Which of the following explains why the allele for sickle-cell disease remains at a relatively high level in the population?
a) it is the dominant allele.
b) it confers protection from malaria to carriers.
c) it is not harmful enough to be selected against.
d) it keeps returning to the population through mutation.

In terms of alternation of generations, the internal parts of the pollen grains of seed-producing plants are most similar to a ) moss sporophyteb) moss gametophyte bearing both male and female gametangiac) fern sporophyted) fern gametophyte bearing only antheridia

9. the history of life on earth is recorded in

Use the above pedigree for questions 1,2, and 3 1. what kind of genetic disorder is represented in the pedigree? a. recessive b. dominate refer to the pedigree in question 1. 2. is the mutated gene in this disorder located on a sex chromosome (x or y) or an autosome? a. sex chromosome b. autosome refer to the pedigree in question 1. 3. which generation has individuals that you are certain are heterozygous for the mutated gene? a. generation 1 b. generation 2 c. generation 3