Olympiad Test: Reproduction In Animals - UPSC MCQ

Tadpole is the developing stage of:
The correct answer is C: Frogs. Tadpoles are the larval stage of frogs. They undergo a metamorphosis process to transform into adult frogs. Here is a detailed explanation:
1. Tadpole:
- Tadpoles are the early life stage of frogs.
- They hatch from eggs laid by adult frogs in water bodies such as ponds, lakes, or streams.
- Tadpoles have a long tail and lack limbs.
2. Metamorphosis:
- Tadpoles undergo a process called metamorphosis to transform into adult frogs.
- During this process, they go through various developmental changes.
- Their tails shrink and eventually disappear, while hind legs and then front legs develop.
- Their lungs develop, allowing them to breathe air instead of relying on gills.
3. Transformation into adult frogs:
- As tadpoles continue to grow and develop, they gradually resemble adult frogs.
- They begin to develop the ability to live on land and adapt to a terrestrial lifestyle.
- Once they have completed their metamorphosis, they leave the water and become fully functioning adult frogs.
In conclusion, tadpoles are the developing stage of frogs. They undergo a remarkable transformation from aquatic creatures with tails to terrestrial adult frogs with legs.

The fusion of male and female gamete is called fertilization. Internal fertilization takes place in humans. Male releases sperms inside female's body. Sperms and ovum fuse together in fallopian tube, during fertilization, the nuclei of the sperm and the egg fuse to form a single nucleus.

The fusion of these two cells is called fertilization and it produces a diploid cell with 46 chromosomes - twice the amount found in each gamete. The fertilized egg is now called a zygote and has just the right amount of DNA needed for normal human development.

Eggs are formed in the:


There are four options given, and the correct answer is option C: Ovary. Let's explain in detail why this is the correct answer:
1. Testes:
- Testes are the male reproductive organs responsible for the production of sperm.
- They do not produce eggs, but rather sperm cells.
2. Penis:
- The penis is the male external genital organ.
- It does not play a role in the formation of eggs.
3. Ovary:
- The ovary is the female reproductive organ responsible for the production of eggs.
- It is located in the lower abdomen and contains thousands of immature eggs.
- During the menstrual cycle, one or more eggs are released from the ovary in a process called ovulation.
4. None of these:
- This option is incorrect, as eggs are indeed formed in the ovary.
In summary, eggs are formed in the ovary, making option C the correct answer.

Option B because it occur both of reproduction sexual and asxual.

A sperm is a germ cell. It is one of two types of reproductive cells found in sexually reproducing animals. Sperm is produced by males. It consists of three parts. i.e  Head, middle, tail.

A foetus is the unborn offspring of an animal that develops from an embryo. In human prenatal development, fetal development begins from the ninth week after Fertilisation  and continues until birth. 

Definition of Viviparous Organisms:
Viviparous organisms are those that give birth to live young ones rather than laying eggs.
Explanation:
Viviparity is a reproductive mode where the offspring develop inside the parent's body and are born alive. Let's break down the options given to determine the correct answer:
A: Produce eggs:
- This option refers to organisms that lay eggs, which is not characteristic of viviparous organisms.
B: Produce young ones:
- This option accurately describes viviparous organisms. They give birth to live young ones that have developed inside the parent's body.
C: Produce sometimes eggs or sometimes young ones:
- This option describes organisms that exhibit both viviparous and oviparous reproduction. Viviparous organisms exclusively give birth to live young ones, so this option is incorrect.
D: None of these:
- This option is incorrect as viviparous organisms do produce young ones.
Therefore, the correct answer is B: Produce young ones because viviparous organisms give birth to live offspring rather than laying eggs.

Cloning:
Cloning is a mode of reproduction where an organism is produced that is genetically identical to its parent. It involves the creation of an exact copy or clone of an organism, either naturally or artificially.
Asexual Reproduction:
Asexual reproduction is a type of reproduction that does not involve the fusion of gametes (sex cells) from two parents. It only involves one parent and the offspring produced are genetically identical to the parent.
Sexual Reproduction:
Sexual reproduction is a type of reproduction that involves the fusion of gametes from two parents, typically a male and a female. It leads to genetic variation in the offspring due to the combination of genetic material from both parents.
Cloning and Reproduction:
Based on the given options, the correct answer is B: Asexual reproduction. Cloning is a form of asexual reproduction because it involves the production of genetically identical offspring without the involvement of gametes or the fusion of genetic material from two parents.
Cloning can occur naturally in certain organisms, such as bacteria and plants, through processes like binary fission and vegetative propagation. It can also be artificially induced in laboratory settings through techniques such as somatic cell nuclear transfer (SCNT).
In conclusion, cloning is a mode of asexual reproduction where genetically identical offspring are produced without the involvement of gametes or the fusion of genetic material from two parents.

Explanation:
Sperms are not called female gametes. Here's why:
1. Gametes: Gametes are reproductive cells that fuse together during sexual reproduction to form a new individual. In humans, the male gametes are called sperm cells, while the female gametes are called egg cells or ova.
2. Sperms: Sperms are the male gametes produced by the male reproductive system. They are specialized cells with a head, midpiece, and a tail. Sperms are responsible for fertilizing the egg, resulting in the formation of a zygote.
3. Female Gametes: Female gametes, on the other hand, are produced by the female reproductive system. They are called egg cells or ova. Unlike sperm cells, they are relatively larger and contain necessary nutrients and organelles to support fertilization and early development.
4. Fertilization: During sexual reproduction, a sperm cell penetrates an egg cell, resulting in fertilization. This process combines genetic material from both parents and leads to the formation of a zygote, which eventually develops into an embryo.
In conclusion, sperms are male gametes, not female gametes.

Explanation:

Testes are male reproductive organs which produce sperms.

Answer: True
Reasoning:
Here is a detailed explanation of why the answer is true:
- The testes are a pair of male reproductive organs located in the scrotum, which is an external sac of skin.
- The primary function of the testes is to produce sperms, which are the male reproductive cells necessary for fertilization.
- Sperms are produced within the seminiferous tubules present in the testes.
- The testes also produce testosterone, a hormone responsible for the development and maintenance of male reproductive organs and secondary sexual characteristics.
- The production of sperms starts during puberty and continues throughout a man's life.
- The sperms produced in the testes are stored and matured in the epididymis, another part of the male reproductive system, before being ejaculated during sexual intercourse.
In conclusion, the statement that "Testes are male reproductive organs which produce sperms" is true.

Introduction:
All living animals reproduce to produce new young ones. This statement is either true or false. Let's analyze the concept of reproduction in living animals to determine the correct answer.
Reproduction in living animals:
- Reproduction is a fundamental characteristic of all living organisms, including animals.
- It is the process by which new individuals of the same species are produced, ensuring the continuation of the species.
Modes of animal reproduction:
Animals can reproduce in different ways, depending on their species and characteristics. Some common modes of animal reproduction include:
1. Sexual reproduction:
- In sexual reproduction, two individuals of the opposite sex are involved. They produce specialized reproductive cells called gametes (sperm and egg).
- The fusion of these gametes during fertilization leads to the formation of a zygote, which develops into a new individual.
- Sexual reproduction promotes genetic diversity and variation within a species.
2. Asexual reproduction:
- In asexual reproduction, a single individual is capable of producing offspring without the involvement of another individual.
- This can occur through various mechanisms, such as budding, fission, fragmentation, or parthenogenesis.
- Asexual reproduction results in offspring that are genetically identical or nearly identical to the parent.
3. Other modes of reproduction:
- Some animals exhibit unique modes of reproduction, such as hermaphroditism (possessing both male and female reproductive organs), sequential hermaphroditism (changing sex during their lifetime), or external fertilization (releasing eggs and sperm into the environment).
4. Birds are Oviparous animals lay eggs, rather than giving birth to live young.
Conclusion:
Based on the information provided, it is evident that all living animals reproduce to produce new young ones but Birds are Oviparous animals lay eggs, rather than giving birth to live young. This makes the statement "All living animals reproduce to produce new young ones" False. Reproduction is a vital process for the survival and continuation of animal species.

Budding is a form of asexual reproduction in which a new organism develops from an outgrowth or bud due to cell division at one particular site. Organisms such as hydra use regenerative cells for reproduction in the process of budding. 

Amoeba can't reproduce by the process of budding.

Explanation:
Snakes are indeed oviparous, meaning they reproduce by laying eggs. Here's a detailed explanation:
1. Definition of oviparous:
- Oviparous is a term used to describe animals that lay eggs to reproduce.
- These eggs are typically laid outside the body and hatch after a certain period.
2. Snakes and egg-laying:
- Snakes are classified as reptiles, and most reptiles are oviparous.
- Female snakes produce eggs that contain developing embryos.
- The eggs are then deposited in a suitable location, such as underground burrows or nests, where they are protected until they hatch.
3. Snake reproductive system:
- Female snakes have a reproductive system specialized for egg production.
- They have a pair of ovaries that contain developing eggs.
- When the eggs are fully developed, they are released into the oviducts.
4. Oviducts and egg-laying:
- The oviducts in snakes are responsible for transporting the eggs from the ovaries to the cloaca.
- The cloaca is a common opening for excretory, reproductive, and digestive systems in reptiles.
- When the time is right, the female snake lays the eggs through the cloaca.
5. Egg incubation:
- After laying the eggs, the female snake does not provide any further care.
- The eggs are left to develop and hatch on their own.
- The incubation period varies depending on the species and environmental conditions.
6. Viviparous snakes:
- While most snakes are oviparous, there are a few exceptions.
- Some snake species, such as boas and vipers, are viviparous.
- Viviparous snakes give live birth to fully developed young instead of laying eggs.
In conclusion, snakes are oviparous because they reproduce by laying eggs. The female snake produces eggs, which are then laid outside the body and hatch after a certain incubation period.

Earthworms are Simultaneous hermaphrodite, meaning worms have both male and female reproductive organs. During sexual intercourse among earthworms, both sets of sex organ are used by  both worms.
Earthworms only reproduce through sexual reproduction.
So, the given statement is false.

Cloning is a method of sexual reproduction.
Cloning is not a method of sexual reproduction. Sexual reproduction involves the fusion of male and female gametes (sperm and egg) to produce offspring with a combination of genetic material from both parents. Cloning, on the other hand, is a form of asexual reproduction where an organism is produced with the same genetic material as the parent.
Here are some key points to explain why cloning is not a method of sexual reproduction:
1. Asexual reproduction: Cloning is a type of asexual reproduction where a single parent organism produces genetically identical offspring without the involvement of gametes or fertilization.
2. Genetic material: In cloning, the genetic material of the offspring is identical to that of the parent organism. There is no combination of genetic material from two different parents, as in sexual reproduction.
3. Methods of cloning: There are different methods of cloning, such as somatic cell nuclear transfer (SCNT) or artificial embryo twinning. These techniques involve the replication of the genetic material from a single parent organism.
4. Offspring characteristics: Cloned offspring have the same genetic characteristics as the parent organism, including traits and predispositions to certain diseases. In sexual reproduction, offspring inherit a combination of traits from both parents, resulting in genetic diversity.
In conclusion, cloning is not a method of sexual reproduction. It is a form of asexual reproduction where genetically identical offspring are produced from a single parent organism.

Answer:
The statement "Ovary is the main male reproductive organ" is incorrect. The ovary is actually the main female reproductive organ. Here's a detailed explanation:
Male Reproductive System:
- The male reproductive system consists of several organs, including the testes, epididymis, vas deferens, ejaculatory ducts, seminal vesicles, prostate gland, and penis.
- The main male reproductive organ is the testes, which are responsible for producing sperm and the male sex hormone, testosterone. Sperm production occurs within the testes.
Female Reproductive System:
- The female reproductive system consists of several organs, including the ovaries, fallopian tubes, uterus, cervix, and vagina.
- The main female reproductive organs are the ovaries, which are responsible for producing eggs (ova) and female sex hormones, such as estrogen and progesterone. Egg production occurs within the ovaries.
Differences Between Male and Female Reproductive Systems:
- In males, the testes produce sperm, which is necessary for fertilization, while in females, the ovaries produce eggs.
- The male reproductive system is responsible for delivering sperm to the female reproductive system, while the female reproductive system is responsible for nurturing and supporting the fertilized egg.
- The male reproductive system includes external genitalia (penis and scrotum), while the female reproductive system includes internal genitalia (uterus, fallopian tubes, and ovaries).
In conclusion, the main male reproductive organ is the testes, not the ovary. The ovary is the main female reproductive organ responsible for egg production.

After fertilisation, zygote is formed
- The process of fertilisation occurs when the sperm cell fuses with the egg cell, resulting in the formation of a zygote.
- The zygote is the initial stage of development in multicellular organisms, including humans.
- It contains a complete set of chromosomes, half from the sperm cell and half from the egg cell.
- The fusion of the genetic material from both parents leads to the formation of a unique individual with a combination of traits inherited from both parents.
- The zygote undergoes a series of cell divisions known as cleavage to form an embryo.
- During cleavage, the zygote divides into smaller cells called blastomeres.
- The blastomeres continue to divide and form a solid ball of cells called a morula.
- The morula then undergoes further development and eventually forms a blastocyst.
- The blastocyst consists of an outer layer of cells called the trophoblast and an inner cell mass.
- The inner cell mass further differentiates into the three germ layers, which give rise to different tissues and organs in the developing embryo.
- Overall, the formation of the zygote is a crucial step in the reproductive process and marks the beginning of embryonic development.

In- vitro fertilization ( IVF) can help to achieve pregnancy when other treatments have not worked. The process involves fertilizing an egg outside the body, and implanting it to continue the pregnancy.