Which one of the following statements is correct with respect to immunity?
Preformed antibodies need to the injected to treat the bite by a viper snake
The antibodies against small pox pathogen are produced by T-lymphocytes
Antibodies are protein molecules, each of which has four light chains
Antibodies are protein molecules, each of which has four light chains
The figure below shows three steps (A, B, C) of Polymerase Chain Reaction (PCR). Select the option giving correct identification together with what it represents?
B – Denaturation at a temperature of about 98°C separatiing the two DNA strands
A – Denaturation at a temperature of about 50°C
C – Extension in the presence of heat stable DNA polymerase
C – Extension in the presence of heat stable DNA polymerase
The first clinical gene therapy was given for treating
diabetes mellitus
chicken pox
rheumatoid arthritis
rheumatoid arthritis
Which one of the following represents a palindromic sequence in DNA?
5´ - GATACC - 3´
3´ - CCTAAG - 5
5´ - GAATTC - 3
3´ - CTTAAG - 5´
5´- CCAATG - 3´
3´ - GAATCC - 5´
5´- CCAATG - 3´
3´ - GAATCC - 5´
Male gametes are flagellated in
Polysiphonia
Anabaena
Ectocarpus
Ectocarpus
C.
Ectocarpus
Male gametes are flagellated in Ectocarpus belonging to Phaeophyceae. The flagella of male and gamete plays an important role in establishing initial sexual contact with the female gamete. However, in Ectocarpus the female gamete too is flagellated but is different in structure.
In Polysiphonia (Rhodophyceae) flagellated gametes are not observed, in Anabaena sexual reproduction through gametes is absent while in Spirogya sexual reproduction takes place by conjugation wherein male gamete passes through a tube to the adjacent filament. The male gametes here are non-flagellated and show amoeboid movement.
Which one of the following may require pollinators, but is genetically similar to autogamy?
Geitonogamy
Xenogamy
Apogamy
Apogamy
Which one of the following statements is not true?
Pollen grains are rich in nutrients, and they are used in the form of tablets and syrups
Pollen grains of some plants cause severe allergies and bronchial afflictions in some people
The flowers pollinated by flies and bats secrete foul odour to attract them
The flowers pollinated by flies and bats secrete foul odour to attract them