In the cloning of cattle, a fertilized egg is taken out of the mother's womb and:
1. | the egg is divided into 4 pairs of cells which are implanted into the womb of other cows |
2. | in the eight-cell stage, cells are separated and cultured until small embryos are formed which are implanted into the womb of other cows |
3. | in the eight-cell stage, the individual cells are separated under an electrical field for further development in cultural media |
4. | from this, up to eight identical twins can be produced |
Which one of the following statements is correct?
1. | Extensive use of chemical fertilizers may lead to eutrophication of nearby water bodies |
2. | Both Azotobacter and Rhizobium in root nodules of plants |
3. | Cyanobacteria such as Anabaena and Nostoc are important mobilizers of phosphates and potassium for plant nutrition in the soil |
4. | At present it is not possible to grow maize without chemical fertilizers |
One of the important consequences of geographical isolation is:
1. no change in the isolated fauna
2. preventing speciation
3. speciation through reproductive isolation
4. random creation of new species
Flagellated male gametes are present in all three of which one of the following sets?
1. Anthoceros, Funaria, and Spirogyra
2. Zygnema, Saprolegnia, and Hydrilla
3. Fucus, Marsilea, and Calotropis
4. Riccia, Dryopteris, and Cycas
Molecular basis of organ differentiation depends on the modulation in transcription by:
1. RNA polymerase
2. ribosome
3. transcription factor
4. anticodon
Increased asthmatic attacks in certain seasons are related to:
1. hot and humid environment
2. eating fruits preserved in tin containers
3. inhalation of seasonal pollen
4. low-temperature
Which of the following is a slime mould?
1. Rhizopus
2. Physarum
3. Thiobacillus
4. Anabaena
Which one of the following is an example of a negative feedback loop in humans?
1. | Constriction of skin blood vessels and contraction of skeletal muscles when it is too cold |
2. | Secretion of tears after falling of sand particles into the eye |
3. | Salivation of the mouth at the sight of delicious food |
4. | secretion of sweat glands and constriction of the skin blood vessels when it is too hot |
Ergot of rye is caused by a species of:
1. Phytophthora
2. Uncinula
3. Ustilago
4. Claviceps
Geometric representation of age structure is a characteristic of:
1. Biotic community
2. Population
3. Landscape
4. Ecosystem