Tag: zoology

Questions Related to zoology

A biology student has to distinguish the anterior and posterior end of Pheretima morphologically. For it, he can observe/ locate

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

  1. Parapodia

  2. Eyes

  3. Clitellum

  4. Tentacles

Show answer
Correct Option: C
Explanation:

The anterior region of Pheretima consists of a thick, saddle-like ring found in the epidermis known as Clitellum This structure is easily visible with naked eyes hence a person can easily distinguish the anterior and posterior end of pheretima.

So the correct answer is 'Clitellum'.

Which of the following statements is not correct regarding sexuality in organisms?

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

  1. When both male and female flowers are present on the same plant, the condition is said to be monoecious and is present in cucurbits and coconuts

  2. When both male and female flowers are present on the separate plants, the condition is said to be dioecious and is present in papaya and date palms

  3. In earthworm, both male and female sex organs are present in the same individual and therefore, self-fertilisation occurs in them

  4. Cockroach is an unisexual animal and exhibit sexual dimorphism

Show answer
Correct Option: C
Explanation:

Cross-fertilization occurs in many hermaphrodite animals as in earthworm. It is due to the fact that their male and female reproductive organs mature at different times.

Thus, the correct answer is 'In earthworm, both male and female sex organs are present in the same individual and therefore, self-fertilization occurs in them.'

One of the following is wrong about male reproductive organs of earthworm

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

  1. Two fluid-filled testis sacs with pair of spermiducal funnel attached to vasa differentia

  2. Two pairs of seminal vesicles

  3. Four pairs of spermathecae

  4. One pair of prostate gland

  5. All of the above

Show answer
Correct Option: E
Explanation:
Earthworm is a hermaphrodite i.e. ovaries and testes are present in the same individual. There are two pairs of testes present in the 10th and 11thsegments. Testes are enclosed by a fluid-filled sac called testes sac. Testis sec with the pair of a funnel attached to the vasa deferentia, which run up to the 18th  segment where they join the prostatic duct. In the earthworm reproductive system, four pairs of spermathecae, two pairs of seminal vesicles and one pair of the prostate gland are present.
So, 'All of the above'

Larva is not found in the life of 

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

  1. Pheretima

  2. Taenia

  3. Musca

  4. Rana

Show answer
Correct Option: A
Explanation:

In Pheretima, a cocoon contains many fertilised eggs but only one embryo completes development, while other ova serve as nurse cells. The development is direct without a free larval stage. After the development of 2-3 weeks, the young worm crawls out of the cocoon. So, the correct answer is option A.

In earthworm, the process of spermatogenesis takes place in 

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

  1. Spermatheca

  2. Testis

  3. Testis sac

  4. Seminal vesicle

Show answer
Correct Option: B
Explanation:

There are two pairs of testes, which are situated in the 10$^{th}$ and 11$^{th}$ segments on each side of the alimentary canal. The germinal epithelium of the testis gives rise to the sperm cells by spermatogenesis. So, the correct answer is option B.

Which of the following is marine leech?

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

  1. Haemadipsa

  2. Bonellia

  3. Hirudinaria

  4. None of the above

Show answer
Correct Option: B
Explanation:

Leech belongs to phylum Annelida. The 'green spoonworm' (Bonellia viridis) lives in a marine habitat. It shows sexual dimorphism. It is also known as the biocidal properties of a pigment in its skin. It is found in the north-eastern Atlantic, Indian and Pacific Oceans and the Mediterranean and Red seas. It is pale- to dark-green in colour, with a 15 cm long, round or sausage-shaped body. Hence, option B is correct.

In Earthworm, ovary is situated in segment

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

  1. 13

  2. 9

  3. 10

  4. 26

Show answer
Correct Option: A
Explanation:

Earthworms are hermaphrodites; that is, they have both male and female sexual organs.  The two or four pairs of seminal vesicles produce, store and release the sperm via the male pores. Ovaries and oviducts are in segment 13 release eggs. Ovarian funnels are present beneath the ovaries which continue into the oviduct, join together.

So the correct answer is '13'.

Spermathecae occur in earthworm in

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

  1. 6th-9thsegments

  2. 6th-10th segments

  3. 6th-11th segments

  4. 5th-8th segments

Show answer
Correct Option: A
Explanation:

The spermathacae are also called as receptaculum seminis. species of earthworms have four pairs of spermathecae one pair each in the 6th, 7th, 8th, and 9th segments. The spermathecae receive and store the spermatozoa of another earthworm during copulation. They are lined with epithelium and are variable in shape: some are thin, heavily coiled tubes.

So the correct answer is '6th - 9th segments'.

Which one correctly describes the location of body parts in Pheretima?

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

  1. Two pairs of accessory glands in 1618 segments

  2. Two pairs of testes in 10th and 11th segments

  3. Four pairs of spemathecae in 47 segments

  4. One pair of ovaries attached over septum 1415 segments

Show answer
Correct Option: B
Explanation:

Two pairs of accessory glands are present in 17th and 19th segments. 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.

Two pairs of testes are present on the 10th and 11th segments.
So the correct answer is 'Two pairs of testes in 10th and 11th segments'.

Choose the correct answers from the alternatives given.
Flukes and tapeworms:

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

  1. show cephalization

  2. have well-developed reproductive systems

  3. have well-developed nervous systems

  4. have a tube-within-a-tube body plan

Show answer
Correct Option: B
Explanation:

Tapeworm and fluke worms belong to class Platyhelminthes. They both are having well developed reproductive systems.

So the correct answer is "have well-developed reproductive systems".