Because there are too many sex chromosomes I think
Answer:
1. hydrogen; 2
2. it means two strands of DNA twisted around each other like a winding staircase
<h2>Answer </h2>
The components of the r group of amino acid structure varies among different amino acids
<u>Explanation </u>
As the functional group for amino acids is as:
R-CH-COOH
I
NH2
only R differs so amino acids also differs. If R is “H” then amino acid is glycine and if R is “CH3” then amino acid is alanine. Hence, R is different for different amino acids. Other components as alpha carbon ( C ), carboxyl group ( COOH ) and amino group ( NH2 ) is fixed for every amino acid.