Share this:
CLASSIFICATION OF LIVING THINGS
DIVISION CONIFEROPHYTA
Coniferophyta is a division containing cone- bearing plants with needle shaped leaves
The smaller male cones produce a yellowish powder called pollen. It contains the male sex cells of gametes. The large female cone bears small seed like structure called ovules. This contains female gametes.
The male cone is comparable to a flower but consisting only of pollen producing structures. The pollen is formed on the leaf like scales of the cone. The female cone is comparable to a flavor but with ovule forming parts only. The ovules are attached to the leaf scales of the cone
The distinguish features and characteristics of the organism in this Division are
- They are mostly shrubs and trees, with needle shaped leaves
- Their reproductive structures are cones
- The ovules are not enclosed inside an ovary wall
- The dominant generation is the sporophyte
- The majority are evergreen. (they keep their leaves all year round)
- They are widely distributed. (are commonly found in areas with cold climate)
Advantages
- Conifers are relatively fast growing tress
- Are grown in plantations and produce useful timber (softwood)
- They are used extensively in the building industry, paper making and in furniture making
- The trunks of conifers grow very tall and straight. They are often used as telegram poles
DIVISION ANGIOSPERMOPHYTA
(FLOWERING PLANTS)
This division contains wide variety of forms, but all have common distinctive features as you will see
There are two classes of angiosperms
- Monocotyledonae
- Dicotyledonae
The feature of angiosperms is leaves, stem, roots and flowers.
Nearly all angiosperms have the same structure in their feature modified according to type and function
- Sepal: protects the flower parts when it is in bud
- Petals: are often brightly colored to attract insect to pollinate the flower
- Stamen: produce the male gametes
- Carpel: produce the female gametes
- The flower of angiosperms has male structure called stamens. These have a structure called filament support anthers which produce pollen
- The female structures are called carpels. A carpel is compared of stigma, style
and ovary. The ovules are formed inside the ovary. Once a carpel has been pollinated and ovule present successfully fertilized the carpel becomes a fruit and the ovules become seeds.
The Distinguishing features of Angiosperms are
1.Their reproductive structure are flowers
1.Their reproductive structure are flowers
- When anthers and carpels are found in the same flower e.g. Delonix region the flower is said to be bisexual. Some plants produce uni sexual flower (maize produce) produce male flower that can release pollen and female flowers that produce ovules.
2. Ovules are enclosed in an ovary and hence the seeds are enclosed in a fruit.
3. Angiosperms vary greatly in form, size and habitat.
- They can be woody e.g. coconut tree, non- woody (maize plants) some are very small such as groundnut plants while others are very large such as baobab trees
4. They occur in wide range of terrestrial (land) and aquatic (usually fresh water) habitat
Comparing Monocots and Dicots
A bean seed or groundnut seed has 2 cotyledons and is described as dicotyledonous. The maize grain has only one cotyledon and is described as cotyledonous
Examples of monocotyledons are maize, coconut, millet, palms, Grasse and orchids.
Examples of dicotyledons are beans, castor, groundnuts, mango, hibiscus plants and balsam plant.
Definitions
1. MONOCOTYLEDON PLANTS.
– Are plants whose seeds have one seed each. (One cotyledon)
- DICOTYLEDON PLANTS
– Are plants whose seeds have two seeds (two cotyledons)
A. DISTINCTIVE FEATURE OF MONOCOTYLEDONS
1. Their seeds have one cotyledon.
2. The vascular bundles of the stem are scattered
3. The petals are arranged in groups of leaves
4. Leaves have veins running parallel to one another
5. Most have fibrous root system.
B. DISTINCTIVE FEATURE OF DICOTYLEDON
B. DISTINCTIVE FEATURE OF DICOTYLEDON
1. Their seeds have 2 cotyledons.
2. The vascular bundles of the stem and root are arranged regularly
3. The petals are arranged mostly in groups of 5 or more
4. The leaves have veins arranged in a branched network
5. Most have tap root system
Advantage of Angiosperms
Advantage of Angiosperms
1. Are used for timber
2. Are used as a source of charcoal and wood
3. Are used for manufacturing papers
4. Some angiosperms provide medicine (e.g.: neem tree and foxglove)
5. Some flowering plants are used for decorations
6. Angiosperms can be used in production of certain industrial chemicals plastics, rubber, and tannins.
7. Angiosperms can be a good source of organic manure for the production of our crops when they decay.
8. Are used for manufacturing resins.
Disadvantages of Angiosperms
1. Some flowering plants may be allergic to man (e.g. Pollens are allergic to people)
2. The
potted plants in the house compete with man for oxygen
potted plants in the house compete with man for oxygen
3. Some plants are poisonous to man. (E.g. certain type of cassava)
6 Comments