1.      Complete the text then listen to the recording and check (timing 1:04-1:55)


                                               The human body is made up of many ______________
which are made of many types of  ______________   These ______________ are made of individual units
called ______________. Each of these ______________ contains 46 ______________ 23 inherited from
each of your parents. ______________ contain segments that are called ______________. Each
______________ contains specific information that makes us unique. The ______________ is made of
______________ through a set of complex instructions. ______________ directs the body to make
______________ They are used to make and run our body ______________.

                             http://www4.utsouthwestern.edu/cellbio/shay-wright/intro/sw_intro.html

2.      Check the pronunciation


telomere

          /'tɛl ə,mɪər, 'ti lə‑/

                                 chromosome

                                                 /'kroʊ mə,soʊm/

enzyme

          /'ɛn zaɪm/

                                 apoptosis

                                                 /āp'əp-tō'sĭs, āp'ə-tō'-/

telomerase

          /tə'lɒm ə,reɪs; ‑,reɪz/

                                 senescent

                                                 /sɪ'nɛs ənt/

protein

          /'proʊ tin; -ti ɪn/

                                 senescence

                                                 /sĭ-něs'əns/

chromosome

          /'kroʊ mə,soʊm/

                                 template

                                                 /'tɛm plɪt/

inhibit

          /ɪn'hɪb ɪt/

                                 arteriosclerosis

                                                 /ɑr,tɪər i oʊ sklə'roʊ sɪs/

ulcer

          /'ʌl sər/

                                 plaque

                                                 /plæk/


3.      True or False?


a.       Telomere is the segment of DNA that occurs at the ends of chromosomes.


b.      In reproductive cells the telomere shortens occasionally.


c.       Telomeres function by helping chromosomes to lose base pair sequences at their ends. Each
time a cell divides, some of the telomere is lost.


d.      When the telomere becomes too long, the chromosome reaches a "critical length" and can no
longer replicate.


e.       Telomerase is an enzyme that causes telomeres to lengthen, facilitates cell division and
may account for the mortality of cancer cells.


f.        Telomerase activity is regulated during development and has a very low, almost
undetectable activity in somatic (body) cells. Because these somatic cells do not regularly use
telomerase, they age.


g.       If telomerase is activated in a cell, the cell will continue to grow and divide.


h.       Telomerase – enzyme works in harmony with the telomere clock in the cell.



4.      Watch the video and check your answers. (timing 1:55–5:08, 6-6:54)
http://www4.utsouthwestern.edu/cellbio/shay-wright/intro/sw_intro.html