KINGDOM PLANTAE

This kingdom consists of all plants.

Importance of plants

  1. Plants act as a habitat for many living organisms.
  2. Animals feed on plants.
  3. Trees breathe out oxygen which is needed by animals and they carry out photosynthesisand use oxygen.
  4. Forests help in rainfall formation.
  5. They also act as a habitat for many animals

Characteristics of plants

  1. Their cells are surrounded by cellulose cell walls which give the cells a definite shape.
  2. They have chlorophyllwhich is used for photosynthesis.
  3. They have two main parts, that is, the shoot system and root systems.
  4. They reproduce by means of flowers, that is, the reproductive part is a flower.

DIVISIONS OF KINGDOM PLANTAE

  1. Phycophyta (Algae)
  2. Bryophyta (Moses and liver warts)
  3. Pteridaphyta (Ferns)
  4. Spermataphyta (seed bearing plants)

DIVISION PHYCOPHYTA(Algae)

EXAMPLES:

  1. Sea weed
  2. Fucus (brown algae)
  3. Pond weeds

Characteristics of Phycophyta

  1. Nearly all are aquatic; some grow in damp soil.
  2. Do not have roots, stems, leaves or specialized conducting systems.
  3. Some are unicellular, others are filamentous and some have flat bodies called a “thallus.”
  4. All have chlorophyll but in many, other pigments are also present which mask the green color.
  5. Are flowerless plants.
  6. Reproduction is by asexual and sexual means.

DIAGRAM SHOWINGA SPIROGYRA(A FILAMENTOUS ALGAE)

ECONOMIC IMPORTANCEOF ALGAE /PHYCO PHYTA

  1. They produce oxygen needed for aquatic life and uptake of carbon dioxide.
  2. Food source and energy for animals.
  3. Used in preparation of soap, gelatin and other food e.g. Ice cream.
  4. Cause eutrophication of water bodies.

DIVISION: BRYOPHYTA.

Examples: Mosses

: Liver warts

Characteristics:

  1. Are flowerless plants
  2. Grow in moist places (are terrestrial)
  3. No roots but anchored by root-like structures called rhizoids.
  4. Tiny plants, green in color.
  5. Have no vascular tissue.
  6. Reproduce asexually by means of spores and sexually by means of gamete formation life cycle, thatis, undergo alternation of generation.

ECONOMIC IMPORTANCE

  1. Colonize bare land, promoting the growth of other plant species.
  2. Prevent soil erosion.
  3. Form fertile soil used by nursery men for packing roots of garden plants.

Labeled diagram of a moss

DIVISION: PTERIDOPHYTA.

Examples:

club mosses

horse tails

ferns

wood ferns

aquatic ferns

Characteristics:

  1. They are flowerless plants.
  2. They are large plants which are green in color.
  3. They are mainly terrestrial though others grow in water.
  4. Have vascular tissue consisting of xylem and phloem.
  5. Have well developed roots, stems and leaves.
  6. Reproduce by means of spores / asexually and sexually.
  7. Stems of ferns are thick and grow horizontally under the ground. Has stems known as rhizomes.
  8. Have adventitious roots growing from the rhizomes of the plants.
  9. Have large compound leaves known as fronds.

DIAGRAM SHOWING A FERN


DIVISION :SPERMATOPHYTA.

Comes from: spermae -meaning seed

Phyta - meaning plants

EXAMPLES:

  • Maize
  • Mango
  • Orange
  • Hibiscus
  • Beans

Characteristics:

  1. They are terrestrial.
  2. They have chlorophyll.
  3. Have well developed roots, stems and leaves.
  4. Reproduce both asexually and sexually.
  5. They form seeds after fertilization.
  6. Have vascular tissues, that is, xylem and phloem.

Spermatophyta is divided into two classes –namely:

  1. Class: Gymnospermae.
  2. Class: Angiospermae.

CLASS GYMNOSPERMAE (Cone bearing plants)

Comes from:- gymno-naked

spermae-seeds

They are also referred to as conifers.

Examples:

- Pines

-cypress

-fir

Characteristics:

  1. Do not produce flowers.
  2. Have needle-like leaves.
  3. Seeds develop on cones.
  4. Xylem consists of only tracheids.
  5. Have ovules but without ovary hence posses naked seeds and no fruits.
  6. All are woody plants and most of them are fruits.
  7. Most common in temperate climate.

CLASS ANGIOSPERMAE(Flower bearing plants)

Comes from: - angio – enclosed

spermae –seeds

Examples: -Hibiscus

-Beans

-Maize

-Grasses.

Characteristics:

  1. Bear flowers as their reproductive part.
  2. Produce seeds enclosed in ovaries.
  3. Form fruits which develop from the ovary.
  4. Are terrestrial plants.
  5. Have xylem made of both trachied and vessels.

Angiospermae is subdivided into sub classes which are:

  1. Monocotyledonae(seeds with one cotyledon)
  2. Diocotyledonae(seeds with two cotyledons)

MONOCOTYLEDONAE

Examples:

-maize

-rice

-sorghum

-millet

-Wheat.

Characteristics:

  1. Have fibrous roots.
  2. Have parallel veined leaves.
  3. Seeds have on cotyledon.
  4. Do not undergo secondary growth.
  5. Posses numerous but scattered vascular bundles.

DICOTYLEDONAE

Examples:-Beans, peas, groundnuts, Soya beans.

Characteristics:

  1. Have tap root system.
  2. Have network veined leaves.
  3. Have two cotyledons.
  4. Posses arranged vascular bundles which form a ring.
  5. Undergo secondary growth.

Difference between dicotyledonae and monocotyledonae

dicotyledonae / monocotyledonae
Have tap root system. / Have fibrous root system.
Leaves have network venation. / Leaves have parallel venation.
Have two cotyledons. / Have one cotyledon.
Posses arranged vascular bundles. / Posses scattered vascular bundles.
Undergo secondary growth. / Do not undergo secondary growth.

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