In drosophila, the genes crossveinless and stubble are linked, about 7 map units apart on chromosome 3. cv is a recessive mutant allele of crossveinless (cv+ is wild type), while sb is a dominant mutant allele of stubble (sb+ is wild type). a dihybrid female drosophila with genotype cv sb+/cv+ sb is testcrossed. the proportion of phenotypically wild-type individuals in the progeny of the testcross will be

0.035

Explanation:

cv+ is the wild-type dominant allele over cv, therefore:

Sb is a dominant mutant allele over wild-type Sb+, therefore:

It's the cross between the heterozygous female with a homozygous recessive male. Remember that cv and Sb+ are the recessive alleles.

 X

-The male produces only 1 type of gamete: cv Sb+

-The female produces 4 types of gametes:

The genes are linked and separated by 7 map units. A distance of 7 mu means that 7% of the resulting gametes will be recombinant. Because there are 2 possible recombinant gametes, each of them will appear in 3.5% of the cases.

The genotypes and proportions of the offspring resulting from the test cross can be seen in the Punnett Square. The phenotypically wild-type individuals will have the genotype cv+ Sb+ / cv Sb+ (heterozygous for crossveinless and homozygous recessive for Stubble) and a 0.035 proportion.

one is through turgidity. this occurs before ground tissue ( collenchyma

and sclerenchyma cells) become well

developed to give structural support to the plant as it grows bigger. the xylem

tissue (composed of rigid tissue) of the young

plant render this support and also maintaining osmotic turgidity of the surrounding

plant cells.