Which of the genotypes are heterozygous?
AA
Аа
aa

Which is a function performed by stem cells in the skin a. replacing lost skin cells b. making cells for the intestines c. growing new organs d. differentiating into brain cells plz apex

The double bond between a carbon atom and two oxygen atoms (a molecule of carbon dioxide) has two characteristics. what are they? a.an ionic bond is formed between the oxygen and carbon atoms. b.four valence electrons are shared. c.two valence electrons are shared. d.valence electrons are shared between oxygen atoms.

In a cladogram, what occurs at a node? a derived trait appears. evolution is stopped. an ancestor dies. the cladogram ends. aa as s as ss what are the chances that their offspring will have sickle cell anemia? 0% 25% 50% 100%