Two Drosophila with genotypes AABBCC and aabbcc are crossed to produce a heterozygous offspring, AaBbCc (the gene order is unknown). This AaBbCc Drosophila is crossed with an aabbcc Drosophila, resulting in the offspring below: Number: Phenotype: 600 ABC and abc 200 AbC and aBc 150 ABc and abC 50 Abc and aBC a. Which phenotype represents the double crossovers

The double recombinant individuals are less frequent ---> Abc and aBC

Explanation:

We can know if genes are linked, by looking at the progeny distribution. In a tri-hybrid cross, If individuals, whose genes assort independently, are test crossed, they produce a progeny with equal phenotypic frequencies 1:1:1:1:1:1:1:1. If we observe a different distribution, meaning that phenotypes appear in different proportions, we can assume that genes are linked in the heterozygote parent.

We can recognize the parental gametes because their phenotypes are the most frequent in the descendants, while the double recombinants are the less frequent. Finally, the simple recombinant gametes are the ones with intermediate phenotypes frequencies.  

In the present example, the phenotypic ratio shows different proportions than the expected ones if they were not linked.

We can recognize the parental gametes in the descendants because their phenotypes are the most frequent,

while the double recombinants are less frequent.

And simple recombinant gametes produced by the cross, which frequencies are intermediate.  

a. Which phenotype represents the double crossovers

The double recombinants are less frequent ---> Abc and aBC

water is a polar molecule. a chemical bond is a force of attraction between atoms or ions. bonds form when atoms share or transfer valence electrons. atoms form chemical bonds to achieve a full outer energy level, which is the most stable arrangement of electrons. so, false

explanation:

in h2o molecule, two water molecules are bonded by a hydrogen bond but the bond between two h - o bonds within a water molecule are covalent. the greater the electronegativity difference, the more ionic the bond is. bonds that are partly ionic are called polar covalent bonds. nonpolar covalent bonds, with equal sharing of the bond electrons, arise when the electronegativities of the two atoms are equal.