Explain briefly HOW we have different cell types (blood, skin, muscles, nerves, etc.) *

Everybody is born with different blood cells, skin tone etc . That depends on your parents and the actual spermatozoon that got to the egg and eventually turned out to be you . That means that is up to the genes and races that you’ve been mixed with and created of . Sometimes even siblings have slight differences in their skin tone ,eye color etc . The genes and races or stuff like that, that you’re mixed with may pop up in different ways for you and your siblings i don’t know if that makes sense

blood enters the heart through two large veins, the inferior and superior vena cava, emptying oxygen-poor blood from the body into the right atrium of the heart. as the ventricle contracts, blood leaves the heart through the pulmonic valve, into the pulmonary artery and to the lungs where it is oxygenated.

your answer would be a, maximum exploitation of resources.