Answer:
protein-coupled receptors.
D oxygen there was no free oxygen on the earth
Answer:
Fraternal twins can be different genders because they are two completely different eggs getting fertilized; but even two same gender fraternal twins do not look completely alike. Whereas for identical twins since one egg is splitting into two, the two cells have the same exact DNA make up and chromosomes.
I also believe the technical part of it is to do with genetics, like ressesive and dominant genes, because they can be the same gender, ex. both girls and one has blue eyes, fair skin, and blonde hair, the other twin has brown eyes, black hair and tan skin. The parents could be part of the genes but there is also grandparents maybe the mom's mom has blonde hair and blue eyes, with fair skin. But the dad he has brown eyes, black hair and tan skin. The moms genes were recessive, but the grandma's genes were dominant.
I tried to explain it as best as I could I hope it helps!
Blood and lymph are the two circulating fluids in the animal body. Blood belongs to the circulation system whereas lymph belongs to the lymphatic system. Blood contains pigments which carry oxygen. Therefore, blood can be found in different colors in different types of organisms. But, lymph is a colorless fluid. Blood is composed of red blood cells, white blood cells, platelets and a fluid called plasma. Lymph is composed of white blood cells and a watery fluid. Both blood and lymph possess a circulatory function as well as an immune function. The main difference between blood and plasma is that blood circulates inside blood vessels whereas lymph circulates inside lymphatic vessels.
I'm not sure if you needed a translation or an answer but i'll give both:)
"Why is it that in some countries it is day while in others it is night"
because at different times of the day the sun hits different areas of the earth. I hope this helps!
porque en diferentes momentos del día el sol golpea diferentes áreas de la tierra. ¡Espero que esto ayude
