Two experimental varieties of strawberry are produced by...

Question

Two experimental varieties of strawberry are produced by crossing a hexaploid line that contains 48 chromosomes and a tetraploid line that contains 32 chromosomes. Experimental variety 1 contains 40 chromosomes, and experimental variety 2 contains 56 chromosomes.

How many chromosomes from the hexaploid line are contributed to experimental variety 1? To experimental variety 2?

Accepted Answer

Hi, everyone. Let's take a look at this practice problem together. A variety of potato is produced with 60 chromosomes by crossing a tetraploid line with 48 chromosomes with a hex aloed line that contains 72 chromosomes determine the number of chromosomes contributed by the tetraploid line. The answer options are a 12 b 24 C 36 D 48. So let's use a picture to help us work through this problem. I like to visualize things. So the picture is on the screen, it represents the tetraploid and hex Sulo lines producing gametes that ultimately produce that 60 chromosome potato variety and circles represent cells. So on the left is the tetraploid line. The tetraploid cell produces the te which is drawn below it. On the right is the hexapod line. The hex aloed cell produces a gam which is also depicted bef below it. And then those two gas combined to produce the 60 chromosome potato variety. Now recall in genetics that the letter N is used to represent the number of chromosomes in a single set. So in the tetraploid line, a tetraploid cell would have four sets of chromosomes. So we would write that as four N and we know from the question that it has 48 chromosomes total. So in the tetraploid cell, we have written four N equals 48 the gamma produced from this cell would contain half the amount of chromosomes. So inside the tetraploid gammit cell, I will write two and equals 24. Now let's figure out the hex aid line, hex means six. So inside the hexapod cell, we would have six N equals 72 chromosomes in the Hexapod line, the gammy it produces with, therefore, we would represent it as three N equals 36. So 24 chromosomes from the tetraploid line and chromosomes from the hex upload line combined to make that chromosome cell. So what is the number of chromosomes contributed by the tetraploid line that is going to be 24? So the correct answer is option B 24. All right, everyone. I hope you found this helpful and I'll see you soon for the next practice problem.

Key Concepts

Chromosome Number and Ploidy

Genetic Contribution in Hybridization

Chromosome Segregation

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