Using imprints from a plate with complete medium and carrying bacterial colonies, you can select streptomycin resistant mutants and prove that such mutations do not originate as adaptation. These imprints need to be used :
- only on plates with streptomycin
- on plates with minimal medium
- only on plates without streptomycin
- on plates with and without streptomycin
The Correct Option is A
Solution and Explanation
Plates containing streptomycin enable the growth and proliferation of only those bacteria that possess resistance to the antibiotic.
So, the correct option is (A): only on plates with streptomycin
Top Questions on evolution
- Sweet potato and potato represent a certain type of evolution. Select the correct combination of terms to explain the evolution.
- NEET (UG) - 2025
- Biology
- evolution
- Read the following passage and answer the questions that follow.
According to evolutionary theory, every evolutionary change involves the substitution of a new gene for the old one and the new allele arises from the old one. Continuous accumulation of changes in the DNA coding for proteins leads to evolutionary differences. The chemical composition of DNA is basically the same in all living beings, except for differences in the sequence of nitrogenous bases. Given below are percentage relative similarities between human DNA and DNA of other vertebrates:
- Land reptiles which went back into water about 200 mya to evolve into fish-like reptiles were :
- If a natural population with 200 individuals is in Hardy-Weinberg equilibrium for a gene with two alleles A and a, and with the gene frequency of allele A of 0.8, the genotype frequency of Aa will be :
- The animals that evolved into the first amphibians during evolutionary history were:
Questions Asked in NEET exam
- Given below are two statements:
Statement I: Fig fruit is a non-vegetarian fruit as it has enclosed fig wasps in it.
Statement II: Fig wasp and fig tree exhibit a mutual relationship as the fig wasp completes its life cycle in the fig fruit and the fig fruit gets pollinated by the fig wasp. - An oxygen cylinder of volume 30 litre has 18.20 moles of oxygen. After some oxygen is withdrawn from the cylinder, its gauge pressure drops to 11 atmospheric pressure at temperature \(27^\circ\)C. The mass of the oxygen withdrawn from the cylinder is nearly equal to: [Given, \(R = \frac{100}{12} \text{ J mol}^{-1} \text{K}^{-1}\), and molecular mass of \(O_2 = 32 \text{ g/mol}\), 1 atm pressure = \(1.01 \times 10^5 \text{ N/m}^2\)]
- NEET (UG) - 2025
- Ideal-gas equation and absolute temperature
- A wire of resistance \(R\) is cut into 8 equal pieces. From these pieces, two equivalent resistances are made by adding four of these together in parallel. Then these two are added in series. The net effective resistance of the combination is:
- NEET (UG) - 2025
- Resistance
The current passing through the battery in the given circuit, is:
- NEET (UG) - 2025
- Current electricity
Three identical heat conducting rods are connected in series as shown in the figure. The rods on the sides have thermal conductivity 2K while that in the middle has thermal conductivity K. The left end of the combination is maintained at temperature 3T and the right end at T. The rods are thermally insulated from outside. In steady state, temperature at the left junction is \(T_1\) and that at the right junction is \(T_2\). The ratio \(T_1 / T_2\) is
- NEET (UG) - 2025
- Conductivity-thermal and electrical
Concepts Used:
Evolution
Evolution is a process that occurs in changes in the genetic content of a population over time. Evolutionary change is generally classified into two: microevolution and macroevolution. The process of changes in allele frequencies in a population over time is a microevolutionary process. Three main mechanisms that cause allele frequency change are natural selection, genetic drift, and gene flow. On the other hand, macroevolution refers to change at or above the level of the species.