The heart is a muscular organ that pumps blood. blood that contains waste materials is brought to the heart by blood vessels. this blood enters the and then moves down. the presence of prevents the backflow of blood inside the heart

Witch type of microscope is used to view very small cell components like proteins and dna?

An organ system consists of a group of organs that performs specific functions necessary for the survival of an organism. humans have eleven different organ systems: integumentary, skeletal, muscular, nervous, endocrine, circulatory, lymphatic, respiratory, digestive, urinary, and reproductive. discuss the function of neurons, the brain and the spinal cord within the human nervous system while explaining the interrelationship of each organ.

Using meiosis, the sporophyte produces spores that are .