Class 7 Science Chapter 12 MCQ

Here, all the statements are correct. Hence, your answer will be option [D].

Here, all the statements are correct. Hence, your answer will be option [D].

Here, all the statements are correct. Hence, your answer will be option [D].

Some plants reproduce themselves from leaves. One example of a plant which can reproduce from its leaves is “bryophyllum”. When a mature leaf of the “bryophyllum” plant falls on the ground, they grow into a new plant.

The axillary buds can give rise to new plants. Vegetative buds of a plant are used as a means of asexual reproduction for producing new plants.

Budding is an asexual method of reproduction. In budding, a small part of the body of the parent plant grows out as a bulb-like projection called “bud” which then detached and becomes a new plant. Yeast is a single celled plant which reproduce by budding.

Here, all the statements are correct. Hence, your answer will be option [D].

Most plants have roots, stems and leaves. These are called the vegetative parts of a plant. After a certain period of growth, most plants bear flowers. The flowers perform the function of reproduction in plants. Flowers are the reproductive parts of a plant.

Here, all the statements are correct. Hence, your answer will be option [D].

Here, all the statements are correct. Hence, your answer will be option [D].

The main parts of a flower are receptacle, sepals, petals, stamen and pistil. Receptacle is the base of flower where all parts of a flower are attached. Sepals is the green leaf like parts of a flower which can be seen in a form of bud. Petals are the colorful part of flower. Stamen is the male reproductive organ of a plant. Pistil present in the center of a flower. It is the female reproductive organ of the plant. The stamen made of two parts “filament and anther”. And anther makes the “pollen grains” and stores them. This further transfer of pollen grains makes pollination, fertilization and getting a fruit (with seed inside it). And again this seed germinate into a new plant which bears flowers after certain time.

Here, all the statements are correct. Hence, your answer will be option [D].

The process in which the male gamete present in pollen grain fuses or joins with the female gamete present in ovule to form a new cell called zygote, is called fertilization. After fertilization two main things happen. As the ovule present in ovary grows to become a seed. After fertilization ovary of a flower develops and becomes a fruit (with seeds inside it). Thus, fruit is the ripened ovary of a flower.

In the presence of water and nutrients, algae grow and multiply rapidly by fragmentation. An alga breaks up into two or more fragments, each of which grow into new individuals. This process covers a large area in a short period of time.

Stamen is the male reproductive organ of the plant whereas stigma is the female reproductive organ of the plant.

Here, all the statements are correct. Hence, your answer will be option [D].

The eye of the potato is the same as the bud is to “Bryophyllum” leaf. Both the structures are vegetative propagules. They can form a new plant from them. This method of asexual reproduction through the vegetative parts of the existing plant is called “vegetative propagation”.

The process in which the male gamete present in pollen grain fuses or joins with the female gamete present in ovule to form a new cell called zygote, is called fertilization. After fertilization two main things happen. As the ovule present in ovary grows to become a seed. After fertilization ovary of a flower develops and becomes a fruit (with seeds inside it). Thus, fruit is the ripened ovary of a flower.

Stamen is the male reproductive organ of a plant. Pistil present in the center of a flower. It is the female reproductive organ of the plant. The stamen made of two parts “filament and anther”. And anther makes the “pollen grains” and stores them. Pistil is the female reproductive organ of the plant. A pistil is made of three parts; stigma, style and ovary. The ovary makes ovules and stores them. Ovule contain the female gametes or female sex cells of the plant. Thus, “anther and ovary” are the parts that produce male and female gametes respectively.

Some plants reproduce themselves from leaves. The leaves of some plants developed buds on them. Such leaves having buds can be used as a structure of vegetative reproduction in plants. One example of a plant which can reproduce from its leaves is “bryophyllum”. When a mature leaf of the “bryophyllum” plant falls on the ground, they grow into a new plant.

Cutting are a means of asexual reproduction in plants. The new plant formed from a cutting is exactly similar to the parent plants. The plants like rose, money plant, grapes, sugar cane, bananas, cactus can be grown by cutting method or by using stem cutting or branch cutting. But maize or corn is a plant belonging to the family of grasses. It does not flower readily and seed production is unusual except in its native habitat. Under natural conditions, maize reproduces only by seed production.

For the male gamete to be able to combine with the female gamete, it is necessary that first the pollen grains from the anther of stamen of a flower should be carried to the stigma of pistil. The transfer of pollen grains from the anther of a stamen to the stigma of pistil is called pollination. When pollination is done by insects such as bees and butterflies, called cross-pollination.

When a seed is sown in the moist soil, it begins to grow and called germination. And in this stage, the seed coats splits (as tiny root grows) downward and (the shoot grows) upwards. The seedling grows further and ultimately forms a new plant. And after a certain period, the plant bears flowers once again.

The seeds and fruits dispersed by wind either have wing like structures or they have hair or they are very small and light, which helps them to be easily carried away by the blowing wind. Such as the seed of drumstick plant, the seeds of madar plant, the plants like grasses and orchids have very small and light seeds which can be easily blown away by the wind for dispersal. The seeds of water lily plant and coconut plant are dispersed by water.

A seed on germination grows into a new plant and fertilization in plants can only occur after pollination (i.e. only when pollen grains have fallen on the stigma of a flower). Other statements are incorrect as a plant bearing bisexual flowers can undergo sexual reproduction itself as both male and female reproductive organs are present. Also, along with insects, wind and water are also agents of pollination.