BIO MODULE 2:Set 6 — Plant Cells, Vacuoles & Chloroplasts

Which structures are listed as present in plant cells but not animal cells?

Cell wall, central vacuole with tonoplast, chloroplasts, and plasmodesmata.

Which structures are listed as present in animal cells but not plant cells?

Lysosomes and centrioles.

What is the main structural component of plant cell walls?

Cellulose fibres.

What is the function of cellulose in plant cell walls?

Providing tensile strength and structural support.

What is a primary cell wall?

A relatively soft and flexible layer of the plant cell wall.

What is a secondary cell wall?

Additional layers of cellulose fibres and carbohydrates deposited inside the primary wall.

What is lignin?

A substance that reinforces secondary cell walls in woody plants.

What is the middle lamella?

A pectin-rich layer that holds the walls of adjacent plant cells together.

What are the main functions of plant cell walls?

Support cells, resist pressure from the central vacuole, and protect against invading bacteria and fungi.

What are plasmodesmata?

Plasma membrane-lined channels connecting the cytoplasm of adjacent plant cells.

What is the function of plasmodesmata?

Allowing ions and small molecules to move directly between neighbouring plant cells.

What is a central vacuole?

A large membrane-bound compartment in plant cells used for storage and other specialized functions.

What percentage of a mature plant cell may be occupied by central vacuoles?

90% or more.

What is the tonoplast?

The membrane surrounding the central vacuole that regulates transport into and out of it.

What substances can central vacuoles store?

Salts, organic acids, sugars, storage proteins, pigments, and waste products.

How do central vacuoles contribute to flower colour?

They store pigments that produce the colours of many flowers.

What are plastids?

Plant cell organelles involved in functions such as photosynthesis and storage.

What is the main function of chloroplasts?

Photosynthesis.

What pigment is found in chloroplasts?

Chlorophyll.

Where are chloroplasts commonly found?

Leaves, other green parts of plants, and algae.

What are thylakoids and grana?

Thylakoids are internal membrane structures in chloroplasts; grana are stacks of thylakoids.

What is the stroma?

The internal fluid of a chloroplast.