Hydroxyapatite is the major component of bone that contributes to its hardness.
D replace large, martyrs tresss will amalle
Answer:
I think you're referring to the Metaphase...
Explanation:
During Cell Division (or, rather before!) the DNA needs to be replicated. This normally is done by DNA Polymerase, and results in two identical double strands (the "Sister Chromatids".
These chromatids are held together at the Centromere, which will be the heart of the "X"-shape. After that the DNA is packed into Chromosomes by winding it around proteins called Histones. If I remember correctly there are 5 different Histones.
This "Zipping Up" makes the chromosomes more visible.
As the two sister chromatids are still connected, the result is the X-shaped Metaphase Chromosome....
C.Glucose
The stomata of plants will close during hot and dry day. This cause a decrease in concentration of carbon dioxide and increase in oxygen concentration in the plant. Photorespiration occur.
As carbon dioxide in photosynthesis is used to produce glucose molecules, the production of glucose molecule will decrease.