Hey. The first sound is the "lub." This is what you hear once the mitral and tricuspid valves of the heart close, which are the valves between the atria and the ventricles! Super cool. It is your third answer choice.
A copy of the DNA is made and then the cell divided
Answer:
ai) P= Red blood cell Q= Alveoli
ii)1. It gives the lungs a large surface area to volume ratio.
2. It is moist and thin.
b) P has a disc or biconcave shape which allows the O2 to bind to it with the help of a protein called haemoglobin for it to be transferred to various parts of the body.
c) Carbon monoxide will bind to the haemoglobin to form carboxyhaemoglobin causing oxygen disruption
During mitosis, chromosomes are moved and separated through the use of spindles composed of microtubule structures.
Explanation:
Throughout mitosis, the chromosomes are initial replicated (copied) and so distributed into a pair of new "daughter" cells. They're replicated throughout the S section of interphase, and within the following phases (prophase, metaphase, anaphase, telophase) are organized, separated, and repackaged at opposite ends of the cell, at that purpose the cell divides. The strand of chromosomes split just like the cell throughout the cellular division. They split in half.
