Sketch the reproductive parts of a flower.
A flower is modified into complex shoot to carry out sexual reproduction in the higher plants. The terminal or the end part of the axis of the flower that supports all the floral appendages: sepals, petals, stamens and carpels; is known as receptacles. These four whorls of floral appendages attached on the receptacle in which the two lower whorls (calyx and corolla) are sterile; and upper two are (androecium and gynoecium) are fertile or reproductive whorls. The floral parts are explained as below:
1. Calyx: It is the outermost circle of a floral leaves are called calyx and the individual leaf segment is known as sepal, is green in colour. The function of sepals (Or calyx) is to protect the flower in its starting stages when the bud formation occurs.
2. Corolla: This is the second whorl of the floral leaves arise from the inner part to the calyx, and colourful parts of a flower are called corolla and the individual leaf of corolla is known as Petal. The petals lie inside the sepals and are generally coloured which attracts the insects (for pollination) and to protect the reproductive organs of the flower.
3. Androecium: The little stalk and the third whorl of the floral appendage that arises inner to corolla; individual appendage is stamen. Stamen is the male reproductive organ of the plant and consists of two parts: a filament and an anther. The stalk of stamen is called filament and the swollen top of stamen is called anther and it makes the pollen grains and stores them. Pollen grains appear to be yellow, powder like substance to us. Pollen grains contain the male gametes (or male sex cell) of the plant which is present inside a pollen grain is called ‘male nucleus of pollen grain’.
4. Gynoecium (or pistil): In the centre of a flower, there is a flask-shaped organ called pistil and it represents female reproductive organ of the plant. A pistil is constitutes of three parts: stigma, style and ovary. Ovary is the present on the base and is swollen part of the carpel that bears various ovules. Stigma lodges pollen grains. Style is the connection between ovary and stigma.
Classify the changes involved in the following processes as physical or chemical changes:
(a) Photosynthesis
(b) Dissolving sugar in water
(c) Burning of coal
(d) Melting of wax
(e) Beating aluminium to make aluminium foil
(f ) Digestion of food
Given below is a crossword puzzle based on this lesson. Use hints to fill in the blank spaces with letters that complete the words.
Down Across
(D) 1 : Thorough washing (A) 1 : Keeps warm
2 : Animal fibre 2 : Its leaves are eaten by silkworms
3 : Long thread like structure 3 : Hatches from egg of moth
Sketch the cross section of soil and label the various layers.
Here is a crossword puzzle: Good luck!
Across
3. Liquid waste products
4. Solid waste extracted in sewage treatment
6. A word related to hygiene
8. Waste matter discharged from human body
Down
1. Used water
2. A pipe carrying sewage
5. Micro-organisms which causes cholera
7. A chemical to disinfect water
Take three test-tubes. Fill æth of each with water. Label them A, B and C. Keep a snail in test-tube A, a water plant in test-tube B and in C, keep snail and plant both. Which test-tube would have the highest concentration of CO2?
Solve the following crossword puzzle with the clues given:
Across
2. Plantation prevents it.
5. Use should be banned to avoid soil pollution.
6. Type of soil used for making pottery.
7. Living organism in the soil.
Down
1. In desert soil erosion occurs through.
3. Clay and loam are suitable for cereals like.
4. This type of soil can hold very little water.
5. Collective name for layers of soil.
Describe how crystals of copper sulphate are prepared.
Match the items in Column I with those in Column II:
Column I Column II
(i) A home for living organisms (a) Large particles
(ii) Upper layer of the soil (b) All kinds of soil
(iii) Sandy soil (c) Dark in colour
(iv) Middle layer of the soil (d) Small particles and packed tight (v) Clayey soil (e) Lesser amount of humus
Write one similarity and one difference between the nutrition in amoeba and human beings.
When baking soda is mixed with lemon juice, bubbles are formed with the evolution of a gas. What type of change is it? Explain.
Describe the process of neutralisation with the help of an example.
Discuss why wearing more layers of clothing during winter keeps us warmer than wearing just one thick piece of clothing.
Which one of the following place is unlikely to be affected by a cyclone.
(i) Chennai (ii) Mangaluru (Mangalore) (iii) Amritsar (iv) Puri
Blue litmus paper is dipped in a solution. It remains blue. What is the nature of the solution? Explain.
One litre of water at 30°C is mixed with one litre of water at 50°C. The temperature of the mixture will be
(a) 80°C (b) more than 50°C but less than 80°C
(c) 20°C (d) between 30°C and 50°C
What is sewage? Explain why it is harmful to discharge untreated sewage into rivers or seas.
Match the items of Column I with those given in Column II:
Column I Column II
Food components Product(s) of digestion
Carbohydrates Fatty acids and glycerol
Proteins Sugar
Fats Amino acids
Match the following :
(i) Land breeze blows during (a) summer
(ii) Sea breeze blows during (b) winter
(iii) Dark coloured clothes are preferred during (c) day
(iv) Light coloured clothes are preferred during (d) night
Given below is a crossword puzzle based on this lesson. Use hints to fill in the blank spaces with letters that complete the words.
Down Across
(D) 1 : Thorough washing (A) 1 : Keeps warm
2 : Animal fibre 2 : Its leaves are eaten by silkworms
3 : Long thread like structure 3 : Hatches from egg of moth
Classify the changes involved in the following processes as physical or chemical changes:
(a) Photosynthesis
(b) Dissolving sugar in water
(c) Burning of coal
(d) Melting of wax
(e) Beating aluminium to make aluminium foil
(f ) Digestion of food