Science 1 Marks Question

Gamete is the odd-one out as it is responsible for sexual reproduction while the remaining three are methods of asexual reproduction.

Reproduction is essential for continuation of the species from generation to generation.

The ability of living things to repair themselves or grow lost parts is called regeneration.

Hooks and spines help seeds and fruits to stick to the bodies of animals and be safely dispersed or transported to far off places.

Spores are covered by a hard covering to provide protection from harsh conditions.

The transfer of pollen grains of a flower to the stigma of same flower or that of a different flower of the same kind is called pollination.

If the filament of Spirogyra are broken into fragments, then each fragment will develop into a new plant.

Asexually by vegetative propagation.

By pollinating agents like wind, water and animals.

Roots that store food are known as tubers.

By the means of spores.

A node is a part of the stem from where a leaf grows.

The process of reproduction is necessary for the perpetuation and preservation of species and to increase the number of members of species.

A flower may have either male or female reproductive parts. Such a flower is called unisexual flowers.

Tubers.

Algae reproduce by a method known as fragmentation. The breaking down of filaments into fragments that grow into young ones is called fragmentation.

Pollen.

Seed dispersal takes place by means of wind, water and animals.

Mould is a type of fungus that grows on moist organic surfaces like leather shoes and moist walls.

Spores are produced by fungi, ferns and mosses during unfavourable conditions.

The fusion of male and female gametes is termed as fertilisation.

Fusion of the male and female gametes is called fertilization.

Flower.

This is done to avoid overcrowding and to avoid scarcity of nutrients, light, air and space for the seeds.

Moss and ferns.

Flowers are so colourful because they absorb and reflect light energy. Fragrance results from production of volatile chemicals which evaporate.

The male reproductive part is stamen and the female reproductive part is pistil.

Zygote is a product formed by the fusion of the male and female gametes.

Production of new individuals from the vegetative part of parent is called vegetative propagation.

Oscillatory motion.

The given figure shows self-pollination, as the pollen grains from anther of flower are transferred to the stigma of same flower.

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 pollination.

A flower may have either male or female reproductive parts. Such a flower is called unisexual.

Grafting is an artificial method of vegetative propagation in which the desired plant is obtained from two different individual plants called stock (root portion from one plant) and Scion (stem portion from another plant).

Binary fission.

Circular motion.

The breaking of the body into two or more parts is called fragmentation. It can be seen in Spirogyra.

The anther of flower contains pollen sacs that produce Pollen grains.

Asexual and sexual.

1. Wind.
2. Water.
3. Man and animals, birds, bats, squirrels.

Root, stem and leaves.

After fertilisation, the ovary of a flower develops and becomes a fruit with seeds present inside.

Unisexual flower can self-pollinate where both male and female flowers are present on the same plant. The stigma of the female flower can be pollinated by the pollen of the male flower present on the same plant.

A stamen consists of anther and filament.

During wind pollination many pollen grains are lost. So to ensure that at least some pollens reach the stigma, a large number of pollen grains are produced.

The four main parts of a flower are:

1. Sepals.
2. Petals.
3. Stamen.
4. Pistil.

Budding.

Coconut.

Straight line motion.

Pollen grains.

Ovary is the part where male and female gametes fuse together.

Tissue culture is an artificial method of vegetative propagation in which tissue from the plant tip is grown in an artificial nutrient medium to produce callus which can produce new plants.

Mustard and rose.

Binary fission is the odd-one out as it a method of asexual reproduction while the rest three are artificial methods of vegetative propagation.

There are different methods by which plants reproduce asexually. They are vegetative propagation, budding, fragmentation and spore formation.

Vegetative propagation is defined as the production of a new individual from a body part like leaves, stems and roots.

Carpel.

Xanthium and Urena.

Reproduction is the process of production of new similar organisms from their parents.

Male reproductive part.

Flowers are generally attract insects and other living organisms for pollination.

Oscillatory motion.

Cucumber, maize and watermelon.

The bulb-like projections formed during reproduction are called buds.

Fungi, ferns and mosses reproduce by spore formation.

The fusion of male nucleus (male gamete) with that of egg cell (female gamete) is known as fertilisation.

If seeds are not able to disperse, they will clutter on one place and would not be able to grow properly because of lack of nutrients.

To avoid growing of the plants at one place leading to scarcity of nutrients and ensure survival of the plants, seeds are dispersed.

Banana forms from one parent only. There is no seed production.

Straigght line motion.

Vallisneria and Hydrilla.

The three agents of pollination are:

1. Insect.
2. Wind.
3. Water.

Mulberry.

Pollen grains have a tough protective coat which presents them from drying up.

Insect pollinated flowers are brightly coloured and sweet smelling to attract insects to itself.

The two ways in which pollination may occur in plants are:

1. Self-pollination.
2. Cross-pollination.

Buds are small bulb-like projections of yeast cell. These are asexual reproducing bodies of yeast.

In sexual reproduction, the male and the female gametes fuse to form seeds that eventually develop into new plants.

A carpel consists of the ovary, style and stigma.

1. Spirogyra – fragmentation.
2. Yeast – budding.
3. Money plant – Vegetative propagation.

Zygote.

Dispersal is the scattering of seeds to far away places. The agents of dispersal are wind, water, insects and animals.

Sweet potato and dahlia develops new plants through their roots by the process of vegetative reproduction.