Answer: D) All the above Explanation: Random mutations are the ultimate source of genetic variation. Mutations are likely to be rare and most mutations are neutral or deleterious, but in some instances, the new alleles can be favored by natural selection. Polyploidy is an example of chromosomal mutation.   Mutations are changes in the DNA. A single mutation can have a large effect. 1) mutation - an alteration in DNA sequence, various types 2) intragenic recombination - results in entirely new associations of genes not present in either parental genome. Two forms of intragenic recombination: a) crossing overb) independent assortment3) reticulation – acquisition of genetic material from unrelated or relatively unrelated sources (e.g., hybrid species, horizontal gene transfer).

Answer: C) 48 lit Explanation: Let the amount of juice and water in original mixture '4x' litre and '3x' litre respectively. According to given data, 4x/3x+6 =8/7 28x=24x+48 28x–24x=48 4x = 48 x = 12 Amount of juice = 4x = 4×12 = 48 litre.

Answer: A) 400 m Explanation: Speed = 78 x 5/18 = 65/3 m/sec.Time = 1 min = 60 sec.Let the length of the train be x meters.Then, (900 + x)/60 = 65/3x = 400 m.

Answer: A) Violet Explanation: In VIBGYOR. It has colors ordered from highest to lowest frequency.                 Violet > Indigo > Blue > Green > Yellow > Orange > Red   That says Violet has the highest frequency. We know, Speed of light = Frequency x Wavelength => As frequeny is inversely proportional to wavelength i.e, as frequwncy goes high wavelength goes down.   So, the violet color has the highest frequency.

Answer: D) 18.75 % Explanation: Given,S.I = 3 Principal Amount=> 3A = A x 16 x R/100By solving, we get => R = 18.75%

Answer: A) 2648 Explanation: 8000 × 33.1% = 2648

Answer: C) 9 Explanation: The mother completes the job in x hours.So, the daughter will take 2x hours to complete the same job.   In an hour, the mother will complete 1/x of the total job.In an hour, the daughter will complete 1/2x of the total job.   So, if the mother and daughter work together, in an hour they will complete 1/x + 1/2x of the job.i.e., in an hour they will complete 3/2x of the job.   The question states that they complete the entire task in 6 hours if they work together.i.e., they complete 1/6 th of the task in an hour.   Equating the two information, we get 3/2x = 1/6By solving for x, we get 2x = 18 or x = 9.   The mother takes 9 hours to complete the job.

Answer: C) 7 days Explanation: 1 boy's 1 day work = 1/70 1 girl's 1 day work = 1/140 (5 boys + 10 girls)'s 1 day work = (5/70 + 10/140) = (1/14 + 1/14) = 1/7   5 boys and 10 girls will complete the work in 7 days.