Answer:
The introns of protein-encoding nuclear genes of higher eukaryotes almost invariably begin (5') with GT and end (3') with AG. In addition, the 3'subterminal A in the “TACTAAC box” is completely conserved; this A is involved in bond formation during intron excision.
Sunlight is the main energy source
I'm not sure how exactly you wanted this question to be answered. You're either talking about the symmetry where animals would have two legs or two arms for example and thus producing a pair of each muscle on both sides of the body, or you're refering to the development of agonistic and antaonistic muscles where each of them served a different purpose; either extending or contracting.
A mutation can allow a organism to adapt to the environment and example can be the case of the peppered moth which has two variations a white colored one and a black colored one. The white colored ones were able to survive better that the darker ones because of how they were able to camouflage with the lichen located in the trees. However, after a while smoke particles that were released by industries darkened the trunk of the trees making the white moths visible and allowing the darker colored ones to survive. Another example can be on how organism can be resistant to bacteria this allows the animal to survive and reproduce offspring with the same mutation. I hope this helps...
Answer:
Chloroplast
Explanation:
Both plant and animal cells have mitochondria, nuclei, and cell membranes. However, only plants have chloroplasts, as they need them to photosynthesize. Animals don't photosynthesize, so their cells don't contain chloroplasts. Hope this helps!