Chordates (phylum Chordata) are animals which are either vertebrates or one of several closely related invertebrates. They are united by having, for at least some period of their life cycle, a notochord, a HOLLOW DORSAL NERVE CORD
This illustrates <span>absolute threshold. The correct option among all the options that are given in the question is the second option or option "B".
</span><span>A spot in the middle of the retina that only contains cones is called the fovea. The correct option among all the options that are given in the question is the third option or option "C".</span>
Answer: 2 in 4
Explanation: if the parents are both RB, one would end up red, one would end up blue, and 2 would be heterozygous and end up presenting the incompletely dominant color of purple.
Because the three-horned alien is heterozygous, we know that three must be dominant to four, because the gene for the three horns is "hiding" the gene for four horns. Therefore, the three-horned alien has the genotype Tt (T for three horns, and t for four horns). The four horned alien must be tt, because that is the only way that a recessive trait may be seen. If you solve the punnet square on a cross between Tt and tt, you end up with half three (heterozygous) and half four (homozygous recessive) it is a bit easier to explain with something a little "closer to home" if you want me to explain it again, just say so, I don't mind!