Part 4: Chromosomes and Cell Reproduction Examining Chromosomes: In the late 196
ID: 217078 • Letter: P
Question
Part 4: Chromosomes and Cell Reproduction Examining Chromosomes: In the late 1960's and early 1970's, geneticists developed staining procedures that produce patterns of dark and light bands on each chromosome. When chromosomes are stained with Giemsa, areas with a high concentration of cytosine-guanine (C-G) base pairs turn dark and areds with a high concentration of adenine-thymine (A-T) base pairs remain light. Particular chromosomes of all humans absorb the stain in the same way. The stain produces band patterns that are unique for each of the different chromosomes. For example, chromosome # 1 for all humans has this same pattern of bands. Notice that the chromosome below has an area towards the middle that is narrowed. This is called the centromere. The centromere can be located in the center of the chromosome with arms of equal or very equal length or can be located slightly to one side of the chromosome's center, giving one longer and one shorter arm, near one end. giving arms very unequal in length, or at the very end, giving only one arm. Chromosome banding patterns and centromere location have been used as the basis for a system of identifying specific chromosome regions on each chromosome. These banding and centromere markers allow the geneticist clearly to identify each of the different human chromosomes. The development of banding techniques and related methods has provided researchers with a powerful tool for chromosome studies and comparisons. Chromosome analysis has many important applications in the studies of genetics and evolution. Notice in the chromosome below that the centromere divides the chromosome into two arms. In this system, the short arm of each chromosome is designated the "p" arm and the other is "q Region Band 2 2 3Explanation / Answer
Basic point to notice:::
In the image we can see there are a partition of the chromosome into two arms which are p and q.
Now lets take p, this arm is subdivided into 3 regions and every regions have some bands.
for example, 3rd region of p have 6 bands.
lets solve the questons.
Answer of question 3:
To answer this question count all the number of bands in all regions of p and q.
1st region of p has : 3
2nd region of p has : 2
3rd region of p has : 6
1st region of q has : 2
2nd region of q has: 5
3rd region of q has : 2
4th region of q has : 4
Total no of bands = 3+2+6+2+5+2+4 = 24 Ans
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Answer of question 4:
In giemsa banding C-G rich region becomes dark so count all dark bands.
P arm has 5 dark bands
q arrm has 6 dark bands
so the answer is total number of bands at high concentration of C-G base pair is 5+6 = 11
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Answer of question 5:
Same as previous question but here we have to count Light bands ( lighter sites )
so the answer is total number of bands at high concentration of A-T base pair is 13.
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Answer of question 6:
By the image is can clearly see that p arm is devided into 3 regions.
so answer is 3.
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Answer of question 7
look at the 3rd region of the p arm ( Topest point of image )
there are 6 bands so answer is also 6.