2.1 Simple Tissues

Question 1

Sclerenchyma - brief description

Answer 1

Ground tissue

Dead in maturity

Lacks protoplasm

Elongated, pointed at each end

Cell walls lignified and thickened

Question 2

Sclerenchyma - position in plant.

Answer 2

Fibers - in xylem, phloem, cortex and pericycle of stem and fruit covering.

Gives mechanical support.

Sclerids (stone cells) have very thick cell walls.

In hard part of plant eg. apple core, fruit pulp, act as mechanical support.

Question 3

Collenchyma - brief description

Answer 3

Living cell at maturity.

Thickened walls (cellulose)

Ground tissue.

Question 4

Clooenchyma -rôle in plant and position in plant

Answer 4

Offer support.

Usually found in a region that is actively growing and as part of vascular bundles - eg midrib of leaves or at the point a stem branches.

Question 5

Collenchyma - shape and arrangement.

Answer 5

Elongated with thicker walls than parenchyma.

Arranged in strands

Can be arranged in complete cylinders or separate strands.

Question 6

Parenchyma - function

Answer 6

Primarily food storage.
Large vacuole for food and water storage.
May offer support.
In leaves and stems are photosynthetic (chlorenchyma)
Can be involved in storage of gums, resins, tannins and oils.

Question 7

Parenchyma: description

Answer 7

Ground tissue.
Living cells at maturity
Oval or spherical in shape.
Often have intercellular spaces eg.spongy mesophyll in leaves.

When combined with other cell types they make up more complex tissues.

Question 8

Parenchyma - location in plant

Answer 8

Found in most parts of plant
For example
Vascular tissue
Medullary ray
Cortex pith