4.2 Levels of Organisation in Multicellular Organisms

Question 1

List the 4 levels of organisation in multicellular organisms and give an example for each:

Answer 1

• Specialised cells (Eg. Muscle cell)
• Tissues (Eg. Muscle tissue)
• Organs (Eg. Heart)
• Systems (Eg. Circulatory system)

Question 2

What is a specialised cell? Give an example:

Answer 2

Have specific function and have unique structural adaptions that enable them to carry out these functions.
-Are the building blocks of complex tissues and organs
Eg. Guard cells in plants and muscle cells in animals

Question 3

What are tissues?

Answer 3

Groups of specialised cells working together to carry out a particular function.

Question 4

What are organs? Give an example:

Answer 4

Two or more tissues that work together to perform one or more specialised tasks.
Eg. Leaves and roots in plants, and the heart, liver, and brain in mammals

Question 5

What are systems?

Answer 5

Organs working together.

Eg. The respiratory system

Question 6

What are organisms? Give an example:

Answer 6

The final level in the organisms itself with systems working together.

Question 7

What are simple multicellular organisms? Give an example:

Answer 7

Are only a few cells thick and do not have tissues or organs. Materials can diffuse easily into and between cells.
-Eg. Sponges, cnidarians

Question 8

What are non-vascular plants? Give an example:

Answer 8

Have only simplified tissues and limited size due to the lack of structural support.
Eg. Algae and mosses such as liverwort, hornwort, moss.

Question 9

What are vascular tissues?

Answer 9

Are organised into tissues, organs, and systems, and Contain the vascular tissues xylem (water) and phloem (food/glucose).

Question 10

Describe the 5 major organs in vascular plants:

Answer 10

• Roots which absorb and store water and nutrients
• Leaves (photosynthesis)
• Stems (support)
• Flowers (reproductive)
• Fruit (protection and dispersal of seeds)

Question 11

Describe the 3 basic types of tissue in vertebrates:

Answer 11

• Muscle tissue: Cells that can contract
• Nerve tissue: Neurons essential for communication and coordination
• Epithelial tissues: One or more layers of cell that cover most internal and external surfaces

Question 12

Give some examples of organs in complex animals:

Answer 12

• The eye
• Skin
• Heart