Tag: reproduction in earthworm

Questions Related to reproduction in earthworm

Read the assertion (A) and reason (R) carefully to mark the correct option out of the options given below:
A. There are some plants which have in their life-cycles neither the process of fertilization nor they have meiosis.
R. In these plants, the vegetative or somatic plant body helps in the propagation of the plant.

evs seed becomes plant introduction to reproduction vegetative reproduction budding, vegetative propagation and spore formation earthworm - reproductive system reproduction in earthworm other modes of vegetative propagation the journey of seeds

  1. Both the Assertion and the Reason are true and the reason is a correct explanation of the assertion.

  2. Both the Assertion and Reason are true but the reason is not a correct explanation of the assertion.

  3. The Assertion is true but the Reason false.

  4. Both the Assertion and Reason are false.

  5. The assertion is false but reason is true.

Show answer
Correct Option: A
Explanation:

Organisms reproduce for perpetuation of species because individuals have a limited life span. Organisms may reproduce sexually as well as asexually. The sexual reproduction involves formation of haploid gametes through the process of reduction division or meiosis. The haploid gametes fuse during fertilization to form diploid zygote. Thus, restoring the normal ploidy. The asexual reproduction does not involves gamete formation through meiosis or their fertilization. The vegetative propagation in plants is a type of asexual reproduction in which plant body is propagated directly from some vegetative part of adult plant.

Therefore, the correct answer is option A.

Fortilization in earthworm is

zoology earthworm earthworm - reproductive system reproduction in earthworm introduction to reproduction

  1. Cross fertilization

  2. Mutual fertilization

  3. Self fertilization

  4. None of these

Show answer
Correct Option: A
Explanation:

Earthworm is a bisexual or hermaphrodite but always shows cross-fertilization due to polyandrous conditions.

Number of ovaries present in earthworm is

zoology earthworm earthworm - reproductive system reproduction in earthworm introduction to reproduction

  1. One

  2. Two

  3. Four

  4. Eight

Show answer
Correct Option: B
Explanation:

The number of ovaries present in Earthworm is one pair of ovaries. One pair of ovaries is attached at the intersegmental septum of the 12th and 13th segments. Ovarian funnels are present beneath the ovaries which continue into the oviduct and open on the ventral side.

So the correct answer is "Two".

In earthworms, self fertilization does not occur due to 

zoology earthworm earthworm - reproductive system reproduction in earthworm introduction to reproduction

  1. Protandry

  2. Protogyny

  3. Both A and B

  4. Dichogamy

Show answer
Correct Option: A
Explanation:

Earthworms are monoecious or hermaphrodite (have both male and female sex organs) but are protandrous. The testes mature earlier than ovaries and hence, self-fertilisation is avoided.
Thus, the correct answer is option A.

Number of testes in Earthworm is

zoology earthworm earthworm - reproductive system reproduction in earthworm introduction to reproduction

  1. One

  2. Two

  3. Four

  4. Eight

Show answer
Correct Option: C
Explanation:

Earthworm is hermaphrodite. There are two pairs of testes present in the 10th and 11th segments. Their vasa deferentia run up to the 18th segment where they join the prostratic duct. The prostate and spermatic duct open to the exterior by a pair of male genital pores on the ventrolateral side of the 18th segment. 

So the correct answer is "Four".

The female genital aperture, in earthworm is present ventrally on the segment

zoology earthworm earthworm - reproductive system reproduction in earthworm introduction to reproduction

  1. 10th

  2. 12th

  3. 14th

  4. 18th

Show answer
Correct Option: C
Explanation:

Four pairs of spermathecae are located in 6th-9th segments. They receive and store spermatozoa during copulation. One pair of ovaries is attached at the inter-segmental septum of the 12th and 13th segments. Ovarian funnels are present beneath the ovaries which continue into the oviduct, join together and open on the ventral side as a single median female genital pore on the 14th segment.

So the correct answer is '14th'.

Spermathecae of Earthworm

zoology earthworm earthworm - reproductive system reproduction in earthworm introduction to reproduction

  1. Store sperms

  2. Produce sperms

  3. Activate sperms

  4. Bring about fertilization

Show answer
Correct Option: A
Explanation:

In Earthworm there are four pairs of spermathecae which are located in the 6th - 9th segments one pair in each segment. They receive and store spermatazoa during copulation. One pair of ovaries is attached at the inter-segmental septum of the 12th and 13th segments.

So the correct answer is 'Store sperms'.

In Earthworm male genital apertures are present ventrally in the segment

zoology earthworm earthworm - reproductive system reproduction in earthworm introduction to reproduction

  1. 14th

  2. 15th

  3. 17th

  4. 18th

Show answer
Correct Option: D
Explanation:

A pair of male genital pores is present on the ventrolateral sides of the 18th segment. Numerous minute pores called nephridiopores open on the surface of the body. In each body segment, except the first, last and clitellum, there are rows of S-shaped setae, embedded in the epidermal pits in the middle of each segment.

So the correct answer is '18th'.

The animal which does not show any metamorphosis or larval stage is

zoology earthworm earthworm - reproductive system reproduction in earthworm introduction to reproduction

  1. Pheretima posthuma

  2. Asterias

  3. Musca domestica

  4. Butterfly

Show answer
Correct Option: A
Explanation:

Asterias, Musca domestica and butterfly include a larval stage in their life cycle. Whereas in the case of Pheretima, there is no larval stage involved and the development is direct mode of development.

So, the correct answer is 'Pheretima posthuma'.

Copulation period of Earthworm is

zoology earthworm earthworm - reproductive system reproduction in earthworm introduction to reproduction

  1. One hour

  2. Two hours

  3. Four hours

  4. About one week

Show answer
Correct Option: A
Explanation:

Answer is option A i.e. "One hour"
Copulation lasts for about an hour. Then the worms separate and later (after some day) they lay their eggs in cocoon. Cocoon formation takes place after copulation, when ovaries mature.