Answer:
D. The two students who have two fragments have one restriction site in this region.
Explanation:
The DNA samples from the cheek cells were subjected to digestion with a restriction enzyme. This enzyme is an endonuclease and cuts the DNA at a specific sequence only. This sequence is called a restriction site. If the restriction site is not present in the sample DNA, the restriction enzyme cannot cut it. The presence of one restriction site in the sample DNA would cut it into two DNA fragments.
Similarly, the presence of two restriction sites in each DNA molecule would obtain a total of three DNA fragments per DNA molecule.
Differential gene expression patterns allow one tissue to produce a hormone, and another to facilitate nutrient exchange. The same organ can serve both functions because it can synthesize different proteins.
<h3>Diferential gene expression</h3>
Gene expression refers to the differential process by which different genes are expressed (transcribed and then translated) in different cell types.
Gene expression enables different functions due to the production of different types of proteins which may have both enzymatic and structural functions.
A specialized cell type or organ can synthesize different proteins and also generate other molecules (either enzymes or structural proteins) due to the process of cell differentiation.
Learn more about gene expression here:
brainly.com/question/3533860
The anterior rami of the brachial plexus are the continuations of the anterior rami of spinal nerves C5-T1 . These rami emerge from the intervertebral foramina and travel through the neck. The five rami unite to form the superior, middle, and inferior trunks in the posterior triangle of the neck. Nerves C5, C6 unite to form the superior trunk; nerve C7 remains as the middle trunk; and nerves C8,T1 unite to form the inferior trunk. Portions of each trunk divide deep to the clavicle into an anterior and a posterior division. These primarily contain axons that innervate the anterior and posterior parts of the upper limb. Upon reaching the axilla, they converge to form three cords.
Answer:
B
Explanation:
Cytoplasm is like air in the city analogy
In the nucleus of each cell, the DNA molecule is packaged into thread-like structures called chromosomes. Each chromosome is made up of DNA tightly coiled many times around proteins called histones that support its structure.
Chromosomes are not visible in the cell’s nucleus—not even under a microscope—when the cell is not dividing. However, the DNA that makes up chromosomes becomes more tightly packed during cell division and is then visible under a microscope. Most of what researchers know about chromosomes was learned by observing chromosomes during cell division.
