which are micronucleus and macronucleus.
-Both Amoeba sp. and Paramecium sp. have contractile vacuole, food vacuole, ectoplasm, endoplasm, and plasma membrane.
How do Amoeba sp. and Paramecium sp. carry out respiration? (2 marks)
In both species, exchange of oxygen and carbon dioxide gases occur through the plasma membrane by simple diffusion on the surface of the cell.
Explain the process of feeding in Amoeba sp. (6 marks)
-The feeding process in Amoeba sp. is phagocytosis.
-Amoeba sp. extends its pseudopodia (false feet) and engulf the food particle.
-The food is then packaged into a food vacuole.
-Lysosome in the cell combines with the food vacuole and release hydrolytic enzymes lysozyme to hydrolyse the food particle.
-Digested food particles are absorbed into the cytoplasm.
-Undigested food are excreted as waste products.
How does Amoeba sp. and Paramecium sp. discharge undigested food? (2 marks)
Amoeba sp. discharges undigested food when it is moving.
Paramecium sp. discharges undigested food through the anus.
How does Paramecium sp. carry out the nutrition process? (2 marks)
The presence of cilium beat in Paramecium sp. helps transfer food particles into the oral groove.
What is the function of contractile vacuole? (1 mark)
To regulate the water content in the cell.
Explain the reproduction process carried out by Paramecium sp. when the environmental conditions are not favourable. (8 marks)
-Paramecium sp. carries out conjugation when the environmental conditions are not favourable.
-Two individuals from different strains come together and exchange genetic materials between the nuclei.
-The Paramecium cells separate and each can divide to produce four new cells.
-A total of eight daughter cells with different variety of species are formed.
