1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
yaroslaw [1]
3 years ago
15

An individual with Huntington disease has two normal parents. What are plausible explanations for this pattern of inheritance? C

heck all that apply. Check All That Apply A spontaneous mutation occurred in the mother's germline to produce a mutant HD allele. A spontaneous mutation occurred in the mother's germline to produce a mutant HD allele. A spontaneous mutation occurred in the father's germline to produce a mutant HD allele. A spontaneous mutation occurred in the father's germline to produce a mutant HD allele. A spontaneous mutation occurred in the individual's germline to produce a mutant HD allele. A spontaneous mutation occurred in the individual's germline to produce a mutant HD allele. Huntington disease shows incomplete penetrance.
Biology
1 answer:
Vitek1552 [10]3 years ago
6 0

Answer and Explanation:

The Huntington disease is caused by a mutation in the gene that codifies for the Huntingtin protein (Htt). The mutation produces an altered form of the protein leading to the neuron´s death in certain areas of the brain.

The Huntington disease characterizes for being,

  • Hereditary, passing from generation to generation. To express the disease, a person must have been born with an altered gene.
  • Autosomal, affecting men and women equally, because the mutated gene is located on an autosomal chromosome.
  • Dominant, which means that by getting only one copy of the altered gene coming from any of the parents, the receiving person will express the disease. The mutation in the gene dominates over the normal gene copy.
  • Expressed by heterozygosis. Most people affected by the disease are heterozygous, with a normal copy and a mutated copy.

There are just a few cases all around the world (3% approximately) in which the disease is expressed with no family history. The progenitors are not affected by the mutation. These cases are very rare and are called <u>"de-novo" mutations.</u> A new mutation is spontaneously produced and it is not inherited from any of the parentals. It consists of an increase in the number of CAG repetitions. In a normal person, the number of CAG repetitions is less than 35. When there are 40 or more repetitions it occurs the disease. But when there are between 35 and 39 repetitions, the penetrance of the disease is incomplete. This is a "gray zone". Those alleles that fall in the gray zone are unstable and might produce the HD. Individuals with these unstable alleles have a tendency to increase the number of repetitions from generation to generation until the number reaches 40 repetitions and the person expresses the disease. This <u>usually occurs in the paternal germinal line</u>, as it is particularly unstable in sperm and probably meiosis greatly affects their instability, causing an increase in the number of CAG repeats.

You might be interested in
the DNA sequence reads ACGTTCATT before a mutation occurs. after the mutation, the DNA sequence reads ATCGTTCATT. which type of
11Alexandr11 [23.1K]
Addition, you added an extra T between the first A and C
5 0
3 years ago
Read 2 more answers
) Consider a pea plant- it has a gene controlling seed color- yellow Vs green; another gene controlling seed texture-smooth Vs w
lana [24]

Answer:

Yellow smooth  - 9

Yellow wrinkle - 3

Green smooth- 3

Green Wrinkle - 1

Explanation:

Let the green color of the seed be depicted by "G" and the yellow color of the seed be depicted by "g"

Let the smooth the seed be depicted by "R" and wrinkled seed be depicted by "r"

F1 cross -  

true breeding smooth green plant ( RRGG) and true breeding wrinkled yellow (rrgg)

F1 gamete will be RG, RG, rg, rg

F1 offspring will be RrGg , Thus all F1 offspring will be heterozygous smooth and yellow.  

Thus,  R is dominant over r and g is dominant over G

F2 Generation –  

RrGg x RrGg

Gametes will be RG, Rg, rG, rg

RG         Rg          rG           rg

RG RRGG RRGg RrGG RrGg

Rg RRGg RRgg RrGg Rrgg

rG RrGG RrGg rrGG rrGg

rg RrGg Rrgg rrGg rrgg

R is dominant over r and g is dominant over G

Genotypes are –  

RRGG - 1  (Smooth Green)

RRGg-2  (Smooth yellow)

RrGG-2  (Smooth Green)

RrGg-4  (Smooth yellow)

RRgg- 1  (smooth yellow)

Rrgg – 2  (Smooth yellow)

rrGG – 1  (wrinkled Green)

rrGg – 2  (Wrinkled yellow)

rrgg – 1  (wrinkled yellow)

Yellow smooth  - 9

Yellow wrinkle - 3

Green smooth- 3

Green Wrinkle - 1

4 0
2 years ago
Polygenic characteristics are disproportionately affected by natural selection.
rodikova [14]

Answer:

The natural selection on polygenic traits affects selection.

Explanation:

The natural selection process allows changes in frequencies of alleles in a character that is determined by single gene. The polygenic characteristics are disproportionately affected by natural selection as natural selection affect the phenotype distribution.

This occurs in three ways that are disruptive selection, stabilizing and directional selection.

6 0
3 years ago
I am a semi-permeable layer around the cell that encloses the contents of the cell. What am I? *
astraxan [27]
It is the cell membrane
4 0
3 years ago
Which property of water causes water drops to bead on a freshly waxed car
cricket20 [7]
What it actually is, is that wax is hypotonic and moves away from the water so the water can’t spread out
6 0
3 years ago
Other questions:
  • What is the shortest phase of the cell cycle
    9·2 answers
  • The rise in blood glucose levels after eating stimulates the pancreas to secrete the hormone ___, causing blood glucose levels t
    5·1 answer
  • An infection acquired by a patient in a healthcare facility is known as a(n) ________ infection.
    11·1 answer
  • What event occurs in photosystem 1?
    14·1 answer
  • Which plant is often used as a soil conditioner
    5·2 answers
  • HELP PLEASE!! I wanted to know, well this form usatestprep.com IT IS ALSO 12 POINTS IF U ANSWER!!!
    14·1 answer
  • The first step in treating drinking water, called ____________________, involves passing water through a series of screens.
    13·1 answer
  • Type the correct answer in the box.
    10·1 answer
  • What is meaning of photosynthesis ​
    10·1 answer
  • The use of vaginal inserts of Lactobacillus cells to restore healthy vaginal biota is an example of ________.
    13·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!