Which of the following occurs in all species of living organisms and may lead to an increase in genetic variation? a. mutations in the genomeb. crossing-over in meiosisc. random assortment of chromosomesd. alternative splicing of mrna

a. the production of carbon dioxide through the process of photosynthesis

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.

there is not 1 highest source of protein, but there are many; meats, fish, poultry, seafood, cheese, eggs, yogurt and milk. the only non complete animal food that is beneficial is gelatin.

sorry if this did not , have a great day!

the correct answer is d