Living Processes in Unicellular Organisms

2.2

Living Processes in Unicellular Organisms

Introduction

Unicellular organisms are made up of only one cell.

Amoeba sp.

Amoeba sp. constantly changes its shape when it encounters obstacles.
Amoeba sp. moves by extending out its pseudopodium (false feet) and is followed by the flow of cytoplasm into the extended pseudopodium.
Amoeba sp. responds to stimuli such as chemicals, touch or bright light by moving away from the stimuli.
Amoeba sp. moves towards food by extending its pseudopodium to trap food particles by phagocytosis.
The food vacuole is combined with lysosome.
The food particles are hydrolysed by the enzyme lysozyme in the lysosomes.
The nutrients are absorbed into the cytoplasm.
Undigested food is discharged when the Amoeba sp. moves.
Exchange of oxygen and carbon dioxide gases occur through the plasma membrane by simple diffusion on the surface of the cell.
Ameoba sp. grow by synthesising new cytoplasm.
Waste such as carbon dioxide and ammonia are removed by diffusion.
As Amoeba sp. live in freshwater environments, water will diffuse by osmosis and fill the contractile vacuole.
When the vacuole expands to the maximum size, contraction occurs and water is excreted from time to time.
This process is called osmoregulation.
When the conditions are suitable and there is plenty of food, Amoeba sp. will reproduce via asexual reproduction that is binary fission through mitosis.
However, when the environmental conditions are not suitable, such as dry conditions, low temperature and food shortage, the Amoeba sp. forms spores that will only germinate when the environment improves.

Paramecium sp.

Paramecium sp. moves using rhythmic cilia beats.
Paramecium sp. respond to stimuli such as chemicals, touch or bright light by moving away from the stimuli.
Paramecium sp. the presence of cilium beat helps transfer food particles into the oral groove.
The food vacuole is combined with lysosome.
The food particles are hydrolysed by the enzyme lysozyme in the lysosomes.
The nutrients are absorbed into the cytoplasm.
Undigested food in the Paramecium sp. is discharged through the anus.
Exchange of oxygen and carbon dioxide gases occur through the plasma membrane by simple diffusion on the surface of the cell.
Paramecium sp. grows by synthesising new cytoplasm.
Waste such as carbon dioxide and ammonia are removed by diffusion.
As Paramecium sp. live in freshwater environments, water will diffuse by osmosis and fill the contractile vacuole.
When the vacuole expands to the maximum size, contraction occurs and water is excreted from time to time.
This process is called osmoregulation.
When the conditions are suitable and there is plenty of food, Paramecium sp. will reproduce via asexual reproduction that is binary fission through mitosis.
However, when the environmental conditions are not suitable, such as dry conditions, low temperature and food shortage, for Paramecium sp., sexual reproduction, that is conjugation occurs when environmental conditions are not suitable.

2.2

Living Processes in Unicellular Organisms

Introduction

Unicellular organisms are made up of only one cell.

Amoeba sp.

Amoeba sp. constantly changes its shape when it encounters obstacles.
Amoeba sp. moves by extending out its pseudopodium (false feet) and is followed by the flow of cytoplasm into the extended pseudopodium.
Amoeba sp. responds to stimuli such as chemicals, touch or bright light by moving away from the stimuli.
Amoeba sp. moves towards food by extending its pseudopodium to trap food particles by phagocytosis.
The food vacuole is combined with lysosome.
The food particles are hydrolysed by the enzyme lysozyme in the lysosomes.
The nutrients are absorbed into the cytoplasm.
Undigested food is discharged when the Amoeba sp. moves.
Exchange of oxygen and carbon dioxide gases occur through the plasma membrane by simple diffusion on the surface of the cell.
Ameoba sp. grow by synthesising new cytoplasm.
Waste such as carbon dioxide and ammonia are removed by diffusion.
As Amoeba sp. live in freshwater environments, water will diffuse by osmosis and fill the contractile vacuole.
When the vacuole expands to the maximum size, contraction occurs and water is excreted from time to time.
This process is called osmoregulation.
When the conditions are suitable and there is plenty of food, Amoeba sp. will reproduce via asexual reproduction that is binary fission through mitosis.
However, when the environmental conditions are not suitable, such as dry conditions, low temperature and food shortage, the Amoeba sp. forms spores that will only germinate when the environment improves.

Paramecium sp.

Paramecium sp. moves using rhythmic cilia beats.
Paramecium sp. respond to stimuli such as chemicals, touch or bright light by moving away from the stimuli.
Paramecium sp. the presence of cilium beat helps transfer food particles into the oral groove.
The food vacuole is combined with lysosome.
The food particles are hydrolysed by the enzyme lysozyme in the lysosomes.
The nutrients are absorbed into the cytoplasm.
Undigested food in the Paramecium sp. is discharged through the anus.
Exchange of oxygen and carbon dioxide gases occur through the plasma membrane by simple diffusion on the surface of the cell.
Paramecium sp. grows by synthesising new cytoplasm.
Waste such as carbon dioxide and ammonia are removed by diffusion.
As Paramecium sp. live in freshwater environments, water will diffuse by osmosis and fill the contractile vacuole.
When the vacuole expands to the maximum size, contraction occurs and water is excreted from time to time.
This process is called osmoregulation.
When the conditions are suitable and there is plenty of food, Paramecium sp. will reproduce via asexual reproduction that is binary fission through mitosis.
However, when the environmental conditions are not suitable, such as dry conditions, low temperature and food shortage, for Paramecium sp., sexual reproduction, that is conjugation occurs when environmental conditions are not suitable.