Answer:
approximately 4.5 billion years ago
Explanation:
1.) A persons genes are found in their chromosomes. The correct answer is D, your chromosomes. The correct answer is D.
2.) The shape of DNA is called a double helix. The strands run opposite each other and twist together. The correct answer is B.
3.) The relationship between a chromosome and DNA is that chromosomes are made of DNA. The correct answer is A.
4.) One thing that parents pass on to their offspring is genes. For example, hair color, eye color, skin color. The correct answer is A.
Answer:
Your circulatory system delivers oxygen-rich blood to your bones. Meanwhile, your bones are busy making new blood cells. Working together, these systems maintain internal stability and balance, otherwise known as homeostasis. Disease in one body system can disrupt homeostasis and cause trouble in other body systems
The only independent variable in this experiment is the amount of nitrogen Sarah uses. All of the other variables are dependent on other factor and processes, but Sarah controls the amount of nitrogen that she uses for each plant.
