Answer:
With millions of different kinds of organisms in the world, scientists must find order in all of this diversity. Scientists group living organisms into one or more of a few major categories as part discipline known as taxonomy. The bodies of organisms are organized into functional systems—cells are organized into tissues, and tissues are organized into organs. Body systems carry out critical functions, such as locomotion, reproduction, digestion, and circulation. All living things on Earth are composed of the same carbon-based, molecular building blocks.

Answer:
1. Designing of the target vector.
2. Insertion of the target vector into the embryonic stem cell
3. Selection of the cells
4. Injecting selected cells into the new cells
5. Breeding of mouse with a normal mouse
Explanation:
The target vectors are made by inserting markers into them. The target vector is inserted into ES cells. The vector generally recombined with the target gene and knock-out that gene. Sometimes, recombination of vectors occurs at incorrect place.
The cells survive in the presence of markers only if the target gene is incorporated with target vector. The cells with the target vector are injected into a normal developing embryo of mouse.
The developed mouse will consist of heterozygous knockout cells and its own cells. The normal mouse is bred with this chimeric mouse. The offspring of these mouse are able to transfer knock-out gene to next generation.
we have 300+300+50+350=1000 individuals
400 have the u2 gene
that means 40% or a frequency of 0.4