When the RNA primers are removed from the 5' ends of eukaryotic chromosomes after replication, DNA polymerase is unable to fill in the gaps. What prevents the chromosomes from getting shorter and shorter with each round of replication?
What will be an ideal response?
The enzyme telomerase maintains chromosome lengths by adding telomere repeats to the chromosome ends. Telomerase contains an RNA component that is complementary to the telomere repeat unit of the chromosome. After binding to the overhanging repeat, the telomerase RNA is used as a template to synthesize new chromosomal telomere repeats.
You might also like to view...
Oxytocin can generate feelings of well-being as well as anxiety and stress
Indicate whether the statement is true or false.
Answer the following statements true (T) or false (F)
1) Crossing-over occurs in meiosis I and meiosis II. 2) Chromosome duplication occurs between meiosis I and meiosis II. 3) In animal cells, cell division is accomplished by the formation of a cleavage furrow. 4) Daughter cells produced in meiosis are identical. 5) Chromosome duplication occurs prior to both mitosis and meiosis.
Both Taenia and Trichinella can be found as cysts embedded in pork muscle. Which of the following statements about these organisms is incorrect?
A. Both helminths can exit the digestive system and migrate to other tissues. B. For both organisms, cyst envelopes are digested in the stomach, releasing the larvae to the intestine. C. Only Taenia can be transmitted from one human to another. D. Both organisms release eggs in the feces to propagate the helminth.
What is a genetic screen?
a. An example would be a biochemical test for enzyme activity. b. A test using phenotypes or genetic makers. c. Is requested by a doctor in response to medical information. d. Are population based and administered to most members of a paricular group.