Homologous chromosomes pair up and exchange segments of DNA.
Option A
<h3><u>Explanation:</u></h3>
Crossing over is an event of Prophase 1 of meiosis 1. It occurs in the zygotene phase of prophase 1. Here the homologous chromosome pairs get very close together and gets packed within protein coat. The enzymes randomly cut the DNA segments from both chromosomes at same loci and exchange them with each other. This results in the exchange of genes between the two chromosomes. This is how the variation comes to place between offsprings of the same individuals. The crossing over results to form X shaped intersections between homologous pair of chromosomes which is called as chaismata. This phase occurs in pachytene phase and is visible in diplotene phase when the protein coat dissolves.
If you mean the change in water Temperature then they simply just go on in life, they are very adaptable creatures.
The correct answer is C.commensalism; parasitism
At first it is a commensalism relationship which becomes parasitic when the living cells get attacked.
Answer:
1.Vascular tube is used for vascular surgery and is very small in size with very small diameter and thickness,thus a little change in environment can also affect there result.
2.When testing for tension in the polymer it is very important to consider the strain rate as the increase in strain can cause the material to break.Therefore not only tension test but also strain test is required.
Explanation:
