Genetics Answers

1. A cross between a black cat and a tan cat results in a tabby A tabby cat is crossed with a tan cat.

• What is the pattern of inheritance in this example? (1 point)
• What ratio of the offspring will have tabby fur? Tan fur? Black fur? (3 points answer; 4 points Punnett square)

A cross between a blue bird and a white bird produce silver offspring. What are the genotypes of the parents? What are the genotypes of the offspring?

1. Merpeople can be found if you visit Black Lake on the grounds of Hogwarts. Tail colour in merpeople exhibits incomplete dominance. Red tails and white tails are both homozygous traits.

1. Indicate the genotypes for white tails and red tails. (2 marks)
2. What would a mermaid’s tail look like if she was heterozygous for red and white alleles? (1 mark)
3. Use a Punnett square to illustrate the cross between a merman with a white tail and a mermaid that is heterozygous for tail colour. Indicate the phenotypic ratio for their offspring. (3 marks)

A plant that produces white flowers is crossed with a plant that produces purple flowers. 
Briefly explain what Incomplete dominance and Codominance conditions are. (1)
Describe the phenotype of the heterozygous offspring if the inheritance patterns follow an (2)
Incomplete dominance.Codominance.

List several characteristics that eubacteria and archaea have in common and that distinguish them from eukaryotes. 

How are antibiotic-resistance cassettes acquired by integrons? Once acquired, can they be lost?

• When an Hfr bacterial cell transfers its chromo- somal DNA into an F2 recipient cell, where in the chromosome does the transfer process begin? How long does it take to transfer the entire chro- mosome? Why does complete chromosome trans- fer happen only rarely?
• How does the process of transduction differ from that of transformation?

• How are antibiotic-resistance cassettes acquired by integrons? Once acquired, can they be lost?
• What role do antibiotic-resistance genes, trans- posable elements, and transmissible plasmids play in relation to certain pathogenic bacteria that are simultaneously resistant to multiple, chemically unrelated antibiotics?
• How could you distinguish between a bacterial strain that has the phenotype Lac1 and one that has the phenotype Lac2?
• How could you distinguish a Lac1 Amp-r bacterial strain from one that is Lac2 Amp-s? (Amp-r denotes resistance to the antibiotic ampicillin, and Amp-s denotes sensitivity.)
• How does the physical state of the F factor differ between an F1 bacterial cell and an Hfr bacterial cell?
• Is the F1 state of a bacterial cell infectious? Is the Hfr state infectious? Explain why or why not.

n pea plants green pods are dominate to yellow pods if a green pod plant that had a yellow pea pod parent is crossed with a yellow pea pod plant what percentage of the offspring will have green pea pods?

Draw a punnet square that represents the cross between a homozygous mouse with black fur and a homozygous mouse with white fur