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....
Answer:
Through the study of meteorites, their chemical composition of silicates—material made of silicon and oxygen. Others contain metal—nickel and iron. Knowing what the meteorite was composed of lets you know where it came from. Chondrites are composed of hardened lava - this is occurred at the beginning of the solar system (4.5 mya). Carbonaceous chondrites contain carbon and water which formed away from the sun.
Explanation:
How did the sunflowers depict their rivalry in the image? Why should they fight it out?
The reason I've chosen this as a scientific topic is because the area is covered in sunflowers. With the conditions of their surroundings, living organisms attempt to live. As a result, there is rivalry among the organisms.
The definition of cell theory is as follows: <span>a </span>theory<span> in biology that includes one or both of the statements that the </span>cell<span> is the fundamental structural and functional unit of living matter and that the organism is composed of autonomous </span>cells<span> with its properties being the sum of those of its </span>cells<span>.</span>