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Anonymous sara5656
wrote...
A year ago
1) SEE FIRST PHOTO ATTACHED PLEASE AND ANSWER PLEASE



2) Polydactyly is a rare human trait that causes an individual to have six digits (fingers or toes). An autosomal dominant gene causes the extra digit to develop.

SEE SECOND IMAGE TO ANSWER PLEASE
 

Choose the correct genotypes of all individuals in this pedigree chart.


I-1 is Answer
 

I-2 is Answer
 

II-1 is Answer
 
II-2 is Answer
 
II-3 is Answer
 
II-4 is Answer
 
II-5 is Answer
 
III-1 is Answer
 
III-2 is Answer
 
III-3 is Answer
 
III-4 is Answer
 

III-5 is Answer
 
III-6 is Answer
 

Individuals III-1 and III-2 are Answer  twins.










3)    SEE THIRD IMAGE ATTACHED TO ANSWER PLEASE

Which of the following states a valid conclusion based on the pedigree above?

a. All children of individuals I-1 and I-2 could be carriers of the red-green colour blindness allele.

b. Individual II-2 passed on the red-green colour blindness allele to individual II-1.

c. Individuals II-5 and II-6 are carriers of the red-green colour blindness allele.

d. Individual I-2 does not carry the red-green colour blindness allele.

e. It is not possible to determine whether individuals III-2 and III-3 are carriers of the colour blindness allele.
 







4) Sickle cell anemia is an inheritable red blood cell disorder that results in sickle-shaped red blood cells. The sickle-shaped red blood cells can stick to blood vessel walls and cause a blockage or slow the movement of blood throughout the body.

Let HbS be the allele for sickle cell anemia and let HbA be the allele for normal red blood cells.

SEE 4 IMAGE TO SEE THE QUESTION






5) SEE  IMAGE  5 ATTACHED






6)  SEE IMAGE 6 ATTACHED





7) SEE IMAGE 7 ATTACHED





8) Use the following information to answer the next four questions.

A defective gene on chromosome 15 causes Tay-Sachs disease. It is a central nervous system neurodegenerative disease that most often affects infants, though older children and adults can have late-onset forms of the disease. The defective gene prevents the body from making a protein called hexosaminidase A. Without, hexosaminidase A, chemicals called gangliosides build up in the nerve cells of the brain, destroying brain cells.

A couple has one genetic daughter with Tay-Sachs disease and three other unaffected genetic children. Neither the mother, nor father, nor any of the biological grandparents of the affected daughter have had the disease. Tay-Sachs disease most likely demonstrates what type of inheritance?


a. autosomal dominant

b. X-linked dominant

c. autosomal recessive

d. X-linked recessive




9) SEE IMAGE ATTACHED (8)



10) If individuals II-1 and II-2 have another child, what is the probability they will have a child affected by Tay-Sachs?

a. 1.00



b. 0.50

c. 0.00

d. 0.25








11) Achondroplasia is a form of dwarfism caused by a mutation in a single gene. Two individuals with achondroplasia marry and have an affected child and later have a second child that is average in height.

From this you can conclude

a. achondroplasia is produced by a dominant allele

b. achondroplasia is a result of codominance

c. achondroplasia is produced by a recessive allele

d. achondroplasia is a result of incomplete dominance






12) Trait W is found in the individuals represented by the shaded symbols in the following pedigree. Trait W is rare in the general population.

Which of the following patterns of transmission is consistent with this pedigree?

a. X-linked recessive

b. Autosomal dominant

c. Autosomal recessive

d. X-linked dominant


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wrote...
Valued Member
A year ago
Please post one question per topic. Many of these take over 20 minutes to answer.
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wrote...
Valued Member
Educator
A year ago Edited: A year ago, bio_man
#3 --  It is not possible to determine whether individuals III-2 and III-3 are carriers of the colour blindness allele.

Explanation:

Red-Green colour blindness is a X-linked recessive trait. All male progeny will get X-chromosome from mothers only. All female progeny will get one X-chromosome from mother and the second X-chromosome from the father.

#8 -- When answering inheritance questions it's important to remember a few key things. When it comes to X linked it's very rare to affect women because they get two copies and if one is broken or damaged they will just use the other. (women are XX men are XY so x linked will affect men more often) with dominant traits they just need one copy to show the trait, such as brown eyes. So, since it's a female affected it's pretty safe to rule out X-Linked. And only one child of 4 we can rule out mitochondrial and since neither parent or grandparents are affected we can rule out dominance inheritance leaving us only autosomal recessive as the answer.

#10 -- Normal = ¾ = 0.75

Tay-sachs = ¼ = 0.25

#11 -- Achondroplasia is produced by a dominant allele.

Dominant allele cen express itself in both homozygous and heterozygous condition, but recessive allele can express only in homozygous condition.

If both the parents are affected, but they give rise to normal child (second child), then the mode of inheritance is said to be dominant one.

Both the parents are heterozygous (Aa). In Aa × Aa cross, expected ratio of affected (AA/Aa) to normal (aa) child = 3 : 1

The first child is affected, carrying at least one dominant allele in his/her genotype; the second child is normal/average, carrying two recessive alleles in his/her genotype.

Does that help?
Anonymous Author
wrote...
A year ago
thanks
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