CLASSIFICATION OF LIVING THINGS 2

1. Division Bryophyta
2. Division filicinophyta
3. Division coniferophyta
4. Division spermatophyta/angiospermatophyta.

Division Bryophyta

Plants in this division include Mosses and liverworts.

CHARACTERISTICS OF DIVISION BRYOPHYTA

1. They are generally small size, some mosses have only a few cells thick.

2. They have leaf – like thalamus and root – like rhizoids structure but not true leaves or roots.

3. They lack vascular tissues (xylem and phloem).

4. Bryophytes are commonly found in the moist areas such as along the river banks and tress and rocks in humid area.

5. They reproduce both sexually and asexually.

            - They need water during sexual reproduction because the male reproductive cells can only reach the female reproductive cells by swimming.

             - Asexual reproduction is by means of spores.

6. They show alternation of generation. This means that they have two distinct phases in their life cycle.

   The gamete- producing phase called gametophyte stage, Gametes – are male or female reproductive cells.

   The spore producing phase called sporophyte stage.

                                                           MOSSES

Moses consists of a stem- like structure bearing spirally arranged leaf like extensions. They are divided to the substratum by rhizoids.

     
                

The productive parts of mosses plants are the antheridium(male organ) and archegonium. (Female organ)

The antheridium and archegonium can be found on separate plants or on the same plant.

The antheridium releases mobile sperm. The sperm swim in water to reach and fertilize the egg in the archegonium to form a zygote.

The zygote develops into a young sporophyte plant which grows while still attached to the archegonium. It depends on the parent plant for nutrition and support

When it matures the sporophyte forms a capsule which contains spores. When the spores are mature the capsule bursts open and they land produce new mosses plants (gametophytes)

  ADVANTAGE OF MOSSES

1. Mosses help to decompose dead logs.
2. Mosses serve as pioneer plants on bare ground and help to create a suitable environment for the growth and development of other plant.
3. Mosses retain a lot of water. They therefore help to keep the soil moist.
4. When mosses grow in a piece of land, they hold the soil particle together and help to prevent soil erosion.
5. Mosses also provide shelter for insects and other small animals.
6. Some birds and mammals use mosses as nesting materials.
7. Sporangium moss is harvested used in plants nurseries as a plant growing medium.
8. Peat derived from the remains of mosses as an important fuel in Scotland and Ireland.

  DISADVANTAGE OF MOSSES

     1. Mosses occur as weeds in gardens and other places; they are very difficult to get rid of.

     2. Mosses growing around ponds and other small water bodies can grow on the water and cover. It completely causing the area to become marshy

DIVISION FILICINOPHYTA (PTERIDOPHYTA)

This division is made up of ferns. A young fern’s called a fiddle head

     

Characteristics of fern

     1.They are vascular; they have xylem and phloem.

     2. Ferns have leaves (called fronds), stem and root. Frond has small ‘leaflets’ called pinnae singular (pinna) which are connected to rachis. The rachis is the
         middle   part of the frond. It has connected to the rhizome which is the short stem at the basic.

3. The life cycle of fens involves alternation of generations.
4. The sperm swims to the female egg through water. Fertilization produce a zygote (fertilized egg). The zygote grows into a new plant (sporangiosphore) that has leaves a steam and roots.

     5.  The fern plants has spore producing organs called sporangia (singular sporangium) on the underside of the leaves. The sporangia are arranged in compact groups called sori (singular sorus).

                       

     


Sori with spores

When the spore are mature the sporangia releases them into the air. A spore germinate in an environment that is suitable for its development, what germinates is called a prothallus. Prothallus has antheridia and archegonia while produce sperm and egg respectively

      


                                   

Advantages of ferns

1. Many types of ferns are grown as ornament in homes and offices.

2. In some part of the world, the fiddlehead of some types of fern is eaten.

3. In southern Asia, ferns are used as a biological fertilizer. They are able to convert nitrogen from the air into compound that can be used by rice plants.

4. Ferns are major components of coal, a fossil fuel which is made up of the remain of primitive plants

5. Ferns serve as food for various wild animals.


Disadvantage of ferns

 Ferns can be found as weeds in many places. The giant water fern is one the world worst aquatic weeds.
 Ferns dont reproduce with seeds so they dont spread as much as plants that produce seeds.
 

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