Cells Flashcards
(28 cards)
What is a unicellular (acellular) organism?
An organism with only one cell.
Why do unicellular organisms have to be microscopic?
Food and waste products must be able to leave all parts of the cell quickly. If the cell was large, the food would find it difficult to diffuse quickly into the deepest part of the cell. Similarly, it would take too long for waste products to work their way out which would harm the cell.
Name 4 examples of unicellular organisms.
Bacteria.
Amoeba.
Paramecium.
Euglena.
Where can you find amoeba?
Ponds and moist ground.
What is the nucleus?
Controls all of the cell’s movement.
What is the cell membrane?
This holds the cell together and controls what comes in and out of the cell such as food and waste.
What is a pseudopod?
These cytoplasmic extensions allow the amoeba to move around and engulf food.
What is the cytoplasm?
This is a jelly like substance. Chemical reactions occur here such as aerobic respiration.
What is a food vacuole?
These are small bags that encloses food in the amoeba. Enzymes then enter the vacuole to digest the food.
How do amoebas move?
Locomotion. They move by changing the shape of their pseudopods.
How do amoebas eat?
Surround bits of food with pseudopods that form around the food; the amoeba incorporates the food into the cell.
How do amoebas reproduce?
Asexually. This means that the parent cell divides in a process called fission and produces two smaller copies of itself.
What are cilia?
Hair like structures that act like microscopic oars to push through the water, enabling the cell to swim.
What is the oral groove?
Food is swept into this groove where it is digested.
What is the function of the micronucleus?
This holds information that the Paramecium will only use once or twice in its life. e.g. Reproduction.
What is the macronucleus?
This holds all the information that the cell would need everyday. e.g. Respiration, movement etc.
What are multicellular organisms?
Organisms made up of more than once cell.
What is a simple multicellular organism?
An organism made up of a chain of similar cells working together.
Name an example of a simple multicellular organism.
Algae
Where can algae be found?
Ponds and rock pools.
What are complex multicellular organisms?
Organisms made up of many different types of cells working together. Complex multicellular organisms can have specialisation. This means that the same types of cell can be grouped together to do the same job. These groups are called tissues.
Name an example of a complex multicellular organism.
Humans
What is an organ.
Sometimes, different tissues can work together to do the same job. This is an organ.
What are animal cells made up of?
Cell Membrane.
Cytoplasm.
Nucleus.
