Answer:
Telomerase acts to elongate the 3' end of linear DNAs.
Explanation:
The 5' ends of the linear DNA can not be replicated by DNA polymerase due to the absence of free 3' end to be elongated. This is prevented by the action of telomerase enzyme which contains both RNA and protein components. The RNA component of the telomerase is 150 nucleotides long.
The telomerase enzyme elongates the 3' end of the template strand by using its inbuilt RNA template. Since it uses an RNA template to make the DNA copies, it is a reverse transcriptase. Repeated translocation and repositioning of the enzyme elongates the 3' end of the template DNA.
The RNA primase makes the RNA primer at the end of the new telomere strand which is then elongated by DNA polymerase. DNA ligase seals the nick. In this way, telomerase serves to prevent the loss of 5' ends of linear DNA in successive rounds of DNA replication.
Answer:
The right answer is intercalated discs.
Explanation:
If you observe cardiac muscles under a microscope, the first feature that appears is Intercalated discs. Cardiac muscles contains heart muscle cells which are called as cardiomyocytes which are linked by these discs to perform a single functional organ.
Intercalated discs helps in harmonizing the contraction of cardiac tissues.
Answer:
Stimulation of the parasympathetic nervous system results in: Construction of pupils. Decreased heart rate and blood pressure.
Explanation:
Answer:
The protection of internal environment from the harms of fluctuations in external environment is termed as HOMEOSTASIS.
Explanation:
External environment and its component fluctuate continuously, however, the organism resists and manage these changes by making adjustments to keep its own internal fluctuations within a narrow range thus protecting internal environment from harms of fluctuations.
CITES work by subjecting international trade though Licensing System.
<u>Explanation:</u>
Approximately, 30000 species of Plant and 5800 animal species are under Protection by CITES against over exploitation through international trade. Flora and Fauna species are grouped in three appendices depending on how much they are threatened by International trade. CITES works by subjecting. To certain control, CITES used to subject international trade of specimen of certain species. There are applicable licensing system which is controlled or monitored by management authorities and scientific authorities. Role of Scientific authorities to advise effect of trade on species status.
All Export, Import, re export of these species should be authorized by Licensing system
Appendix I species are endanger of extinction and their trade permitted on exceptional situation.
Appendix II species are not in endanger of extinction but their trade need to be controlled to avoid species utilization that are unsuited with their survival
Appendix III contain those species which are endangered in at least one country and these are asked with CITES parties for helping in controlling their trade
