2 5
9. Which genes do you predict would be on or off for a nerve cell? Write your prediction in the
diagram below!
Nerve cell
ID TID UUDIIDID ID CIDLIDI
Part II: Environmental Factors That Affect Gene Expression
You now know that all the DNA in every cell of your body is the same. When genes are turned
on or off, they determine the types of cells that will form and the types of traits that will be
expressed in an organism. Environmental factors can also play a role in gene expression. For
example, the expression of hair color in the snowshoe hare is affected by temperature. The
int that gives the hare a brown-grey

rising sea temps which are causing coral reefs to bleach and die out

glaciers are melting causing sea levels to rise wgich could flood out land

explanation:

9.9 years

a = p(1 + rt) . . account balance after time t at rate r starting with principal p

3000 = 2500(1 + 0.0202t) . . filling in the given numbers

1.2 = 1 + 0.0202t . . divide by 2500

0.2 = 0.0202t . . . subtract 1

0.2/0.0202 = t ≈ 9.901

it will take about 9.9 years for the account balance to reach $3000.

interphase

the period of cell growth when the cell synthesizes new molecules and organelles. the cell is not dividing and it constitutes the majority of the time spent in the cell cycle

prophase

changes occur in the nucleus and cytoplasm. the chromatin condenses to form structures (sister chromatids) visible with a light microscope and the mitotic spindle begins to form, but the nucleus is still in tact

prometaphase

the nuclear envelope fragments and the spindle microtubules attach to the kinetochores of the sister chromatids

metaphase

all the cell's duplicated chromosomes are lined up at an imaginary plane equidistant between the poles of the mitotic spindle

anaphase

begins when sister chromatids separate from each other and ending when a complete set of daughter chromosomes arrives at each of the two poles of the cell

telophase

the daughter nuclei form at the two poles of a cell

cytokinesis

the division of a cytoplasm to form two separate daughter cells. usually occurs during telophase during mitosis. this and mitosis make up to mitotic (m) phase of the cell cycle

b a mature ovary of a plant.