3.2 - Eukaryotic cell structure: Plant, Algal and Fungal cells

Question 1

Fungal cells (what do they not contain and difference in one of its structures compared to plants):

Answer 1

• Contain most of the organelles found in plant cells.
• Do not contain chloroplasts.
• Contain cell walls made up of chitin rather than cellulose.

Question 2

Algal cells (organelle comparison with plants and chloroplast difference):

Answer 2

• Contain the same organelles as plant cells.
• Contain chloroplasts with different shapes to those found in plant cells.

Question 3

Vacuole (2S and 1F):

Answer 3

Structure:

• Contains cell sap (solution of salts and sugars, among other substances).
• Surrounded by a selectively permeable membrane known as a tonoplast.

Function:

• Helps to maintain pressure within the cell, which keeps the cell rigid and stops the plant from wilting.

Question 4

Chloroplasts (3S and 1F):

Answer 4

Structure:

• Contain fluid-filled sacs known as thylakoids which are stacked up to form grana.
• Surrounded by a double membrane, enclosing a fluid known as stroma.
• Contain their own DNA and ribosomes.

Function:

• Site of photosynthesis- These reactions take place in the grana and stroma.

Question 5

Cell Wall Structure (2S and 3F):

Answer 5

Structure:

• Made up of cellulose.
• Contains channels (gaps) known as plasmodesmata (or plasmodesma if just one).

Functions:

• Supports the cell- Contents of the cell press against the cell wall to make it rigid.
• Prevents the cell from bursting- The cell wall can withstand high osmotic pressure.
• Allows exchange of substances between cells - Plasmodesmata connects neighbouring cells.