Light energy is initially converted into chemical energy in he form of two compounds: NADPH, a source of energized electrons and ATP, the versatile energy currency that the light reactions produce no sugar, that happens in the second stage of photosynthesis, the Calvin cycle.
The answer is all of these occur. The tetrads need to be made before crossing over occurs, which only occurs in prophase 1. That automatically means it has to be all of the above.
The circulatory system is mainly made up of the heart and the blood vessels. It is closely related to the respiratory system which is primarily made up of the lungs. The digestive system is primarily made up of the gastrointestinal tract. This simply means your mouth, esophagus, stomach, small and large intestines, and rectum up until your anus. All the cells in the human body are kept alive by these systems working together in harmony.
The heart pumps blood throughout the whole body via the blood vessels. Blood, particularly red blood cells (RBC), carry oxygen and nutrients inside of them and release them to the other cells in the body. Oxygen comes from the lungs in the respiratory system every time we breathe in air. Nutrients come from the digestive system after food has been broken down to small components that can be utilized by the cells in the body.
