30 points , if you answer this question and right for sickle-cell disease, assume s is the dominant allele and s the recessive allele. which genotypes are possible for offspring of a carrier (ss) and a person who lacks the sickle-cell allele (ss)? a. ss, ss b. ss only c. ss, ss d. ss only

SS, Ss       is the answer

C. SS, Ss

Explanation:

Remember when doing the recessive alleles and dominant alleles you just need to do a punnet square, putting both alleles of the parents and set up the possibilities of the offspring.:

                            Mother

Father                S            s

   S                    SS         Ss

   S                    SS         Ss

So the four options are only SS and Ss, so the recessive gene will never actually be developed because the dominant is present in all of the combinations.

primary succession occurs in essentially lifeless areas regions in which the soil is incapable of sustaining life as a result of such factors as lava flows, newly formed sand dunes, or rocks left from a retreating glacier. secondary succession occurs