Posted by grad2013 on Tuesday, April 2, 2013 at 9:11am.
You are studying genetics in domestic chickens (Gallus gallus) and you find a mutant with no wings. Assume that the mutant wingless phenotype is due to a mutation at a single gene.
In contrast to mammals, chickens use ZZ/ZW sex-linkage. That is, male chickens have two copies of the sex chromosome, the Z chromosome, while females have one copy of Z and one copy of W. The W is like the Y in mammals; it carries very few genes.
You should use the following symbols in this problem:
• If the gene is autosomal, use:
• “A” for the allele with the dominant phenotype
• “a” for the allele with the recessive phenotype
• If the gene is sex-linked (Z-linked) use:
• “ZA” for the allele with the dominant phenotype
• “Za” for the allele with the recessive phenotype
• “W” for the W-chromosome:
• b) You cross an F1 male to an F1 female (both phenotypically normal-winged). In their 400 offspring, you see a 3:1 ratio of normal to wingless. Upon closer examination, you find that all the wingless chickens are female. Based on these data:
• i) Is the wingless gene autosomal or Z-linked?
• ii) What is the genotype of the normal-winged F1 male parent of the cross? (AA, Aa, aa, A_, ZAZA, ZAZa, ZaZa, ZAZ, ZAW, or ZaW)
• iii) What is the genotype of the normal-winged F1 female parent of the cross? (AA, Aa, aa, A_, ZAZA, ZAZa, ZaZa, ZAZ, ZAW, or ZaW)
• iv) What is the genotype of the wingless female offspring of the cross? (AA, Aa, aa, A_, ZAZA, ZAZa, ZaZa, ZAZ, ZAW, or ZaW).
- science - grad2013, Tuesday, April 2, 2013 at 4:45pm
• a) You cross a pure breeding male with normal wings to a pure breeding wingless female. All of the F1 offspring have normal wings. Based on this result, which of the following statements is true:
a-) Therefore Cross of Parent AA X aa or ZAZA X ZaW therefore
The normal wing phenotype is dominant; the wingless phenotype is recessive.
Please help me with part b?
Answer This Question
More Related Questions
- Genetics part b only - You are studying genetics in domestic chickens (Gallus ...
- Genetics - A pepper plant is heterozygous for a mutant allele of the gene ...
- biology - Alcanivorax is a naturally occurring oil-degrading marine bacterium ...
- Biology - ystic fibrosis is caused by mutations in the CFTR gene, which encodes ...
- biochemical genetics - After several rounds of experiments like those described ...
- genetics - I PCR out a mutated gene in a patient with Lisenbee chorea (the ...
- biology - For each of these restriction enzymes, determine whether or not the ...
- science - If a single gen controls the mutant trait, how will you determine the ...
- biology - If you have a gene pathway with three activities, say A, B and C, and ...
- microbiology - Rifampin inhibits the â subunit of the E. coli RNA polymerase. A ...