Two genes of a flower, one controlling blue (B) versus white (b) petals and the other controlling round (R) versus oval (r) stamens, are linked and are 10 map units apart. You cross a homozygous blue oval plant with a homozygous white round plant. The resulting F1 progeny are crossed with homozygous white oval plants, and 1,000 offspring plants are obtained. How many plants of each of the four phenotypes do you expect?

Video transcript

Hello everyone here we have a question telling us to genes of a flower are linked and are 20 mac units apart. One gene controls height capital T. Equals tall versus lower case T. Equals dwarf and the other controls the flower color capital B. Equals P. Equals purple versus lower case P. Equals white crossing. Homo zegas tall plant with white flour with a homogeneous door plant with purple flower. And the resulting F. One progeny is crossed with homo zegas dwarf plants with white flowers. If the F two progeny has 100 plants which of the following correctly shows the number of plants of each four phenotype sis So our parents are going to be capital T. Capital T. Lowercase P. Lowercase P. And lower case T. Lowercase T. Capital P. Capital P. So let's make a punnett square. So we have lower case T. Lowercase P. Lower case T. Lowercase P. Lower case T. Lowercase P. Lower case T. Lowercase P. And we're going to have capital T. Capital P. Capital T. Lowercase P. Lower case T capital P. Lower case T. Lower case P. So that will give us capital T. Lowercase T. Capital P. Lowercase P. Capital T. Lowercase T. Capital P. Lowercase P. Capital T. Lowercase T. Capital P. Lowercase P. Capital T capital lower case T. Capital P. Lowercase P capital T. Lowercase T. Lowercase P. Lowercase P capital T. Lowercase T. Lowercase P. Lowercase P. Capital T. Lowercase T. Lowercase P. Lowercase P. Capital T. Lowercase T. Lowercase P. Lowercase P. Lower case T. Lowercase T capital P. Lowercase P. Lower case T. Lowercase T. Capital P. Lowercase P. Lower case. T. Lowercase T. Capital P. Lowercase P. Lower case. T. Lowercase T. Capital P. Lowercase P. Lower case. T. Lowercase T. Lowercase P. Lowercase P. Lower case. T. Lowercase T. Lowercase P. Lowercase P. Lower case. T. Lowercase T. Lowercase P. Lowercase P. Lower case T. Lowercase T. Lowercase P. Lowercase P. So as we can see we have four of each so our ratio is one To 1-1. So our genes are 20 map units apart which means that 20% will be re cominin and 80% will be parental. So we're going to take 20 Divided by 100 Because we have plants overall and 20% is going to be competent and then we're gonna multiply by 100 And that equals 20 plants. So 20 plants are going to be re competent. And since the ratio is 1-1 our capital T. Lowercase T. Lowercase P. Lowercase P. Will be 10 and lower case T. Lowercase T. Capital P. Lower case P. Will also be 10. So we will have parental will be 80 plants. So our parental capital T capital T. Lowercase P. Lowercase P. Will be 40 and the other half will be lower case T. Lowercase T. Lowercase P. Lowercase P which equals 40. So our answer here is C. Tall. Purple 40 tall. White tin dwarf purple tin dwarf white 40. Thank you for watching. Bye