Science M.C.Q. [I MARKS]

The number of nuclei present in a zygote is one.

The transformation of the larva into an adult through drastic changes is called metamorphosis. Metamorphosis occurs in frog and silk moth.

Internal fertilization occurs in the female body.

Reproduction without the fusion of gametes is known as asexual reproduction. The offspring are genetically identical.

Hydra reproduces by budding.

Oviducts is not a part of male reproductive system. It is a part of female reproductive system.

Testes contain seminiferous tubules.

Umbilical cord transports urea, antibodies and carbon dioxide.

Amoeba, a unicellular organism reproduces by binary fission.

In females, ovaries are primary sex organs.

The fallopian tubes have an internal wall lined with fingerlike projections.

Asexual reproduction is a method producing generally identical offspring.

Fertilisation is the fusion of male and female gametes. In human beings, it takes place in the fallopian tube of the female reproductive system.

Reproduction is one of the important characteristics of living things. The ability of organism to produce young ones of its own kind is called reproduction. It is essential for the continuity of species.

Spermatozoa are present in the mil of frog.

The function of the secretions of cowpers gland is to serve as a lubricant.

The aquatic animals in which fertilisation occurs in water are oviparous with external fertilisation. They lay eggs and release sperms outside body in the water for fertilisation to take place. The young one top is formed outside the body in water from the zygote formed inside eggs.

Frog, silk moth and mosquito undergo metamorphosis whereas fish does not show metamorphosis.

The adrenal gland is called the gland of emergency because it releases the hormone, epinephrine or adrenaline, which prepares the body to act when we are in stressful or potentially dangerous situation. Hence, it is also known as the fight-or flight hormone.

All living organisms reproduce.

Budding, binary fission, spore formation are types of asexual reproduction.

Female gamete in humans is called ova/egg. It is produced by the ovaries. The male gamete called sperm fuses with the egg to form a zygote.

Binary fission is a type of asexual reproduction seen in unicellular organisms. In this method, first the nucleus divides followed by cytoplasmic division. This forms two daughter cells from one parent cell. Therefore, Paramecium dividing itself to form two daughter cells represents binary fission.

Characters that are transmitted from parents to offspring during sexual reproduction show both similarities and variations with parents.

The fertilization which takes place outside the female body is called external fertilization. In external fertilization the female animal eggs are fertilized by sperm outside her body. External fertilization is very common in aquatic animals such as frog, fish and star-fish etc. Animals exhibiting external fertilisation produce a large number of gametes to ensure better chance of fertilisation.

Fertilization in humans take place in the female body. The sperms of men are introduced by penis into female’s body through vagina. The sperms then pass through the uterus and reach to oviducts. It is here, that sperms combines with egg to forms zygote (i.e. Fertilization occurs).

Ovary is the structure that occurs in the reproductive system of flowering plants as well as of humans. In both of them, it produces female gametes called egg.

The production of new individuals from their parents is known as reproduction. Reproduction is essential for living organisms in order to continue the species.

Hydra is a multicellular organism which reproduce by budding.

Asexual reproduction is the simplest method of reproduction. It takes only in those animals whose bodies have a simple structure. In asexual reproduction the young one or offspring produced is an exact copy of the parent. Asexual reproduction is a method producing generally identical off-springs.

In human beings, sexual reproduction takes place by the combination of gametes, i.e. sperm and egg, formed in male and female, respectively. The fusion of gametes is called fertilisation. The fusion forms a zygote, which divides repeatedly to form the embryo. The embryo gets implanted in female uterus for further development to form foetus.