Variety of living organisms

Question 1

What are the two kinds of organisms broadly?

Answer 1

Eukaryotic organisms

Prokaryotic organisms

Question 2

What are Eukaryotic organisms?

Answer 2

Eukaryotes are organisms that have a membrane-bound nucleus and organelles inside their cells.
They can be unicellular (only one cell) or multicellular (more than one cell).

Question 3

What are the 5 different kingdoms of organisms?

Answer 3

Plants
Animals
Fungi
Bacteria
Protoctist

Question 4

What are the characteristics of Plants?

Answer 4

Eg: herbaceous legumes (peas), cereals (wheat)
Multicellular
Cells contain a nucleus, chloroplasts, and cellulose cell walls
All feed by photosynthesis
Store carbohydrates as starch or sucrose
Contain a large, central cell vacuole

Question 5

What are the characteristics of Animals?

Answer 5

Eg: humans (mammals), butterflies (insects)
Multicellular
Cells contain a nucleus but no cell walls or chloroplasts
Feed on organic substances made by other living things
Store carbohydrates as glycogen

Question 6

What are the characteristics of Fungi?

Answer 6

E.g. molds, mushrooms, yeast
Most are multicellular with a mycelium of thread-like structures called hyphae which have many nuclei but some are single-celled (eg yeast is single-celled)
Cells have nuclei and cell walls made from chitin
Feed by saprotrophic (on dead or decaying material) or parasitic (on live material) nutrition by secreting extracellular enzymes onto the food
May store carbohydrates as glycogen

Question 7

What are the characteristics of Protoctists?

Answer 7

E.g. Amoeba (like an animal), Chlorella (like a plant)
Most are unicellular
All have a nucleus; some may have cell walls and chloroplasts, meaning some protoctists photosynthesize like plants, and some feed on organic substances made by other living things like animals

Question 8

What are Prokaryotic organisms?

Answer 8

Prokaryotes do not have a membrane-bound nucleus or membrane-bound organelles inside their cells.

Question 9

What are the characteristics of Bacteria?

Answer 9

E.g. bacteria (Lactobacillus d. bulgaricus (rod-shaped bacterium used in yogurt production), Pneumococcus (spherical bacterium that causes pneumonia).
Unicellular and microscopic.
Have a cell wall, cell membrane, cytoplasm, and plasmids.
Some can carry out photosynthesis but they mainly feed off other organisms, either dead or alive.

Question 10

What are pathogens?

Answer 10

An organism that causes disease

Fungi, protoctists, bacteria, and viruses can all be pathogens

Question 11

What are the characteristics of viruses?

Answer 11

E.g. Tobacco Mosaic Virus, Influenza virus
Much smaller than bacteria
They are not made from cells and are not considered living organisms as they do not carry out all the life processes
Parasitic – reproduce inside host cells by hijacking the cell’s mechanisms to make multiple copies and then bursts out of the cell to spread throughout the host
Able to infect every type of living cell
The envelope is used to gain entry into host cells
The capsid is a protein coat used to protect the genetic information
The DNA or RNA contains the code for building new viruses.