M2.1

Question 1

Unicellular organism definition

Answer 1

• A single cell performs all seven functions
• A complete living organism by itself, does not depend on other cells for survival
• E.g. streptococcus, amoeba

Question 1

Signs of life

Answer 1

MRS GREN:
- Movement
- Respiration
- Sensitivity
- Growth
- Reproduction
- Excretion
- Nutrition

Question 2

Multicellular organism definition

Answer 2

• Consists of millions of specialised cells that communicate with each other to perform different functions in the body

Question 3

Colonial organism

Answer 3

• Made up of unicellular or multicellular organisms living together, e.g. Volvox colony (unicellular), sponges (multicellular)
• In a unicellular colony, each organism can survive on its own but prefer to live together as this increases their chances of survival
• In a multicellular colony, individuals cannot survive outside the colony and depend on one another for survival (e.g. portugese-man-o-war, a zooid)

Question 4

Colonial vs Multicellular organisms

Answer 4

Colonial organisms cells NOT specialised

Multicellular organisms have SPECIALISED Cells