Transcript more genetics problems

MORE GENETICS PROBLEMS
Dragons either have forked tongues or they do not. It is a trait determined by
a pair of genes in each dragon (use F and f as genes). If dragons with forked
tongues mate the offspring always have forked tongues. If a dragon without a
forked tongue that was homozygous for the trait mated with a forked tongue
dragon what would be the phenotypic ratio of their offspring?
What would be the genotypic ratios if one of the previous dragon offspring mated
with this one?
If the dragon above had offspring with forked tongues could both of the above
dragon’s parents NOT have forked tongues? Could its mate NOT have a forked
tongue?
Diagram the genotypic relations among the dragon generations from the
previous slide.
Suppose you run a dragon ranch in Rhode Island (Houston metro is bigger than
the entire state!) with plenty of dragons having both kinds of tongue. How could
you determine whether or not your prize male dragon without a forked tongue is
heterozygous?
DIHYBRID GENETICS PROBLEMS
Some dragons have horns as a dominant trait (use H for the dominant gene)
and others are hornless (use h for the recessive gene).
HORNLESS
HORNED
If a hornless dragon WITHOUT a forked tongue mates with a horned forkedtongue dragon and they can produce ONLY some offspring that are horned
with forked tongues and some that are hornless WITHOUT forked tongues
what are the genotypes of the parents?
What would be the genotypic and phenotypic ratios for a cross between the two
kinds of offspring from the preceding slide?
If a horned dragon without a forked tongue that had a parent with a forked tongue and
another parent without horns mates with a horned forked-tongue dragon and they have a
hornless offspring without a forked tongue what are the most probable genotypes of
all the dragons mentioned here?
Red-eyed dragons always produce offspring
with red eyes and white-eyed dragons
always produce offspring with white eyes BUT
a red-eyed dragon and a white-eyed
dragon will always produce offspring with pink
eyes. What would be the genotypic
and phenotypic ratios for the offspring of a
red-eyed dragon and a pink-eyed dragon?
If a pink-eyed hornless dragon mates with a red-eyed horned dragon that had a
hornless parent what would the genotypic and phenotypic ratios of their possible
offspring be?
Dragons have only four colors to their skin (Epidermis): red, black, red-black, and
yellow. Skin color results from a gene locus with three possible alleles: ER, EB, and
e. ER and EB are both dominant to e but not to each other. Yellow skin results from
a homozygous recessive genotype and red-black skin results from genotypes
heterozygous with ER and EB. If a red dragon and a black dragon produce a yellow
dragon what are all their genotypes? What other colors would be possible for
the yellow dragon’s siblings?
If a red female dragon produced a yellow child what color male dragons could
NOT be the father?
A red-black pink-eyed dragon and a yellow white-eyed dragon produce children.
What would be the expected phenotypic and genotypic ratios of those offspring?
Most dragons breathe fire but some cannot, and these latter are mostly males.
Needless to say, this puts a real crimp in their ability to destroy villages and what not!
Lack of
fire-breathing is sex-linked (F=fire and f=no fire). If a fire-breathing male and a firebreathing female that had a father that could not breathe fire (How did he ever find a
fire-breathing mate?!) produce offspring what kinds could they produce?