I think the correct answer would be A. The yolk sac becomes the placenta. It is membranous sac that is attached to the embryo. It provides all the nutrition and the blood cells needed by the embryo. It is also called the umbilical vesicle.
The ecological relationship between termites and the wood-digesting protozoans that live in their gut is an example of mutualism. Thank you for posting your question here at brainly. I hope the answer will help you. Feel free to ask more questions here.
Answer:
option A is correct
Explanation:
condensation is the process by which water vapors in the air are converted to liquid water
Answer:
evolution of bidepadlism,
increase in enamel thickness,
regular use of stone tools, enlargement of brain to around 1,450 cc
Explanation:
Answer:
petals are colorful because the color attracts birds, bees and other insects. The insects land in the flower and spread pollen, which helps fertilize the flowers and create seeds. Some flowers change color as they grow older.
