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.
Match items in Column I with those in Column II:
Column I Column II
(a) Bud (i) Maple
(b) Eyes (ii) Spirogyra
(c) Fragmentation (iii) Yeast
(d) Wings (iv) Bread mould
(e) Spores (v) Potato
(vi) Rose
Describe the various ways by which seeds are dispersed.
How does the process of fertilisation take place in flowers?
Describe the different methods of asexual reproduction. Give examples.
Explain the difference between self-pollination and cross-pollination.
Explain what you understand by sexual reproduction.
State the main difference between asexual and sexual reproduction.
Tick the correct answer:
(a) The reproductive part of a plant is the
(i) leaf (ii) stem (iii) root (iv) flower
(b) The process of fusion of the male and the female gametes is called
(i) fertilisation (ii) pollination
(iii) reproduction (iv) seed formation
(c) Mature ovary forms the
(i) seed (ii) stamen
(iii) pistil (iv) fruit
(d) A spore producing plant is
(i) rose (ii) bread mould
(iii) potato (iv) ginger
(e) Bryophyllum can reproduce by its
(i) stem (ii) leaves
(iii) roots (iv) flower
Fill in the blanks:
(a) Production of new individuals from the vegetative part of parent is called_____________.
(b) A flower may have either male or female reproductive parts. Such a flower is called_____________.
(c) The transfer of pollen grains from the anther to the stigma of the same or of another flower of the same kind is known as _____________.
(d) The fusion of male and female gametes is termed as _____________.
(e) Seed dispersal takes place by means of _____________, _____________ and _____________.
State similarities and differences between the laboratory thermometer and the clinical thermometer.
State differences between acids and bases.
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
Name the elements that determine the weather of a place.
Fill the missing word in the blank spaces in the following statements:
(a) Wind is——————air.
(b) Winds are generated due to —————— heating on the earth.
(c) Near the earth’s surface __________air rises up whereas ___________ air comes down.
(d) Air moves from a region of ——— pressure to a region of ———.
In addition to the rock particles, the soil contains
(i) air and water
(ii) water and plants
(iii) minerals, organic matter, air and water
(iv) water, air and plants
Why does an athlete breathe faster and deeper than usual after finishing the race?
Match structures given in Column I with functions given in Column II.
Column I Column II
(i) Stomata (a) Absorption of water
(ii) Xylem (b) Transpiration
(iii) Root hairs (c) Transport of food
(iv) Phloem (d) Transport of water
(e) Synthesis of carbohydrates
Classify the following as motion along a straight line, circular or oscillatory motion:
(i) Motion of your hands while running.
(ii) Motion of a horse pulling a cart on a straight road.
(iii) Motion of a child in a merry-go-round.
(iv) Motion of a child on a see-saw.
(v) Motion of the hammer of an electric bell.
(vi) Motion of a train on a straight bridge.
Why do organisms need to take food?
What is sludge? Explain how it is treated.
Match the items given in Column I with one or more items of Column II.
Column I Column II
(a) A plane mirror (i) Used as a magnifying glass.
(b) A convex mirror (ii) Can form image of objects spread over a large area.
(c) A convex lens (iii) Used by dentists to see enlarged image of teeth.
(d) A concave mirror (iv) The image is always inverted and magnified. (e) A concave lens (v) The image is erect and of the same size as the object.
(vi) The image is erect and smaller in size than the object.
State two differences between a convex and a concave lens.
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
An iron ball at 40°C is dropped in a mug containing water at 40°C. The heat will
(a) flow from iron ball to water.
(b) not flow from iron ball to water or from water to iron ball.
(c) flow from water to iron ball.
(d) increase the temperature of both.
What is a virtual image? Give one situation where a virtual image is formed.
Explain how forests prevent floods.
Which of the following statements is not correct?
(i) Forests protect the soil from erosion.
(ii) Plants and animals in a forest are not depedent on one another.
(iii) Forests influence the climate and water cycle.
(iv) Soil helps forests to grow and regenerate
Describe the function of the heart.
Suppose the two photographs, shown in Fig. 13.1 and Fig. 13.2, had been taken at an interval of 10 seconds. If a distance of 100 metres is shown by 1 cm in these photographs, calculate the speed of the blue car.