Answer:
option 1
Explanation:
In assemblying the nucleosome, this reaction occurs in two main steps. the H3 and H4 are recruited first to the DNA in pairs forming the H3/H4 tetramer; meaning two of H3 and two of H4. This gives rise to the nucleosome precursor. Then after this, the dimers of both H2A/H2B are recruited to this precursor, to give rise to the octamer structure around which the DNA is wrapped.
Answer:
Your respiratory system is the network of organs and tissues that help you breathe. This system helps your body absorb oxygen from the air so your organs can work. It also cleans waste gases, such as carbon dioxide, from your blood. Common problems include allergies, diseases or infections.
Answer:
a. When a fetus is 13-15 weeks old
Explanation: is correct
The statement that is true is active transport moves against the concentration gradient.
<h3>WHAT IS ACTIVE TRANSPORT</h3>
Active transport is one of the two types of cellular transport that involves the movement of molecules against a concentration gradient.
This moves that movement occurs from a region of lower concentration to a region of higher concentration. Since movement is against a concentration gradient, it involves input of energy (ATP).
Therefore, the statement that is true is active transport moves against the concentration gradient.
Learn more about active transport at: brainly.com/question/2503897
The least dense layer of the atmosphere is the exosphere as it is the outer most layer of the atmosphere. Hope it helps!