The body weight of offspring of bird species is range between 12 gm to 18 gm. In a laboratory experiment, species was subjected to selection pressure having influence on the offspring body weight. After many generations of experimental selection pressure, the body weight range between 14 gm to 16 gm. Which of the following natural selection operate on this species?

#Question id: 3266

#Section 2: Evolution

One species mates at the season when daylight is increasing from 13 hours to 13 hours, 15 minutes; another species mates at the season when daylight is increasing from 14 hours to 14 hours, 15 minutes. The isolating mechanism is

#Question id: 3267

#Section 2: Evolution

In a typical Mendelian population, individuals carrying gene ‘a’ in homozygous condition suffer from phenylketonurea. Those with A in homozygous condition are normal. Others, who are heterozygotic with Aa, are carriers. If the frequency of ‘a’ in a population is 0.20, what is the percentage of normal individual in the population?

#Question id: 3268

#Section 2: Evolution

A population of insects is in Hardy-Weinberg equilibrium for a gene with alleles A = orange and a = yellow eyes. There are 91% orange and 9% yellow individuals in the population. If the fitness of the yellow phenotype suddenly drops to zero, what will be the allele frequency in the next generation?

#Question id: 4721

#Section 2: Evolution

PKU, results from a recessive allele; persons homozygous for this allele, if untreated, exhibit mental retardation, blue eyes, and light skin color. This character categorized as

#Question id: 3269

#Section 2: Evolution

Two plant species live in the same biome but on different continents. Although the two species are not at all closely related, they may appear quite similar as a result of

#Question id: 4723

#Section 2: Evolution

The most common cause of the pleiotropic effect of gene is due to