Genetics Homozygous quiz questions

1. This disease is lethal and strikes early in childhood.

True

False

Since parents pass it on to their offspring, it is unlikely to have a child hood onset.

Explanation

Since parents pass it on to their offspring, it is unlikely to have a child hood onset.

About This Quiz

Genetics Homozygous Quiz Questions - Quiz

There are two types of Allele that a person can have and they are either dominant or recessive. Over the past week in genetics class. The quiz below... see moreis made up on a series of questions that are designed to test your understanding when it comes to genetics homozygous. Do you feel like you can tackle it with ease? Give it a shot and see how much you understood.
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2. Billy has the following genotype I^A I^B; +/- Penny has the following genotype I^A I^A; +/- Which one of the following blood types could be found among the offspring

Type O positive

Type AB negative

Type B positive

All of the above could be found

Neither parent has an i allele, so the offspring can not be type 0. All offspring get at least one A allele, so the offspring can not be type B.

Explanation

Neither parent has an i allele, so the offspring can not be type 0. All offspring get at least one A allele, so the offspring can not be type B.

3. Red hair is recessive to dark hair. Jenny has red hair and has 2 children with Tony who does not have red hair, but his mother does. What is the chance that both of their kids have red hair?

1/4

1/2

1/8

3/4

R= Dark hair r=red hair. Jenny is r/r Tony must be R/r since his mother has red hair but he does not. If they have 2 kids, the chance they both have red hair is 1/2 X 1/2 =1/4

Explanation

R= Dark hair r=red hair. Jenny is r/r Tony must be R/r since his mother has red hair but he does not. If they have 2 kids, the chance they both have red hair is 1/2 X 1/2 =1/4

4. The A and B blood types differ by a carbohydrate at the end of a chain of carbohydrates. In type O blood neither type of carbohydrate is added to the chain. There is a condition called The Bombay phenotype in which the carbohydrate which normally has the A or B carbohydrates attached is missing. This is a recessive condition on another chromosome. Individuals who have this condition cannot have blood type A, B or AB even if their ABO alleles give that blood type. We will use M to indicate the dominant allele and m to indicate the recessive allele. Someone who is type O; +/- ; M/m has children with someone who is type AB; +/-; M/m. What is the chance that they have a type B positive child? Note that the M gene has no effect on the +/- gene.

3/4

9/32

9/64

1/32

There is a 3/4 chance of not having the Bombay phenotype. There is a 1/2 chance of being B and there is a 3/4 chance of being positive. 3/ X 1/2 X 3?4 =9/32

Explanation

There is a 3/4 chance of not having the Bombay phenotype. There is a 1/2 chance of being B and there is a 3/4 chance of being positive. 3/ X 1/2 X 3?4 =9/32

5. The pedigree below is

Autosomal Recessive

Autosomal Dominant

Sex linked recessive

Sex linked dominant

It skips generations so it can not be dominant. It only affects males, making it likely to be sex linked.

Explanation

It skips generations so it can not be dominant. It only affects males, making it likely to be sex linked.

6. The genotype off the individual indicated by the arrow is

XA/Y (A should be superscript)

X/A/Xa (A and a should be superscript)

XA/XA (A should be superscript)

A/a

Since it is sex linked, the X designation is used. Since the indicated female gives rise to both affected and unaffected males, she must be heterozygous. (Also see that her father has it and she does not. This also means she must be heterozygous

Explanation

7. In cats, the Manx (M) allele results in cats without tails, while the recessive allele (m) allows for tail growth. Homozygous M/M cats dies before birth. If 2 Manx cats mate, and they have 3 offspring, what is the chance that at least one has a tail?

2/3

1/3

8/27

19/27

The chance that none of the Manx cats has a tail is 2/3 X 2/3 X 2/3 =8/27
The chance that at least one has a tail is 27/27-8/27=19/27

Explanation

The chance that none of the Manx cats has a tail is 2/3 X 2/3 X 2/3 =8/27
The chance that at least one has a tail is 27/27-8/27=19/27

8. Billy has the following genotype I^A I^B; +/- Penny has the following genotype I^A I^A; +/-What is the chance that they have a child who is type A negative?

None

1/4

1/8

1/16

There is a 1/2 chance that the child is type A and a 1/4 chance that the child is -. 1/2 X 1/2 =1/4

Explanation

There is a 1/2 chance that the child is type A and a 1/4 chance that the child is -. 1/2 X 1/2 =1/4

9. The pedigree below is

Autosomal Recessive

Autosomal Dominant

Sex linked Recessive

Sex linked Dominant

Every individual who has it has at least one parent who has it. Males pass it to both sons and daughters so it can not be sex linked dominant.

Explanation

Every individual who has it has at least one parent who has it. Males pass it to both sons and daughters so it can not be sex linked dominant.

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Oct 08, 2024

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Feb 04, 2014

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Genetics Homozygous Quiz Questions