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....
"Gravitational attraction" is initially responsible for the formation of the clumps of matter within this interstellar cloud.
<u>Answer:</u> Option C
<u>Explanation:</u>
About 4.6 billion years ago, the solar systems were a bunch of gases and dusts, referred to solar nebula. Gravity squeezed the material as it started to rotate, creating the sun at the middle of the fog.
The rest of the material began to accumulate with the sunrise. The smaller particles moved together to form larger particles that were connected by gravity. As lumps develop, gravity increases and turns into kinetic energy of moving particles that collide and produce heat.
The disorder where the grandfather and the grandchild are affected is related with the X chromosome and is called Sex linked or X linked disorder.
<h3><u>Explanation:</u></h3>
All the sex linked disorders are recessive in character i.e the normal allele is dominant over the mutated allele. In females, there are 2 X chromosomes, so the mutated allele is only expressed when there are both the mutated alleles, else its masked by the dominant normal allele. But in males, there's only one X chromosome, so if a mutated allele is present, it's readily expressed.
If the Grandfather is diseased, then he must have that mutated allele in X chromosome. Through reproduction, its received by the mother, but she is normal because the other allele received from grandmother was normal. But mother has one of the X chromosomes with mutated allele, which is received by the grandson who again becomes diseased.
So the disorder must be X linked disorder
<span>ne day, while walking through a crowded zoo, I noticed that suddenly there were no people walking on the path anymore. I happened to be next to the gorilla den, which was just a cul-de-sac at the end of a long, curved trail. I thought I'd go in since I was there. </span>
