Answer: yolk sac
explanation:
the placenta does not develop for a long time so the alternate way of supplying the developing embryo is through the yolk sac which the embryo can receive nutrients and respiratory gas exchange through which the placenta will be formed later.
The serous fluid within the pericardial cavity works to lubricate the membranes of the serous pericardium. It is the space between the layers of the pericardium.
<h3>What is the pericardial cavity?</h3>
The pericardial cavity refers to the space between different layers of the pericardium in the heart.
The pericardium is one of the three tissues that form the heart (i.e., pericardium, myocardium, and endocardium).
The pericardial cavity is composed of a serous fluid capable of reducing surface tension and lubricating this layer.
Learn more about the pericardial cavity here:
brainly.com/question/2833911
It should be 4. As we can see the relative reactivity of enzymes increase in skins a which has a basic rnvironment. Correct me if I’m wrong please. Thanks
The closer a planet is to the Sun, the stronger the Sun's gravitational pull on it, and the faster the planet moves. The farther it is from the Sun, the weaker the Sun's gravitational pull, and the slower it moves in its orbit.
