homework

Question 1

which gene is responsible for dosage compensation in placental mammals?

Answer 1

Xist

Question 2

what is the name of the protein complex that facilitates chromosome movement and division during M phase?

Answer 2

kinetochore

Question 3

the __________ __________ is a cell structure consisting of microtubules, which forms during early mitosis and plays a role in cell division

Answer 3

mitotic spindle

Question 4

is DNA content doubled at end of M phase?

Answer 4

yes

Question 5

what would happen to acentric chromosomes (lack centromere) during cell division?

Answer 5

• daughter cells will receive either 2 copies of the centrist chromosome or no copies at all
• acentric chromosomes move randomly to one pole or other

Question 6

what would happen to dicentric chromosomes (two centromeres) during cell division?

Answer 6

• daughter cells would receive fragments of dicentric chromosomes
• pulled in opposite directions during cell division and can break as result

Question 7

which of the following is not a factor in the regulation of cell division in normal cells?
a. growth-inhibiting factors promote synthesis of proteins that inhibit cell division
b. growth factors enter cell nucleus
c. transcription factors recruited
d. signals transducer from cell surface to cell nucleus

Answer 7

b. growth factors enter the cell nucleus

Question 8

which statement correctly describes regulation of cell division?
a. transcription of growth-promoting genes is enhanced by growth factors and inhibited by growth-inhibiting factors
b. cells divide when division is favored by sum of multiple signals
c. given cell displays receptors for and responds to either growth or growth-inhibiting factors
d. cells will divide continuously unless they encounter an inhibitory signal

Answer 8

b. cells divide when division is favored by sum of multiple signals

Question 9

The binding of extracellular growth factors to cell surface receptors ultimately results in the expression of a specific gene or genes. This fact suggests all of the following except that​ _______.
a. the initial signal is relayed to the cell nucleus
b. the signal cannot be turned off
c. factors influencing a​ cell’s “decision” to divide are initiated outside the cell
d. these receptors span the cell membrane

Answer 9

b. the signal cannot be turned off

Question 10

which condition is evaluated at the G2/M checkpoint

Answer 10

precise replication of DNA

Question 11

is DNA content halved in meiosis I or II?

Answer 11

both

Question 12

how many different phenotypes are possible in a one gene/three allele system that displays codominance?

Answer 12

6

Question 13

true or false: the color dilution gene in horses is an example of incomplete dominance

Answer 13

true

Question 14

prototrophs

Answer 14

can grow on minimal media/amino acids

Question 15

auxotrophs

Answer 15

cannot grow on minimal media

Question 16

__________ ____________ indicates that less than 100% of ind. w/ a mutant genotype have the mutant phenotype

Answer 16

incomplete penetrance

Question 17

____________ ____________ indicates that the severity of a mutant phenotype differs among ind. w/ the mutant genotype

Answer 17

variable expressivity