- Each parent carries one sickle cell allele
- Sickle cell anemia is a recessive trait in human
- Hence, each parent has one dominant gene and a recessive gene for sickle cell anemia

- Each parent has one dominant gene and a recessive gene for sickle cell anemia
- Heterozygous dominant organisms have one dominant gene and one recessive gene
- Therefore, both parents are heterozygous dominant for sickle cell anemia

- Both parents are heterozygous dominant for sickle cell anemia
- If a heterozygous dominant organism is crossed with a heterozygous dominant organism , then the offspring will have a 25% probability of being homozygous recessive
- So, the offspring of heterozygous dominant parents will have 25% probability of being homozygous recessive for sickle cell anemia

- The offspring of heterozygous dominant parents will have 25% probability of being homozygous recessive for sickle cell anemia
- Homozygous recessive organisms will show the recessive trait
- So, the offspring of heterozygous dominant parents will have 25% probability of having sickle cell anemia

- The offspring of heterozygous dominant parents will have 25% probability of having sickle cell anemia
- One in four is the same as 25%
- Hence, one in four of the offspring of heterozygous dominant parents will have sickle cell anemia

Hence, one in four of the offspring of heterozygous dominant parents will have sickle cell anemia
Question: Sickle cell anemia is a genetic disease caused by an autosomal recessive gene. If each parent carries one sickle cell allele, what are the chances that their child will have sickle cell anemia?
Context: - One in four is the same as 25% 
- Each parent carries one sickle cell allele 
- Sickle cell anemia is a recessive trait in human 
- If a heterozygous dominant organism is crossed with a heterozygous dominant organism , then the offspring will have a 25% probability of being homozygous recessive 
- Homozygous recessive organisms will show the recessive trait 
- Heterozygous dominant organisms have one dominant gene and one recessive gene