At one gene locus in humans there are 2 alleles: one for curly hair and another for straight hair. neither allele is dominant, and heterozygous individuals have wavy hair. at a second gene locus, 3 alleles control abo blood type. the alleles at these 2 gene loci assort independently. a man with straight hair and a blood has children with a woman with wavy hair and b blood. their first child has straight hair and o blood. if their second child is a boy with straight hair, what is the probability that he has a blood? ( express your answer as a percentage. enter the number only without the percent sign. for example, enter 100% as 100 and enter 12.5% as 12.5 )

25%

Explanation:

Genotypes and phenotypes:

A man with straight hair and A blood has the genotype SS AA or SS A0.

A woman with wavy hair and B blood has the genotype SC BB or SC B0.

Their first child has straight hair and O blood: SS 00

Because the child has type 0 blood, both parents must have a 0 allele, so their genotypes are SS A0 and SC B0.

If their second child is a boy with straight hair, what is the probability that he has A blood?

The hair and blood type genes are independent, so the hair phenotype of the child is irrelevant to determine the probability of him having A blood.

The parental cross for blood type is A0 x B0.

If you do a Punnett Square, you'll get the following offspring:

25% AB, 25% B0, 25% A0 and 25% 00.

The answer is the child has a probability of 25% of having A blood.

from my research i have to the conclusion that decomposers, such as fungi, bacteria and invertebrates, play a critical role in nutrient cycling and without them the earth's ecosystem may not support life as we know it. elements such as carbon, nitrogen and phosphorus exist in limited amounts on earth, although huge amounts of carbon are being released into the atmosphere from underground sources now by humans. it is still extremely important that other nutrients be retained by the process of re-use. decomposers are organisms that are able to chemically break down dead material and make these elements available for use by other organisms. without this breakdown of dead material, dead bodies would pile up. so decomposers also play a role in clean up also. without them, life might not continue as we know it and dead material would overwhelm the earth.