Question

Despite the devastating effects of sickle-cell anaemia, why does the mutated allele responsible for this disease...

Despite the devastating effects of sickle-cell anaemia, why does the mutated allele responsible for this disease remain prevalent in some regions of the world? In your answer, explain the roles of relative fitness and natural selection.

0 0
Add a comment Improve this question Transcribed image text
Answer #1

Sickle Cell anemia is a disease inherited from parents through autosomal recessive pattern.

So to actually have the condition the offspring gets a recessive allele copy from both parents.

The mutation for this disease occurs in chromosome 11 so it is not sex linked disease.

This is the chromosome responsible for Haemoglobin production, which is responsible for binding with Oxygen.

The gene responsible for this HBB. The alleles for this are HbA and HbS.

HbS is the recessive allele responsible for the sickle cell trait.

So if both the parent has HbS and it is passed on to the offspring then the condition occurs, SCD (Sickle cell disease).

We can see this through the following Punnet square where only one parent is the carrier for sickle cell trait.

Father - HbA HbA (Normal) Mother HbA HbS (carries sickle cell trait)

HbA HbA
HbA HbAA HbAA
HbS HbSA HbSA

Th colored box in the Punnett square shows that the next generation will have 50%chance of carrying the sickel cell trait and can passs on the disease if they marry a person who also carries the sickle cell trait.

Why does the mutated allele responsible for this disease remain prevalent in some regions of the world?

The reason for mutated allele remaining prevalent in certain regions of the world:

a. The person carrying the sickle cell trait marrying a person carrying the defect as they do not show the symptoms.

b. Since people carrying the SCT (sickle cell trait) do not show symptoms they are diagnosed as carriers of the disease.

c. Malaria being predominant in the African regions there was natural selection with people with SCD or SCT being immune to the disease.

d. The reason for immunity in SCT is that, when these carriers blood cells were infected with the malarial parasite their blood cells (collapses) forms a sickle shape which is then removed by the spleen along with the parasite. So people with SCT survived while those without the disease succumbed to malaria.

e. In sickle cell anemia the relative fitness also can be explained as people carrying the trait for sickle cell survive for a longer period into their reproductive age compared to their normal counterparts in the malaria prone environment.

Add a comment
Know the answer?
Add Answer to:
Despite the devastating effects of sickle-cell anaemia, why does the mutated allele responsible for this disease...
Your Answer:

Post as a guest

Your Name:

What's your source?

Earn Coins

Coins can be redeemed for fabulous gifts.

Not the answer you're looking for? Ask your own homework help question. Our experts will answer your question WITHIN MINUTES for Free.
Similar Homework Help Questions
  • Q5.1. Which of the following is FALSE? If a genetic disease reduces fertility and the allele...

    Q5.1. Which of the following is FALSE? If a genetic disease reduces fertility and the allele that causes the disease offers no other advantage, the allele will likely eventually disappear, due to natural selection. Natural selection does not favor individuals who are homozygous for the sickle- cell allele, because these individuals typically die before they are old enough to reproduce. Individuals who are heterozygous HbA/HbS are protected from malaria, and this is why sickle-cell disease persists in wetter, mosquito-prone regions...

  • explain, in detail, the relationship between malaria and sickle-cell anemia. Why is having one sickle-cell allele...

    explain, in detail, the relationship between malaria and sickle-cell anemia. Why is having one sickle-cell allele considered a selective advantage? Is this equally beneficial for someone who is homozygous recessive for sickle-cell? Why or why not? Note: use specific vocabulary to describe your answers (genotype, homozygous d, homozygous r, natural selection, heterozygous, etc)

  • 1. Which of the following is FALSE? A. If a genetic disease reduces fertility and the...

    1. Which of the following is FALSE? A. If a genetic disease reduces fertility and the allele that causes the disease offers no other advantage, the allele will likely eventually disappear, due to natural selection. B. Natural selection does not favor individuals who are homozygous for the sickle-cell allele, because these individuals typically die before they are old enough to reproduce. C. Individuals who are heterozygous HbA/HbS are protected from malaria, and this is why sickle-ce disease persists in wetter,...

  • I posted this question before but no answer I need to submit in 4 hours, please...

    I posted this question before but no answer I need to submit in 4 hours, please help. Although the following scenario is hypothetical, it is based on actual facts. Sickle cell anemia is an inherited form of anemia. Those with sickle cell anemia do not have enough healthy red blood cells to adequately carry oxygen to all the cells in their body. Normal red blood cells are flexible and round, and can easily move through the blood vessels. However, in...

  • A mutation in one of the hemoglobin genes causes sickle cell anemia. The sickle cell allele,...

    A mutation in one of the hemoglobin genes causes sickle cell anemia. The sickle cell allele, S, severely reduces fitness in people who are homozygotes, SS. In contrast, people with at least one normal hemoglobin allele, A, do not suffer the effects of sickle cell anemia, even if the individual is a heterozygote, AS. Interestingly, in areas with high rates of malaria, a single Sallele confers some resistance to malarial infection. Suppose there is a population with the observed and...

  • My Study on Sickle Cell Anemia Research In 500 words, answer the following questions 1.Select your...

    My Study on Sickle Cell Anemia Research In 500 words, answer the following questions 1.Select your study sample 2. How have you selected your sample? 3. How will you select your sample population and give the rationale behind your decision Please type the solution on the keyboard so that I can copy and paste Q. No 1. Answer : Sickle cell disease : It is defined as it is a chronic heriditory form of Anemia, in which the red blood...

  • Why Malaysians need a well-comprehensive social safety nets program? Achieving high growth while ignoring the welfare...

    Why Malaysians need a well-comprehensive social safety nets program? Achieving high growth while ignoring the welfare of the lower income group is an unwarranted act. Like the rest of the world, Malaysia suffers from the increasing gap between the rich and the poor despite the low incidence of absolute poverty today compared to in 1970s. Urban poverty is rising too together with the relative poverty due to income inequalities within and among the ethnic groups and the different social sectors....

  • frican Illness: A Case of tes! y Kevin M. Bonney Cohen School for Human Services and...

    REMOVED frican Illness: A Case of tes! y Kevin M. Bonney Cohen School for Human Services and Education Metropolitan College of New York, NY PartI-Sub-Saharan Safari A 51-year-old man named Robert Bragg reported to a hospital in the United Kingdom complaining of general malaise (discomfort), myalgia (muscle pain), fevers, headache, vomiting, and diarrhea. He complained that during the day he felt weak and tired; he was unsure if this was because his symptoms kept him awake ar'night, or if something...

  • 1. According to the paper, what does lactate dehydrogenase (LDH) do and what does it allow...

    1. According to the paper, what does lactate dehydrogenase (LDH) do and what does it allow to happen within the myofiber? (5 points) 2. According to the paper, what is the major disadvantage of relying on glycolysis during high-intensity exercise? (5 points) 3. Using Figure 1 in the paper, briefly describe the different sources of ATP production at 50% versus 90% AND explain whether you believe this depiction of ATP production applies to a Type IIX myofiber in a human....

  • Why are networks and industry relationships important to TWC? What other strategies could an eco-tourism business...

    Why are networks and industry relationships important to TWC? What other strategies could an eco-tourism business of this size use to source ideas and incorporate into its new product development strategy? Tasmanian Walking Company: Balancing luxury and adventure in a sustainable experience Gemma Lewis, PhD University of Tasmania, Australia the organic skincare range supplied by LITYA (Li'tya, 2016). Before introducing this new activity, TWC had to adapt certain treatments to ensure they maintained ocus on sustainable resaurce usage. Their outecor...

ADVERTISEMENT
Free Homework Help App
Download From Google Play
Scan Your Homework
to Get Instant Free Answers
Need Online Homework Help?
Ask a Question
Get Answers For Free
Most questions answered within 3 hours.
ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT