Two Biology questions, please help Thank you very much :)

Aa x Aa will produce
[1/4 AA + 1/2 Aa] for 3/4 dominant phenotype
1/4 aa recessive phenotype


Sickle cell disease shows a heterozygous blend of parasite vulnerability with some normal red blood cells carrying hemoglobin Hb and some with hemoglobin that causes cells to sickle- Hbs.

There is a mixed expression to the malaria causing parasite; the overall impact is intermediate. The heterozygote overdominance in disease resistance is from the blended intermediate nature of the blood cells.
This in incomplete disease resistane with both genotype and phenotye having the same ratios
1/4 vulnerable to malaria
1/2 with reduced malaria and reduced sickle cell symptoms
1/4 expressing sickle cell anemia

I think probability of both parents giving recessive trait would be 1/4 since each one would be 1/2. For second one it could be skin color (black and white peopl have a kid lol)

You could also say hair color. Brown hair and blond hair parents and baby has light brown hair

1/4

And examples:
Wavy hair
Sickle cell disease (some people show mild symptoms)
Mordan (the eye color is blended here)