What is photo synthesis? imm need friend anyone like to be my friend !

What would be the result if crossing over did not happen during meiosis in humans? a. there would be less genetic variation in humans. b. parents would be more likely to look like their children. c. the human population could not reproduce. d. children would have more chromosomes.

Where do the respiratory and circulatory systems meet? a. in the heart b. in the muscles c. in the lungs d. in the brain

Hemoglobin is a proton that carries oxygen around your body what is hemoglobin made from