Ans.
Sickle-cell disorder is a genetic disorder, which shows defected red blood cells, due to mutation in the genes for hemoglobin protein.
Malaria is common in sub-Saharan Africa region and there, natural selection favored gene for sickle cells, because it might be beneficial to people having sickle cell disease that makes them able to survive in such condition and transmit their genes to offspring.
On the other hand, in those Africans, who moved to United States, where malaria is uncommon or absent, natural selection favored normal, wild type genes, resulting in fewer people with defected sickle cell.
Hence, sub-Saharan African population shows higher percentage of mutated gene for sickle cell as compared to population of United States.
Thus, the evolutionary process behind this difference is 'natural selection.'
Answer:
100%
Explanation:
No matter how many factors are in the cross, if an 2 purebred (homozygous individuals) are crossed, (one dominant, one recessive) the dominant phenotype will always be displayed.
Imagine a cross with between two individuals true breeding for 6 traits. One shows all dominant genotypes, one shows all recessive genotypes. The only gametes those individuals can pass on will always produce heterozygotes.
AABBCCDDEEFFGG x aabbccddeeffgg
The first individual can only give ABCDEFG alleles. The second individual can only give abcdefg alleles. Therefore, all offspring will be AaBbCcDdEeFfGg, and will therefore express the dominant trait.
Answer:ANSWER IS OPTION 'B'
Global climate is changing due to burning of fossil fuels and deforestation.
A group of cells that performs a similar function is known as tissue.
A physical change is basically a body change so like if a crayon is solid then sits in the sun for a long time it melts away that’s a physical change because it changes its physical appearance
