a: animals evolved from simpler forms
Answer:
(a) Muscle B contracts and muscle A relaxes
(b) The Heart
Answer:
While in mitosis, genes are generally transferred faithfully from one cellular generation to the next; in meiosis and subsequent sexual reproduction, genes get mixed up. Sexual reproduction actually expands the variety created by meiosis, because it combines the different varieties of parental genotypes.
Explanation:
I did research
the respiration in human start from breathing.the oxygen is inhale and passes through larynx and reaches upto trachea and it goes in the bronchus.it is also divided into bronchoioles. it leads into lung
the bronchoioles that enter in the lung lead to small air sac called alveoli and it exchange gases and here exchange of gas occur and carbon dioxide is transported back to nostril through same passage and the canbondioxie is exhaled.in this way the process of respiration is completed
hope this helped..