Advertisements
Advertisements
प्रश्न
State and explain any three factors affecting allele frequency in populations.
Advertisements
उत्तर
- Gene migration or gene flow: When migration of a section of population to another place and population occurs, gene frequencies change in the original as well as in the new population. New genes/alleles are added to the new population and these are lost from the old population. There would be a gene flow if this gene migration happens multiple times.
- Genetic drift: If the same change occurs by chance, it is called genetic drift. Sometimes the change in allele frequency is so different in the new sample of the population that they become a different species. The original drifted population becomes founders and the effect is called founder effect.
- Mutation: Microbial experiments show that pre-existing advantageous mutations when selected will result in the observation of new phenotypes. Over a few generations, this would result in speciation. Natural selection is a process in which heritable variations enabling better survival are enabled to reproduce and leave greater number of progeny.
APPEARS IN
संबंधित प्रश्न
With the help of an algebraic equation, how did Hardy-Weinberg explain that in a given population the frequency of occurrence of alleles of a gene is supposed to remain the same through generations?
Differentiate between Directional natural selection and Disruptive natural selection.
What is the Founder's effect?
How does the Hardy-Wienberg equation explain genetic equilibrium?
Multiple choice question.
In Hardy - Weinberg equation, the frequency of homozygous recessive individual is represented by:
A population will not exist in Hardly Weiberg equilibrium if ____________.
How does Hardy-Weinberg’s expression (p2+2pq+q2=1) explain that genetic equilibrium is maintained in a population? List any four factors that can disturb the genetic equilibrium.
In the Hardy-Weinberg equilibrium equation, the homozygous mutant is represented as ______.
The factor that leads to the Founder effect in a population is ______
For the MN-blood group system, the frequencies of M and N alleles are 0.7 and 0.3, respectively. The expected frequency of MN-blood group bearing organisms is likely to be ______.
In a certain population, the frequency of three genotypes is as follows:
| Genotypes: | BB | Bb | bb |
| frequency: | 22% | 62% | 16% |
What is the likely frequency of B and b alleles?
Among the five factors that are known to affect Hardy-Weinberg equilibrium, three factors are gene flow, genetic drift and genetic recombination. What are the other two factors?
Enumerate three most characteristic criteria for designating a Mendelian population.
“Migration may enhance or blurr the effects of selection”. Comment.
List any two factors that can disturb the genetic equilibrium.
At a particular locus, the frequency of allele A is 0.8, and that of allele a is 0.2. What would be the frequency of heterozygotes in a random mating population at equilibrium?
Write Hardy Weinberg's equation.
A population of 200 fruit flies is in Hardy Weinberg equilibrium. The frequency of the allele (a) 0.4. Calculate the following:
The number of homozygous recessive fruit flies.
The black colour on the beak of finches dominates over the yellow colour. There are 210 individuals with the genotype DD, 245 individuals with the genotype Dd and 45 individuals with the genotype dd. Deduce the frequency of individuals with dominant, heterozygous, and recessive traits.
