The highly repetitive minisatellite DNA regions of the genome are highly polymorphic in the number of copies of the individual repeats among different individuals
They are often used for "fingerprinting" individuals for forensic analysis. Describe how the process of unequal crossing over alters the copy number of these repeats.
What will be an ideal response?
Ans: A recombination event occurs between two copies of the repeat on homologous chromosomes that are not located at the same position in the chromosome (the repeats are not in register with one another). This results in unequal crossing over (also called nonreciprocal recombination), resulting in an increase in the number of copies of the repeat in one chromosome and a decrease in the copy number in the other.
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The nicking of DNA that initiates recombination during mitosis may be due to all of the following EXCEPT
A) instructions from the normal cell cycle program. B) X-rays. C) chemical damage. D) physical damage. E) radiation.
Oxytocin has specific effects on the
a. uterine musculature. b. voluntary muscles throughout the body. c. nervous tissue. d. target cells in the brain. e. target cells in the digestive tract.
The genomes of some vertebrates are much smaller than those of others
For example, the genome of the pufferfish Fugu is much smaller than the human genome, and even much smaller than genomes of other fish, primarily because of the small size of its introns. A. Describe a mechanism that might drive evolution toward small introns or loss of introns and could therefore account for the evolutionary loss of introns according to the "introns early" hypothesis. B. Describe a mechanism that might drive evolution toward more or larger introns and could thereby account for the evolutionary appearance of introns according to the "introns late" hypothesis.