Processes of life in unicellular organisms

Unicellular Organisms

Organisms composed of a single cell that can carry out all life processes.

Prokaryotic Cells

Cells without a nucleus, typically unicellular, such as bacteria.

Eukaryotic Cells

Cells with a nucleus, which can be unicellular or multicellular.

Metabolism

The chemical reactions that occur within a cell to maintain life.

Response to Stimuli

The ability of an organism to react to changes in its environment.

Homeostasis

The maintenance of stable internal conditions despite external changes.

Movement

The ability of living organisms to change their position or location.

Growth

The increase in size or number of cells in an organism over time.

Reproduction

The process by which organisms produce offspring, either sexually or asexually.

Excretion

The removal of waste products from metabolic processes.

Nutrition

The intake or production of nutrients necessary for energy and growth.

Heterotrophic Organisms

Organisms that obtain nutrients from their environment.

Autotrophic Organisms

Organisms that produce their own nutrients from inorganic materials.

Paramecium

A genus of unicellular protozoa that are heterotrophic and move using cilia.

Chlamydomonas

A genus of unicellular green algae that are autotrophic and move using flagella.

Cilia

Small hair-like structures that help Paramecium move and respond to stimuli.

Flagella

Whip-like structures that help Chlamydomonas swim and navigate its environment.

Osmoregulation

The process of maintaining water balance within a cell.

Binary Fission

A form of asexual reproduction where a cell divides into two daughter cells.

Growth in Paramecium

As it consumes food, theParamecium enlarges. Once it reaches a certain size it will divide into two daughter cells

Movement in Paramecium

The wave action of the beating cilia helps to propel Parameciumin response to changes in theenvironment, for example, towardswarmer water and away from cooltemperatures

Response to stimuli in Paramecium

Paramecium are able to detect changes in the water temperature around them and move in response to seek warmer temperatures

Homeostasis in both Paramecium and Chlamydomonas

A constant internal environment is maintained by collecting excess water in the contractile vacuoles and then expelling it through the plasma membrane.

Process is called osmoregulation and helps Paramecium and Chlamydomonas to maintain their water balance

Nutrition in paramecium

Paramecium is a heterotroph. It feeds on microorganisms,such as bacteria, algae and yeasts

• It engulfs food particles in vacuoles where digestion takes place

• Soluble products are then absorbed into the cytoplasm of the cell.
  

Reproduction in Paramecium

• It can carry out both sexual and asexual reproduction, though the latter is more common.

• The cell divides into two daughter cells in a process called binary fission (asexual reproduction)

Excretion in paramecium

• Metabolic waste from cytoplasm collects in vacuoles

• vacuole then moves it to the anal pore

• it ruptures, expelling its waste contents into the environment

Some metabolic waste is also removed through the contractile vacuole along with excess water

Metabolism in Paramecium

• Relies on external organic sources for energy and carbon compounds.

• Breaks down nutrients obtained from the environment to sustain life functions.

Metabolism in Chlamydomonas

• Exhibits flexible metabolism, capable of heterotrophic growth using chemical carbon sources like acetate.

• Can grow mixotrophically by utilizing both CO2 and acetate.

Growth in Chlamydomonas

• Increases in size through photosynthesis and the absorption of minerals.

• Divides into two daughter cells once it reaches a certain size.

Movement in Chlamydomonas

• Uses rotating flagella for movement.

• Moves towards areas with higher light intensity for better photosynthesis.

Response to Stimuli in Chlamydomonas

• Senses light changes using its eye spot.

• Moves toward brighter regions to enhance photosynthesis.

Homeostasis in Chlamydomonas

• Maintains water balance via osmoregulation.

• Expels excess water collected in contractile vacuoles.

Nutrition in Chlamydomonas

• Autotrophic; uses chloroplasts to perform photosynthesis.

• Produces its own food.

Reproduction in Chlamydomonas

• Reproduces both sexually and asexually.

• Divides by binary fission or through sexual reproduction when reaching a certain size.

Excretion in Chlamydomonas

• Uses the entire plasma membrane surface to excrete waste products.