Tag: introduction to reproduction

Questions Related to introduction to reproduction

Female genital aperture in earthworm is found in 

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

  1. 10$^{th}$ segment

  2. 12$^{th}$ segment

  3. 14$^{th}$segment

  4. 18$^{th}$segment

Show answer
Correct Option: C
Explanation:

The oviduct funnel located below ovary opens into a short conical tube called oviduct. Two oviducts fuse together and open outside through female genital aperture located in the 14$^{th}$ segment.

So, the correct option is '14$^{th}$ segment.'.

Earthworms are hermaphrodite and reproduce primarily by

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

  1. Self-fertilization

  2. Cross-fertilization

  3. Asexualy

  4. All of the above

Show answer
Correct Option: B
Explanation:

Earthworms are hermaphrodites but they cannot fertilize their own eggs because of their relative position of male and female genital aperture and they are protrandous (i.e. male sex mature earlier than female gametes). So, cross-fertilization takes place instead of self-fertilization.

So, the correct option is 'Cross-fertilization'.

Nutritive substance for cocoon secreted by

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

  1. Mucous cells

  2. Albuminous cells

  3. Yellow cells

  4. All of these

Show answer
Correct Option: A
Explanation:

The clitellum plays an important role in reproduction. Its glands produce mucous which becomes a sheath containing nutritive material. The sheath slides forwards, collecting eggs and sperm from the genital openings of the worm. The sheath finally slides off from the head of the worm. As it separates from the worm, its ends are sealed. It now becomes a cocoon.

So, the correct option is 'Mucous cells'.

In Pheretima, the dorsal surfaces is marked by a mid dorsal line, whereas the ventral surface is distinguish the present of

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

  1. Dorsal blood vessels

  2. Genital pores

  3. Absence of setae

  4. Parapodia

Show answer
Correct Option: B
Explanation:

Genital pores for both male and female organs are present on the ventral side of the earthworm. Also, setae are present on the ventral side.

So, the correct option is 'Genital pores'.

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.