Two-year-old Sam's limited vocabulary consists of words like ...

[madam-professor]

Two-year-old Sam's limited vocabulary consists of words like book, dog, and hat.. Apparently, Sam
 
  a. has a referential style.
 b. is nonsymbolic.
 c. has an expressive style.
 d. is unable to use phonemes

Question 2

A friend of yours wonders out loud, I wonder why we grow older? Enlighten them by comparing and contrasting the rate-of-living, cellular, and programmed cell death theories of aging. In your discussion, be sure to describe the role of telomeres, cross-linking, and free radicals in the process.
 
  What will be an ideal response?

[hollysheppard095]

Answer to Question 1

a

Answer to Question 2

The rate-of-living theory postulates that organisms have only so much energy to expend in a lifetime. The rate of a creature's metabolism is related to how long it lives. The three cellular theories state that aging occurs at the cellular level. The first postulates that the number of times that cells can divide limits the life span. Telomeres are the tips of chromosomes that play a major role in aging by adjusting the cell's response to stress and growth stimulation based on cell divisions and DNA damage. A second cellular theory is based on a process called cross-linking, in which certain proteins in human cells interact randomly and produce molecules that are linked in such a way as to make the body stiffer. A third type of cellular theory proposes that aging is caused by unstable molecules called free radicals, which are highly reactive chemicals produced randomly in normal metabolism. Programmed-cell-death theories propose that aging is programmed into our genetic code. Programmed cell death appears to be a function of physiological processes, the innate ability of cells to self-destruct, and the ability of dying cells to trigger key processes in other cells.

[madam-professor]

Excellent

[carojassy25]

Gracias!