To function properly, heart muscle cells require a steady supply of oxygen. After a heart attack, small amounts of lactic acid are present. What does this evidence suggest about the nature of a heart attack?

Mario performed an experiment to determine if photosynthesis was affected by the amount of light that a plant received. what could he have done to increase the validity of his data? reduce the number of plants. remove the 1 hour group. add a 0 hours control. measure the oxygen in liters

Explain what a zygote is. use the terms egg cell, sperm cell, and fertilization in your explanation.

This is a biological reaction due to a stimulus. i need this quickly !