AP BIOLOGY

Detailed explanation-1: -Telomeres are structures made from DNA sequences and proteins found at the ends of chromosomes. They cap and protect the end of a chromosome like the end of a shoelace. In almost all animals, from the simplest to the most complex, telomeres are required for cell division.

Detailed explanation-2: -Why do chromosomes have telomeres? Without telomeres, the main part of the chromosome-the part with genes essential for life-would get shorter each time a cell divides. So telomeres allow cells to divide without losing genes. Cell division is necessary for growing new skin, blood, bone, and other cells.

Detailed explanation-3: -Telomerase adds complementary RNA bases to the 3′ end of the DNA strand. Once the 3′ end of the lagging strand template is sufficiently elongated, DNA polymerase adds the complementary nucleotides to the ends of the chromosomes; thus, the ends of the chromosomes are replicated.

Detailed explanation-4: -A telomere is a region of repetitive DNA sequences at the end of a chromosome. Telomeres protect the ends of chromosomes from becoming frayed or tangled. Each time a cell divides, the telomeres become slightly shorter. Eventually, they become so short that the cell can no longer divide successfully, and the cell dies.