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| # | Question | Subject and topic | Difficulty |
|---|---|---|---|
| 1551 | Meselson and Stahl separated DNA of different densities using | Biology/Biological Studies/Biotechnology/Biochemistry DNA replication |
Easy |
| 1552 | In the Meselson–Stahl experiment, what was observed after one generation in ¹⁴N medium? | Biology/Biological Studies/Biotechnology/Biochemistry DNA replication |
Medium |
| 1553 | Why is DNA synthesis continuous on one strand but discontinuous on the other? | Biology/Biological Studies/Biotechnology/Biochemistry DNA replication |
Medium |
| 1554 | E. coli cells with fully ¹⁵N-labelled DNA are grown in ¹⁴N medium for three generations. What fraction of DNA… | Biology/Biological Studies/Biotechnology/Biochemistry DNA replication |
Hard |
| 1555 | In eukaryotes, which RNA polymerase transcribes the precursor of mRNA (hnRNA)? | Biology/Biological Studies/Biotechnology/Biochemistry Transcription |
Easy |
| 1556 | The removal of introns and joining of exons in hnRNA is called | Biology/Biological Studies/Biotechnology/Biochemistry Transcription |
Easy |
| 1557 | The coding strand of a gene reads 5′-ATGCCA-3′. What will be the sequence of the RNA transcribed from it? | Biology/Biological Studies/Biotechnology/Biochemistry Transcription |
Medium |
| 1558 | In bacteria, which factor helps RNA polymerase to terminate transcription? | Biology/Biological Studies/Biotechnology/Biochemistry Transcription |
Medium |
| 1559 | Why can translation begin before transcription is complete in bacteria but not in eukaryotes? | Biology/Biological Studies/Biotechnology/Biochemistry Transcription |
Hard |
| 1560 | Which codon acts as the start codon and also codes for methionine? | Biology/Biological Studies/Biotechnology/Biochemistry Genetic code and translation |
Easy |
| 1561 | The fact that some amino acids are coded by more than one codon shows that the genetic code is | Biology/Biological Studies/Biotechnology/Biochemistry Genetic code and translation |
Easy |
| 1562 | Which part of a tRNA recognises the codon on mRNA? | Biology/Biological Studies/Biotechnology/Biochemistry Genetic code and translation |
Medium |
| 1563 | The coding region of an mRNA, from the start codon AUG to the stop codon (both included), has 300 nucleotides… | Biology/Biological Studies/Biotechnology/Biochemistry Genetic code and translation |
Medium |
| 1564 | In bacteria, which molecule catalyses peptide bond formation during translation? | Biology/Biological Studies/Biotechnology/Biochemistry Genetic code and translation |
Hard |
| 1565 | In the lac operon, which gene codes for β-galactosidase? | Biology/Biological Studies/Biotechnology/Biochemistry Regulation of gene expression |
Easy |
| 1566 | What is the role of lactose in the lac operon? | Biology/Biological Studies/Biotechnology/Biochemistry Regulation of gene expression |
Easy |
| 1567 | In the absence of lactose, the lac operon is switched off because | Biology/Biological Studies/Biotechnology/Biochemistry Regulation of gene expression |
Medium |
| 1568 | Regulation of the lac operon by the repressor is an example of | Biology/Biological Studies/Biotechnology/Biochemistry Regulation of gene expression |
Medium |
| 1569 | A mutant E. coli has a repressor that cannot bind lactose but can still bind the operator. What will happen w… | Biology/Biological Studies/Biotechnology/Biochemistry Regulation of gene expression |
Hard |
| 1570 | In which year was the Human Genome Project completed? | Biology/Biological Studies/Biotechnology/Biochemistry Human Genome Project and DNA fingerprinting |
Easy |
| 1571 | Which human chromosome was found to have the fewest genes? | Biology/Biological Studies/Biotechnology/Biochemistry Human Genome Project and DNA fingerprinting |
Easy |
| 1572 | The probe used by Alec Jeffreys for DNA fingerprinting was based on | Biology/Biological Studies/Biotechnology/Biochemistry Human Genome Project and DNA fingerprinting |
Medium |
| 1573 | What is the correct order of steps in DNA fingerprinting? | Biology/Biological Studies/Biotechnology/Biochemistry Human Genome Project and DNA fingerprinting |
Medium |
| 1574 | Why can DNA fingerprinting distinguish between two individuals even though 99.9% of their bases are identical? | Biology/Biological Studies/Biotechnology/Biochemistry Human Genome Project and DNA fingerprinting |
Hard |
| 1575 | Which scientist disproved spontaneous generation using pre-sterilised flasks? | Biology/Biological Studies/Biotechnology/Biochemistry Origin of life |
Easy |
| 1576 | Which gases did Miller use in his experiment along with water vapour? | Biology/Biological Studies/Biotechnology/Biochemistry Origin of life |
Easy |
| 1577 | What was the main product detected in Miller's original experiment? | Biology/Biological Studies/Biotechnology/Biochemistry Origin of life |
Medium |
| 1578 | Oparin and Haldane proposed that the first life was preceded by | Biology/Biological Studies/Biotechnology/Biochemistry Origin of life |
Medium |
| 1579 | Why was the early Earth's atmosphere important for Miller's results? | Biology/Biological Studies/Biotechnology/Biochemistry Origin of life |
Hard |
| 1580 | The forelimbs of a whale, a bat and a human are examples of | Biology/Biological Studies/Biotechnology/Biochemistry Evidence for evolution |
Easy |
| 1581 | The wings of a butterfly and of a bird are | Biology/Biological Studies/Biotechnology/Biochemistry Evidence for evolution |
Easy |
| 1582 | The thorn of Bougainvillea and the tendril of Cucurbita illustrate | Biology/Biological Studies/Biotechnology/Biochemistry Evidence for evolution |
Medium |
| 1583 | In industrial areas of England, dark moths became more common after 1850 mainly because | Biology/Biological Studies/Biotechnology/Biochemistry Evidence for evolution |
Medium |
| 1584 | Which pair shows convergent evolution? | Biology/Biological Studies/Biotechnology/Biochemistry Evidence for evolution |
Hard |
| 1585 | According to Darwin, the fitness of an individual ultimately refers to its | Biology/Biological Studies/Biotechnology/Biochemistry Darwin and natural selection |
Easy |
| 1586 | Darwin's finches of the Galapagos Islands are an example of | Biology/Biological Studies/Biotechnology/Biochemistry Darwin and natural selection |
Easy |
| 1587 | Which naturalist independently reached conclusions similar to Darwin's while working in the Malay Archipelago? | Biology/Biological Studies/Biotechnology/Biochemistry Darwin and natural selection |
Medium |
| 1588 | Lamarck suggested that the giraffe's long neck arose because ancestors stretched to reach leaves and passed o… | Biology/Biological Studies/Biotechnology/Biochemistry Darwin and natural selection |
Medium |
| 1589 | The Tasmanian wolf (a marsupial) and the placental wolf look similar. This similarity is best explained by | Biology/Biological Studies/Biotechnology/Biochemistry Darwin and natural selection |
Hard |
| 1590 | Hugo de Vries based his mutation theory on studies of | Biology/Biological Studies/Biotechnology/Biochemistry Mechanisms of evolution |
Easy |
| 1591 | A random change in allele frequency in a small population is called | Biology/Biological Studies/Biotechnology/Biochemistry Mechanisms of evolution |
Easy |
| 1592 | A small group of birds is blown to an island and starts a new population whose allele frequencies differ from… | Biology/Biological Studies/Biotechnology/Biochemistry Mechanisms of evolution |
Medium |
| 1593 | In a bird population, both very small and very large beaks become common while medium beaks become rare. This… | Biology/Biological Studies/Biotechnology/Biochemistry Mechanisms of evolution |
Medium |
| 1594 | How do de Vries's mutations differ from the variations Darwin described? | Biology/Biological Studies/Biotechnology/Biochemistry Mechanisms of evolution |
Hard |
| 1595 | According to the Hardy–Weinberg equation, the frequency of heterozygotes is given by | Biology/Biological Studies/Biotechnology/Biochemistry Hardy-Weinberg principle |
Easy |
| 1596 | Which of the following does not disturb Hardy–Weinberg equilibrium? | Biology/Biological Studies/Biotechnology/Biochemistry Hardy-Weinberg principle |
Easy |
| 1597 | In a population at equilibrium, 16% of individuals show a recessive trait. What is the frequency of the domin… | Biology/Biological Studies/Biotechnology/Biochemistry Hardy-Weinberg principle |
Medium |
| 1598 | If the frequency of allele A is 0.7 in a population at equilibrium, what is the expected frequency of genotyp… | Biology/Biological Studies/Biotechnology/Biochemistry Hardy-Weinberg principle |
Medium |
| 1599 | In a population of 1000 at Hardy–Weinberg equilibrium, 160 individuals are homozygous recessive. How many are… | Biology/Biological Studies/Biotechnology/Biochemistry Hardy-Weinberg principle |
Hard |
| 1600 | Which fish, thought to be extinct, was caught in South Africa in 1938? | Biology/Biological Studies/Biotechnology/Biochemistry History of life and human evolution |
Easy |