Sequences for the types of hemoglobin are shown. CCT GAG GAG
Sequence for wild-type hemoglobin
CCT GTG GAG
Sequence for sickle-cell hemoglobin
Sickle-cell anemia is caused by a mutation of one nucleotide in a gene. The type of mutation that causes sickle-cell anemia is known as
A) a frame-shift mutation
B) an insertion mutation
С) an inversion mutation.
D) a point mutation

stimulus is a change in the environment that causes an organism to react. the response is the reaction to the stimulus. some examples of stimuli for zebras are drought, to many predators, and bad feeding grounds such as dead grass or plants. zebras respond to stimuli just like all other living organisms

in a chemical reaction, the atoms and molecules produced by the reaction are called products. no new atoms are created, and no atoms are destroyed. in a chemical reaction, reactants contact each other, bonds between atoms in the reactants are broken, and atoms rearrange and form new bonds to make the products.