Tissues

Question 1

All tissues that are
neither dermal nor vascular in plants :

Answer 1

Ground Tissue.

Question 2

Tell all components and function of Dermal tissue:

Answer 2

Components :
- Epidermis
- Periderm

Function:
- Protection
- Prevent Loss of Water

Question 3

Tell all components and function of Ground tissue:

Answer 3

Components:
- Parenchyma
- Collenchyma
- Sclerenchyma

Functions:
- Metabolism
- Storage
- Support

Question 4

Tell all components and function of Vascular tissue:

Answer 4

Components:
- Xylem
- Phloem

Function:
- Transport

Question 5

Parenchyma, Collenchyma, and Sclerenchyma are…

Answer 5

Simple tissue

Question 6

Xylem, Phloem, Epidermis, Peridermis, and Secretory Cells and
Tissues are…

Answer 6

Complex tissue

Question 7

Parenchyma

Answer 7

• Most abundant tissue find in plants.
  -have large vacuoles
• may contain: Starch grains, Oils, Tannins, Crystals, and Other secretions.
  -Mostly found in aquatic and wetland plants.
  -Parenchyma cells have spaces between
  them.

Question 8

Parenchyma tissue with extensive connected air spaces is referred to as…

Answer 8

Aerenchyma
(give plant ability and stability to float)

Question 9

Parenchyma cells containing numerous chloroplasts and tissues functioning mainly in photosynthesis:

Answer 9

Chlorenchyma

Question 10

Chlorenchyma vs. Aerenchyma

Answer 10

Chlorenchyma –> lot of chloroplast

Aerenchyma –> lot of air cavity

Question 11

What parenchyma is capable of:

Answer 11

• Mature parenchyma cells can divide long after they were produced by a meristem. Parenchyma cells live a long time.
• When a cutting (segment of stem) is induced to grow, parenchyma cells start dividing and give rise to new roots.
• Capacity of Parenchyma cells to multiply is important in repair of tissues.

Question 12

Collenchyma cells :

Answer 12

• Have living cytoplasm
  and may remain alive a long time.
• Generally thicker walls and more uneven in thickness than those of
  parenchyma cells. Unevenness due to extra primary wall in corners.
• Often occur just beneath
  the epidermi.
• flexible support for growing organs and mature organs.

Question 13

Sclerenchyma tissue :

Answer 13

• Cells have thick, tough,
  secondary walls, normally
  impregnated with lignin.
  _ Cells are dead at maturity and function in support
• Two forms of sclerenchyma occur :
• Sclereids
• Fibers

Question 14

Are the reduced form of
sclerenchyma cells with highly thickened, lignified walls. May be randomly distributed in other tissues….

Answer 14

Sclereids (stone cells)

Question 15

May be found in association with
different tissues in roots, stems, leaves, and fruits.
They are usually much longer than wide and have a proportionately tiny cavity, or lumen,
in the center of the cell…

Answer 15

Fibers

Question 16

Main transport
systems of plants. Typically occur together in vascular bundles in all plant organs.

Answer 16

Xylem and Phloem

Question 17

Xylem

Answer 17

• Transports water and minerals absorbed by the roots throughout
  all organs.
• Consists of a combination of:
• Parenchyma cells
• Fibers
• Vessels
• Tracheids
• Ray cells

Question 18

Vessels

Answer 18

• Have thick secondary
  cell walls and are open at their ends.
• Stacked end-on-end to form long tubes.
• Perforation plate with bars or holes may be found between the end walls of each pair of vessels elements.

Question 19

• Found in Vessels
• Flow of fluid through the vessels is not blocked by it.
• But may block the
  movement of objects, such as fungal spores that may invade the xylem.

What is it ?

Answer 19

Perforation Plates

Question 20

Tracheids

Answer 20

• Dead at maturity and have thick secondary cell walls.
• Ends overlapping with those of other tracheids.
• Usually, pairs of pits are present wherever two
  tracheids are in contact with one another.
• Pits allow water to pass from cell to cell.

Question 21

Ray Cells

Answer 21

• Lateral conduction takes place in the rays.
• Long-lived parenchyma cells produced in horizontal rows by
  special ray initials of the vascular cambium
• Function in food storage

Question 22

Phloem

Answer 22

• Phloem tissue conducts dissolved food materials (primarily sugars) PS throughout the plant.
• Composed mostly of 2 types of cells without secondary walls : Sieve tube members (relatively large and cylindrical) and Companion cells(narrower)
• Includes fibers, parenchyma, and ray cells
• End walls full of small pores (sieve plates) through which the cytoplasm extends
  from cell to cell.

Question 23

Sieve tubes members

Answer 23

• No nuclei at maturity
• Cytoplasm very active in conduction of food materials.
• Laid end to end in Phloem.

Question 24

Companion cells

Answer 24

• Found in Phloem
• Form a close relationship with the sieve tubes and aid in the conduction of the food.

Question 25

Sieve cells

Answer 25

- Similar to sieve tube members but tend to overlap at their ends rather than form continuous tubes - Found in ferns and cone-bearing trees - Have no nuclei at maturity and no adjacent companion cells - Have adjacent albuminous cells (Equivalent to companion cells)

Question 26

Dermal Tissues

Answer 26

- Meristematic tissues - The outer layer of tissue surrounding the entire plant, covers and protects the plant, and controls gas exchange and water absorption.

Question 27

Epidermis

Answer 27

- The outermost layer of cells of all young plant organs. - Since it is in direct contact with the environment, it is subject to modification by the environment and often includes several different kinds of cells. - one cell thick

Question 28

Vallen roots

Answer 28

- Few plants produce aerial roots called velamen roots. - The epidermis may be several cells thick, with the outer cells functioning something like a sponge.

Question 29

Cutin

Answer 29

- Fatty substance within and on the outer walls - Forms a protective layer called the cuticle - The epidermis secrets a wax on top of the cuticle - Prevents water loss - Protects from bacteria and other disease organisms

Question 30

They are ubular extensions of roots formed by epidermal cells. They greatly increase the absorptive area of the surface. Some of different nature occur on the epidermis (Trichomes) of above-ground parts of plants. What are they ?

Answer 30

Root Hairs

Question 31

The stomata are bordered by pairs of specialized epidermal cells called... Differ in shape from other epidermal cells Contain chloroplasts.

Answer 31

Guard Cells

Question 32

Other epidermal cells

Answer 32

- Glands that secrete protective or other substances - Hairs that either reduce water loss or repel insects and animals

Question 33

Periderm

Answer 33

- In woody plants, the epidermis is sloughed off and replaced by a periderm after the cork cambium begins producing new tissues that increase the girth of the stem or root. - Constitutes the outer bark, primarily composed of somewhat rectangular and boxlike cork cells, which are dead at maturity. - While the cytoplasm of cork cells is functioning, it secretes a fatty substance, suberin, into the walls. - Makes cork cells waterproof and helps them protect the phloem and other tissues beneath the bark from: * Drying out * Mechanical injury * Freezing temperatures

Question 34

Lenticels

Answer 34

- Loosely arranged parenchyma cells that are not impregnated with suberin. - Function in gas exchange between the air and the interior of the stem.

Question 35

Secretory Cells and Tissues

Answer 35

- Cells or tissues often derived from parenchyma, can occur in various places in a plant. - Common secretory tissues include those that secrete: - Nectar in flowers; - Oils in citrus, mint, and other leaves; - Mucilage in the glandular hairs of sundews and other insect-trapping plants - Latex in members of several plant families, such as the Spurge Family - Resins in coniferous plants, such as pine trees