Explanation:
it is the diagram of an ovum or a human egg
A- follicle cells
B- zona pellucida
C- chromosomes
D- vitelline membrane
It is an organic catalyst. It speeds up certain chemical reactions in the body.
<span>How many openings are in the digestive system of flatworms? Answer: 1
Flatworms digestive system is called 2-way which mean the same opening is used for eat and removing waste. That's why it only has one opening. Human system is one way since we eat from the mouth and remove waste from the anus.</span>
