Answer:
Muscle contraction is defined at the molecular level by myosin molecules bringing actin filaments together.
Explanation:
Researchers at Osaka University have created new electron cryomicroscopy images with remarkable resolution that reveal unusually substantial conformational changes in the myosin molecule during the pull.
Hello!
Clubbed finger tips usually means the person has lung or heart disease. It only makes sense if he smokes a lot of cigarettes (2 packs is a lot). The more he smokes everyday, the higher chance he could get the disease. Just to be sure, you might want to do tests for lung and heart disease. The coughing up blood might be a the result of smoking. It really depends on his state of shape and all of that stuff.
Have a lovely day! ~Pooch ♥
Answer: The nervous system
Explanation:
The first part of the embryo to develop is the neural tube, which will become the spinal cord and brain. As the nervous system starts to develop, the tiny heart starts to pump blood, and other parts of the body—such as the digestive tract and backbone—begin to emerge.
I believe it is D! I hope this helps : )