Mendelian Genetics & Inheritance Patterns Free Response - - PDF document

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Mendelian Genetics & Inheritance Patterns Free Response

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1 The results of Mendel’s experiments allowed him to develop four (4) hypotheses regarding

• inheritance. Although we have added greatly to

this knowledge, his understandings still hold true. Explain each hypothesis in 1-2 sentences.

A Hypothesis #1: Alleles. B

Hypothesis #2: Two alleles.

C

Hypothesis #3: Dominant and recessive

D

Hypothesis #4: Law of Segregation

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2 Two mice heterozygous for the long tail gene are crossed (P generation). Let T = long tail and t = short tail. These mice have 18 offspring, some which have long tails and some that have short tails.

A Draw a Punnett Square illustrating the cross of the

parental generation)

B We want to select out the mice with long tails, but only the

• nes with the genotype of TT. Which mice will you cross?

C What possible results will you get from your cross? (show

your Punnett square(s)).

D What result do we get if we have a true breeding long

tailed mouse?

E What do we call this type of experimental crossing?

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3 Two dihybrid plants are crossed. Let R = allele for red flowers; r = allele for white flowers; T = allele for tall plants; t = allele for short plants. The inheritance of these alleles exhibits complete dominance.

A What is the probability for offspring that are RRTT: (show

all work)

B What is the probability for offspring that are RrTt: (show all

work)

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4 Two trihybrid plants are crossed. Let R = allele for red flowers; r = allele for white flowers; T = allele for tall plants; t = allele for short plants; B = big flowers; b = small flowers. The inheritance of these alleles exhibits complete dominance.

A What is the probability for offspring that are RRTTBb:

(show all work)

B What is the probability for offspring that are RrTTBB:

(show all work)

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5 Male patterned baldness cannot be determined by

• bserving the hair pattern of a man’s father. This

is because this trait is a recessive sex-linked trait. Using the letter B to represent the not bald allele and b to represent baldness, allele respond to the prompts below

A

Because this is a sex-linked trait, what will be the symbol you will use for a female who is a carrier for male patterned baldness?

B Because this is a sex-linked trait, what will be the symbols

you will use for a male who is not bald?

C Show the cross between such a female and a male, using

a Punnett square.

D What is the percent probability that this couple will have a

child with male patterned baldness?

E What is the percent probability that, given they have a

male child, the child will have male patterned baldness.

F What is the percent probability that, given they have a

female child, the child will have male patterned baldness.

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6 A pedigree is shown below. Refer to this pedigree to respond to the prompts below.

A Is the X-linked trait indicated by the darkened circles and

squares, dominant or recessive?

B

For each individual within the pedigree (1-15) write in the line below the genotype (don’t forget the Xs). Use the letters B and b to indicate the allele. (there are two possibilities for individuals 10 and 12)

C

For the man labeled as #11 above, if he has children with a woman who does not exhibit the x-linked trait, what is the percent probability they will have a child who will exhibit the trait?

D

For the man labeled as #11 above, if he has children with a woman who does exhibit the x-linked trait, what is the percent probability they will have a child who will exhibit the trait?

https://migrc.org/Library/Sexlinked

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