Science M.C.Q

A germ cell has 14 pairs of chromosomes i.e. half the number of chromosomes present in the normal body cell of an organism.

The offsprings formed by the method of asexual reproduction have greater similarity among themselves. This is because asexual reproduction involves only one parent and does not require gametes.

Plasmodium reproduces by multiple fission and causes malaria.

The anther produces pollen grains which are male gametes and the ovary produces ovules which are female gametes.

The ovary of a flower has ovules and the ovary of a human female has eggs.

Hepatitis is not a sexually transmitted disease.

In binary fission, a single-celled organism divides into two daughter cells that are identical to their parent.

Fertilisation is the fusion of two gametes in a sexual reproduction. It produces genetically different off springs and does not lead to the formation of clones.

Micropropagation is a tissue culture method of asexual reproduction in plants, which forms callus.

Amoeba, yeast and bacterium are unicellular organism that reproduce asexually.

Sexual reproduction in flowers requires two types of gametes, namely pollen grains and ovules. The fusion of the gametes results in the formation of the zygote. This process is termed as fertilisation.

Fern is a non-flowering plant which reproduces by forming spores.

In corals and sponges, the buds remain attached to their parents permanently, and form colonies.

when a female starts to menstruate, it indicates that she is sexually mature and can start her reproductive life.

The pollens are transferred to the stigma by pollination, the gametes then fuse and undergo fertilisation to form the zygote which develops into an embryo and, then, into a seed.

Hydra and Planaria reproduce through regeneration. They can regenerate fully from their cut body parts.

Offsprings produced by sexual reproduction show similarities as well as variations with parents.

The oviduct is a part of the female reproductive system in humans.

Hyphae are the fine thread-like structures of the fungi that are spread on the whole surface of a slice of bread.

Leishmania is the protozoan that has flagellum at its one end.

It reproduces by multiple fission.

Hydra is a tiny animal that has tentacles on one end, and reproduces by the method of budding.

The factors responsible for the rapid spreading of bread mould on slices of bread are the presence of a large number spores in air and the presence of moisture and nutrients in bread that act as food for the fungi.

Plants have sexual reproductive organs such as stamen and pistil. A fruit is formed after fertilisation in plants.

Scion is the upper part of the graft, which does not have roots.

The radicle of a seed forms the root after germination.

Y represents the testes that produce sperms and V represents the prostrate gland that produces seminal fluid.

The genetically identical offsprings formed by asexual reproduction are called clones.

Genes carry the genetic information and are responsible for the transmission of characteristics from parents to offspring.

The gametes have half the number of chromosomes. After their fusion, the zygote thus formed has a full set of chromosomes. Therefore, the numbers of chromosomes in parents and offsprings of a particular species remain constant.

An anther contains male gametes called pollen grains.

Gametes of flowers fuse to form a zygote. This zygote develops into an embryo those later forms the seed.

Gonorrhoea is caused by bacteria, which spreads through sexual contact.

The exchange of nutrients, oxygen and waste products between the embryo and the mother's body takes place through the umbilical cord.

Yeast reproduces by budding.

Hydra can reproduce by the method of budding similar to yeast, and also by regeneration as in the case of Planaria.

The surgical method of birth control in females is termed as tubectomy.

It is a multicellular organism that reproduces by budding.

The ability of a cell to divide itself into several cells during reproduction is called multiple fission.

The vas deferens is a part of the male reproductive system in humans.

It reproduces by regeneration.

Fungi reproduce asexually through the formation of spores.

The sexual reproduction involves two parents of the same species. Thus, both of them contribute to the genetic material of the offspring and bring about the variations.

In internal fertilisation, there is no need for the production of a large number of gametes as it provides a safe environment.

Asexual reproduction involves only one parent; therefore, the offsprings are genetically identical.

Yeast is the unicellular organism which reproduces by budding.

Hydra is a simple multicellular animal that has tentacles and lives in freshwater. It reproduces by budding.

It reproduces by the method of fragmentation in which the filament is broken down into small pieces.

The number of chromosomes in a human sperm is half the number of chromosomes in a zygote, i.e., their ratio is 2 : 1.

It reproduces by regeneration.