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

humans are now responsible for causing changes in the environment that hurt animals and plant species. we take up more space on earth for our homes and cities. we pollute habitats. human activity often changes or destroys the habitats that plants and animals need to survive.

what's the question?

above statement is not a true statement about the open ocean because the open ocean has low levels of nutrients. most of the photosynthetic activity on earth occurs in the open ocean within the photic zone. organisms in the deep ocean are exposed to frigid temperatures and total darkness but it does not begin at the low-tide mark.