Multiple Choice Questions

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Which extraembryonic membrane in humans prevents desiccation of the embryo inside the uterus?

  • Chorion

  • Allantois

  • Yolk sac

  • Amnion


D.

Amnion

Amnion is an extraembryonic membrane that surrounds embryo in reptiles, birds and mammals. It provides a kind of private aquarium to the embryo and protects it from mechanical shock and desiccation.

Chorion (serosa) is the outermost extra - embryonic membrane in reptiles, birds and mammals. It surrounds the whole embryonic system of the embryo.

Yolk sac contains yolk in reptiles and birds. In mammals, the yolk sac is also known as an umbilical vesicle. It is connected to enter one of the embryo by a slender yolk stalk. Allantois functions as an embryonic urinary bladder or as a respiratory extension of hindgut in reptiles and birds. In mammals, it is modified to carry blood vessels to and from the placenta.


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Which of the following is a total root parasite?

  • Cuscuta

  • Rafflesia

  • Santalum

  • Monotrapa


AIDS virus contains

  • RNA with protein

  • DNA with protein

  • DNA without protein

  • bNA only


When pollen tube enters through micropyle, the process is called

  • Porogamy

  • Chalazogamy

  • Mesogarny

  • Apogamy


A transgenic food crop, which may help in solving the problem of nightblindness in developing countries is

  • Flavr savr tomatoes

  • Starlink maize

  • Bt soyabean

  • Golden rice


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Outer wall of pollen grain is made up of

  • Cellulose

  • Sporopollenin

  • Pectocellulose

  • Lignin


Cells obtained from cancerous tumours are known as

  • Hybridomas

  • Myelomas

  • Lymphocytes

  • Monoclonal cells


Polyploidy can be induced by the application of

  • Auxin

  • Kinetin

  • Colchicine

  • Ethylene


Which of the following bio-engineered bacteria is utilized for cleaning of marine oil slicks?

  • Escherichia coli

  • Pseudomonas syringae

  • Pseudomonas putida

  • Rhizoctonia solani


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DNA replication occurs in

  • G1-phase

  • S-phase

  • G2-phase

  • M-phase