The ends of the linear chromosomes of eukaryotes cannot be replicated by DNA polymerase. This problem is overcome through the use of telomerase, an enzyme implicated in aging and cell lifespan. Telomerase contains a noncoding RNA that acts as a moving template to add a repetitive DNA sequence at the chromosome tip, preventing the loss of essential DNA. In mammals, the ends of the chromosomes fold back to form a circular structure called a T‑loop.

Select the answers that correctly describe telomeres and the actions of telomerase.

a. Telomerase is a specialized reverse transcriptase and its presence within eukaryotic cells indicates that an early eukaryote was infected by a retrovirus.
b. Inappropriate activation of telomerase can result in cellular immortality, one of the cellular changes implicated in the development of cancer.
c. Telomerase activity is turned off in most human cells, causing the telomeres to gradually shorten as the individual ages.
d. The T-loop protects the chromosome ends from degradation by nucleases and double strand break repair enzymes.
e. Telomerase activity results in a telomere that is completely double-stranded with no single stranded region that would be susceptible to nucleases.

Some technological solutions to problems like global warming meet the specific needs and situations of local communities. an example from india involves converting the solid waste from cattle into clean-burning fuel for cooking. this reduces the amount of greenhouse gases, specifically methane and carbon dioxide, released into the environment from wood fires. when evaluating the feasibility of implementing this solution, computer models are used to weigh costs against benefits. what factor is least likely to impact the decision on adopting this technology?

Will mark brainliest i only need the ! 1.use ten beads and a centromere of one color to construct the long chromosome. use ten beads and a centromere of a second color to construct the second chromosome in the long pair. make a drawing of the chromosomes in the space below. 2. for the second pair of chromosomes, use only five beads. 3. now model the replication of the chromosomes. make a drawing of your model in the space below. part b: meiosis i during meiosis i, the cell divides into two diploid daughter cells. 4. pair up the chromosomes to form tetrads. use the longer tetrad to model crossing-over. make a drawing of the tetrads in the space below. 5. line up the tetrads across the center of your “cell.” then model what happens to the chromosomes during anaphase i. 6. divide the cell into two daughter cells. use the space below to make a drawing of the result. part c: meiosis ii during meiosis ii, the daughter cells divide again. 7. line up the chromosomes at the center of the first cell, one above the other. separate the chromatids in each chromosome and move them to opposite sides of the cell. 8. repeat step 7 for the second cell. 9. divide each cell into two daughter cells. use the space below to make a drawing of the four haploid cells

The picture showed normal blood cells which are around and sickle cells which appear much longer people with sickle-cell suffer from the sickle cell anemia which is inherited diseaseit is caused by a change in gene responsible for production of hemo goblin this type of change is known as an