Approximately how many times does an average human heart beat in a lifetime?

What is the main function of the central vacuole in a plant cell? a. absorbs energy from the sun to produce food b. holds water and maintains turgor pressure c. breaks down molecules to release energy d. contains the cell's genetic material

Which of the following describes the difference in stimuli required to detect a difference between the stimuli? a. just noticeableb. signal detectionc. subliminald. top down

Stem cells found adult tissue such as in bone marrow brain muscle skin and liver are only capable of what