helper t cells may activate b cells, while suppressor t cells inhibit the activity of b cells
sorry it took so long
Answer/Explanation:
(1) a mutation in the coding region, resulting in an inactive protein
To check to see if there is a mutation, you could extract the DNA from the cancer cells and then perform PCR to amplify the gene of interest. You could then perform sanger sequencing and compare the sequence to the normal gene to see if a mutation is present. To test the effect of the mutation, you would want to see if an active protein has been formed.
To see if a normal sized protein has been formed, you could perform a western blot, comparing the protein band to the WT protein band. If the protein is absent or much smaller, it is likely not a functional protein.
(2) epigenetic silencing at the promoter of the gene, resulting in reduced transcription.
To check for changes in the epigenetic landscape of the promoter, you could perform chromatin immunoprecipitation by extracting the chromatin from the tumour cells and using antibodies for different chromatin marks to see what has changed between the normal cells and the tumor cells. E.g. H3K9me3, H3K27me3. You would perform a pull down with the antibody of interest and then PCR for your promoter to specifically look at changes at that gene compared to normal cells. To test DNA methylation, you could perform bisulfite sequencing.
To see how transcription is affected, you could extract RNA from the tumor and normal cells, and compare the levels of RNA between the two samples by qRT-PCR
On the basis of the principle of complementary base pairing, you would expect the percentage of Purines in an individual's DNA to be equal to the percentage of Pyrimidines.
<h2>Further Explanation: </h2><h3>DNA </h3>
- DNA is a nuclei acid that is responsible for carrying genetic information in living organisms.
- It is through DNA that genetic information is passed from one organism to another through the process of DNA replication.
- Additionally, it carries the information that is used to make proteins which performs various functions in living cells.
- Each Nucleotide in DNA contains a nitrogenous base, a deoxyribose sugar, and a phosphate group.
- DNA molecules are made up of nitrogenous bases; Adenine, Guanine, Cytosine and Thymine.
<h3>Base pairing </h3>
- A DNA molecule exists as a double helix with two strands that are formed as a result of pairing between complimentary bases on the two strands.
- Purine bases bonds to complementary pyrimidine bases. This happens because the shapes of purine and pyrimidine bases allow hydrogen bonds to form between the two.
<h3>Chargaff's rule </h3>
- According to Chargaff's rule the DNA of any cell or organism must have a ratio of 1:1 between purine bases and pyrimidine bases such that the amount of guanine is equal to the amount cytosine, and that the amount of adenine is equal to the amount of thymine.
- According to the rule rule states that adenine pairs only with thymine and guanine pairs only with cytosine.
- Two hydrogen bonds form between an adenine and thymine base pair, whereas three hydrogen bonds form between a guanine and cytosine base pair.
Keywords: Nucleic acids, DNA, nitrogenous bases, Base pairing, Chargaff's rule.
<h3>Learn more about: </h3>
Level: High school
Subject; Biology
Topic; Nucleic acids
Sub-topic: RNA and DNA structure
If two populations of birds stop interbreeding because of a difference in song patterns this would be described as behavioral isolation.
Answer:
Meristematic tissue.
Explanation:
Meristematic tissue contains stem cells which can differentiate into permanent cells. This tissue is at all continuous growth points in a plant, at the apical buds ( where leaves and flowers form) and at the ends of roots.
- dermal tissue is in animals - this refers to the tissues associated with skin
- vascular tissue refers to the xylem and phloem of a plant- no growth occurs here.
- Permanent tissue is tissue which has already differentiated and grown. This is the final form.