Tag: introduction to reproduction
Questions Related to introduction to reproduction
Female genital aperture in earthworm is found in
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10$^{th}$ segment
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12$^{th}$ segment
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14$^{th}$segment
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18$^{th}$segment
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.
Earthworms are hermaphrodite and reproduce primarily by
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Self-fertilization
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Cross-fertilization
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Asexualy
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All of the above
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.
Nutritive substance for cocoon secreted by
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Mucous cells
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Albuminous cells
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Yellow cells
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All of these
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.
In Pheretima, the dorsal surfaces is marked by a mid dorsal line, whereas the ventral surface is distinguish the present of
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Dorsal blood vessels
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Genital pores
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Absence of setae
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Parapodia
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.
A biology student has to distinguish the anterior and posterior end of Pheretima morphologically. For it, he can observe/ locate
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Parapodia
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Eyes
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Clitellum
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Tentacles
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.
Which of the following statements is not correct regarding sexuality in organisms?
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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
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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
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In earthworm, both male and female sex organs are present in the same individual and therefore, self-fertilisation occurs in them
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Cockroach is an unisexual animal and exhibit sexual dimorphism
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.
One of the following is wrong about male reproductive organs of earthworm
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Two fluid-filled testis sacs with pair of spermiducal funnel attached to vasa differentia
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Two pairs of seminal vesicles
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Four pairs of spermathecae
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One pair of prostate gland
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All of the above
Larva is not found in the life of
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Pheretima
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Taenia
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Musca
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Rana
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
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Spermatheca
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Testis
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Testis sac
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Seminal vesicle
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?
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Haemadipsa
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Bonellia
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Hirudinaria
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None of the above
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.