BRASSICA PLANT

IMPORTANCE OF BRASSICA:

• Brassica is used as a food, e.g. leave are used as vegetables.

• From its seeds oil is extracted, which is known as MUSTARD.

PARTS OF BRASSICA PLANT:

Brassica plant is divided on the basis of their functions onto two categories:

• VEGETATIVE PART.

• REPRODUCTIVE PART.

VEGETATIVE PART: 

They are those, which do not take part directly in sexual reproduction.

This part includes:

• Root .

• Stem .

• Leaves.

ROOTS OF BRASSICA: 

• Root is the underground part of the plant, which moves towards the force of gravity.

• It is the first part of the plant, which develops from the RADICLE.

• TAP ROOT SYSTEM is present in brassica plant.

• The first thick root, which arises from the radical, is known as PRIMARY ROOTS.

• It gives of branches, which are known as SECONDARY ROOTS.

• From the secondary roots fine branches comes out, known as TERTIARY ROOTS.

• Tertiary roots have root hairs.

• A cap like structure called ROOT CAP protects the tips of the roots. 

                                    

FUNCTIONS OF ROOTS: 

Root performs various functions:

FIXATION: Root fixes the plant in the soil.

ABSORPTION: The plant absorbs water and mineral salts from the soil through the root hairs only.

CONDUCTION: Root conducts water and mineral salts to the upper part f the plant i.e. stem

STEM OF BRASSICA: 

The stem of brassica is soft and green :

• Stem is present above the ground, and always moves against the force of gravity.

• It is the part of the plant, which develops from PLUMULE.

• The point on the stem which gives rise to the leave is known as NODE.

• The distance between two nodes is INTER-NODE.

FUNCTIONS OF STEM: 

SUPPORT: Stem gives support to the plant body. It gives support to the branches and leaves in such a way that leaves get maximum amount of light for photo synthesis.

CONDUCTION: Stem conducts water and salts from the roots to the upper parts of the plant body. It also transport prepared food from the leaves to the lower parts of plant body.

PRODUCTION: Stem produces branches, leaves and flowers.

LEAVES OF BRASSICA: 

The leaves of brassica is soft and green in color.

•  Leaves arise on the stem from the NODES.

• Its leaves are always parallel to the ground, in order to get maximum light, for the preparation of their food.

• Leaves of brassica are BI-FACIAL(their upper surface differs from the lower surface)

• The upper surface of leaves has less stomata, while the lower surface has less stomata.

PARTS OF LEAVES: 

Brassica leaves has two parts;

i- PETIOLE: It is the lower stalk like part, by which the leaves is attached to the stem.

ii-LAMINA:It is surface of the leaf, which is also known as LEAF BLADE.

• Brassica leaves has WAVY MARGIN.

• In the center of the leaf, a swollen vein known as MID- RIB is present.

• From the mid-rib are made up of VASCULAR TISSUES.

• On the surface of the leaf, waxy layer is present known as CUTICLE.

• The function of cuticle is to prevent extra evaporation of water.

FUNCTION OF LEAF: 

Leaf perform various functions:

SYNTHESIS: Leaves have chlorophyll so they can synthesize their food (glucose) by the process of photosynthesis.

RESPIRATION: Plants take in oxygen and give out carbondioxide through stomata.

EXCRETION: Extra water, carbondioxide and oxygen are taken out through stomata.

REPRODUCTIVE PARTS OF BRASSICA:

FLOWER:

• Flower is the reproductive part of the plant, which is beautiful and attractive. 

• They are yellow in color.

• They are arranged in a special way on the young branches, arrangement is called as INFLORESCENCE.

• Brassica flower is BISEXUAL.

• Flower is attached to the branches with the help of stalk like structure known as PEDICEL/PEDUNCLE.

• The upper portion of the pedicel is flattened and broad, which is known as THALAMUS.

PARTS OF FLOWER:

 There are FOUR parts of flower.

 

CALYX:  

•  It is the outer most part or whorl of the flower.

• It protects the inner part from rain and sun, when the flower is in the BUD.

• It consists of FOUR sepals.

• The sepals are light greenish in young flowers, but as the flower matures they become yellowish, like PETALS.

COROLLA:                                                                                   

• It is the second whorl of the flower.

• It consists of four petals, which are yellow in color.

• The function of corolla is to attract insects, butterflies and bees for cross pollination.

ANDREOCIUM:

• It is the third whorl of the flower.

• This the MALE REPRODUCTIVE part of the plant.

•  It consists of SIX STAMENS, which are arranged in two circles.

• Each stamen consists of two parts.

• The LOWER PART is called as FILAMENT, while the upper swollen part is called as ANTHER.

• In anther the MALE SEX CELLS known as POLLEN GRAINS are produced.

• At the basal portion of the stamens small NECTARIES are present, which produce sweet liquid called NECTAR for insects (food for insects).

GYNOECIUM:

• This is the FOURTH whorl of the flower.

•  It is the FEMALE REPRODUCTIVE part of the flower.

• It consists of TWO CARPELS. Each carpel has three parts

STIGMA(upper swollen part).
 
STYLE (middle stalk like part).  

OVARY (lower swollen part which contains).

• OVULES: EGGS are present in the ovule. 

What is an ALGAE ?

DEFINITION:

“Algae are a large and successful group of organisms, which flourish in the sea and fresh water and in damp places on land”.  

OCCURRENCE: 

  Algae are present in fresh and sea water, so that they are aquatic plant. Algae growth in a       natural occurrence in all water bodies. 

 

STRUCTURE:

•  Algae have very simple structure and do not have stem or root.

• Their body is like filament or ribbon shaped.

•  Most algae contain green chlorophyll, and can produce foods, such as sugars, from the sun.

• They may be branched or unbranched.

                              

NUTRITION:

They are AUTOTROPHS and prepare their own food with the help of chlorophyll and sun light.

REPRODUCTION:

Algae reproduce asexually by FRAGMENTAION.(process of breaking down into smaller equal parts or fragments)

TYPES OF ALGAE: There are about 20 thousand types of algae, depending upon their colored pigments and structures.

The different types of alga on the basis of colored pigments are: 

•  Blue Algae.

• Green Algae.

• Red Algae.

• Brown Algae.

• Golden Algae.

•  Blue-Green Algae.

ADVANTAGES/USES/IMPORTANCE OF ALGAE:

•  Algae are used as food for aquatic plants.

• They are used in the preparation of tooth paste and tooth powders.

• Several marine algae are important source of many commercial materials.

• Some antiseptics, such as tincture, iodine are also obtained from many algae.

• Many of the sea beads are used as human foods, rich in carbohydrates and vitamins.

•  Some algae are used as fertilizers and for cleaning household utensils.

HARMFUL ASPECTS/DISADVANTAGES OF ALGAE:

• Algae spoil the taste of drinking water and give it a bad odor.

• Some algae produce toxic material in water, which produces diseases in fishes, humans and others.

• Algae growing in mountains, pools and falls of recreational sights spoil their beauty.

MUSHROOMS:

What is a MUSHROOM?

“Mushrooms are multicellular fungi and they blogs to the group of fungi called as BASIDIOMYCETES”.  
 
HABITAT -   Living Place

They prefer hot and humid climate and spread underground in the soil that contains dead organic matter. They commonly appear on the waste product and also on the dumps of debris during rainy season   

 
 

Structure:
They are umbrella like.Their body consists of mycelium, stalk, gills bearing pores and cap.

Size:They are 3 to 4 inches in size.  

Fruit Body:Fruit body consists of the stalk,a cap shape pileus,many gills plates and many hyphae of mycelium. 

NUTRITION:They are seprophytes, as they obtain their food from decomposed dead bodies of other organisms.

TYPES OF MUSHROOMS:

Some of the mushrooms like AGARICUS can be used as food. Some mushrooms called TOAD-STOOL is poisonous and not eatable, if eaten a person may die.