Mastering Biology Ch 7, 11, 12

Front 1

Which molecules do not normally cross the nuclear membrane?

Back 1

DNA

Front 2

the nuclear envelope is continuos with the Golgi apparatus. True or false?

Back 2

False

Front 3

true or false? large proteins containing a nuclear localization signal bind to the nuclear pore and enter the nucleus without any expenditure of energy

Back 3

False

Front 4

a small protein (molecular weight = 25,000 daltons) is injected into a cell and observed in the nucleus a short time later. what type of transport has taken place?

Back 4

passive transport

Front 5

in experiments to test whether a protein can enter the nucleus, why would proteins be labeled with florescent molecules?

Back 5

to make the proteins easy to see

Front 6

Histones are nuclear proteins. two fusion proteins, each consisting of a different segment of histone linked to the same large cytoplasmic protein, are injected into a cell. a short time later, one fusion protein is found in the nucleus and the other is found in the cytoplasm? what conclusion can be drawn from these results? nucleoplasmin is a nuclear protein. this protein was divided into two segments and linked to the same large cytoplasmic protein, generating two fusion proteins. after injecting these fusion proteins into a cell, one of the proteins was found in the nucleus and the other in the cytoplasm. which of the following conclusion can be drawn from these results?

Back 6

only one of the two fusion proteins possesses a nuclear localization signal. only one of the fusion proteins contains a nuclear localization signal.

Front 7

pancreatic cells, which secrete a large amount of digestive enzymes, are labeled with radioactive leucine and then chased for several hours with nonradioactive leucine. photographic emulsions are prepared at different times during the chase. where would the black spots appear on an emulsion prepared 3 hours after the pulse?

Back 7

exterior of the cell

Front 8

what path does a protein in the secretory pathway take, starting from its site of synthesis?

Back 8

rough er, golgi apparatus, secretory vesicles, plasma membrane

Front 9

during a pulse-chase experiment, photographic emulsions were prepared at different times during the chase, and radioactive spots were detected at the following times and locations: 5 mintutes: rough ER. 10 minutes: golgi apparatus. 40 minutes: endosomes. 70 minutes: lysosomes. 140 minutes: lysosomes. what conclusion can be drawn?

Back 9

the final destination of the proteins was lysosome

Front 10

what scientific hypothesis can be tested by a pulse chase experiment?

Back 10

movement of the molecules through a cell over time

Front 11

true or false? proteins produced during the chase phase of a pulse chase experiment are labeled with radioactive material.

Back 11

false

Front 12

what is the first step in a pulse-chase experiment?

Back 12

incubating cells with a labeled molecule

Front 13

which event does not take place before the start of mitosis?

Back 13

the nuclear envelope disintegrates

Front 14

true or false? mitosis takes place during m phase, which is the longest phase of the cell cycle.

Back 14

false

Front 15

which term describes two recently replicated DNA strands that are joined together just before cell division?

Back 15

sister chromatids

Front 16

during which stage of mitosis are chromosomes lined up in the center of the cell?

Back 16

metaphase

Front 17

which stage of mitosis is characterized by the disintegration of mitotic spindles and the formation of two new nuclear membranes?

Back 17

telophase

Front 18

to which part of the centromere do mitotic spindle fibers attach during prometaphase?

Back 18

kinetochore

Front 19

during which substage of mitosis do sister chromatids break apart and start moving to opposite poles of the cell?

Back 19

anaphase

Front 20

what is the function of the S phase in the cell cycle?

Back 20

synthesis of sister chromatids

Front 21

the copying of chromosomes occurs during which phase in the cell cycle?

Back 21

S phase

Front 22

for the first several divisions of early frog embryos, cells proceed directly from the M phase to the S phase and back to the M phase without gaps. what is likely true about diving cells in early frog embryos?

Back 22

the cells get smaller with each generation

Front 23

True or false? The M phase is characterized by the replication and division of a cell's chromosomes.

Back 23

Flase

Front 24

If an organism normally has 34 chromosomes, how many molecules of DNA should there be in the G1 phase of the cell cycle?

Back 24

34

Front 25

Which of the following events would cause the cell cycle to arrest?

Back 25

Poor nutrient conditions

Front 26

What is the ploidy of organisms that have two sets of chromosomes?

Back 26

2n

Front 27

What information can not be obtained from an individual's karyotype?

Back 27

The sequence of bases of a particular gene

Front 28

True or false? A haploid organism has one pair of homologous chromosomes.

Back 28

False

Front 29

True or false? A haploid organism has one pair of homologous chromosomes.

Back 29

False

Front 30

If a cell has 24 chromosomes, how many chromosomes would each of its four daughter cells have after meiosis?

Back 30

12

Front 31

Which of the following statements about meiosis and mitosis is true?

Back 31

Meiosis II is similar to mitosis in that sister chromatids of each chromosome separate.

Front 32

Which structure is directly correlated with the production of genetic variability in the daughter cells produced during meiosis?

Back 32

Chiasma

Front 33

What is the composition of a tetrad at the beginning of prophase I?

Back 33

One pair of homologous chromosomes

Front 34

What is a nondisjunction?

Back 34

An error in cell division that causes homologous chromosomes or sister chromatids to move to the same side of the dividing cell

Front 35

When can nondisjunction occur? Choose the best answer.

Back 35

All three answers are correct.

Front 36

Which syndrome is characterized by the XO chromosome abnormality?

Back 36

Turner syndrome

Front 37

What kind of cell results when a diploid and a haploid gamete fuse during fertilization?

Back 37

A triploid cell

Front 38

Of the following chromosomal abnormalities, which type is most likely to be viable in humans?

Back 38

Trisomy

Front 39

If a diploid cell undergoes meiosis and produces two gametes that are normal, and one with n− 1 chromosomes, and one with n + 1 chromosomes, what type of error occurred?

Back 39

A nondisjunction error occurred in meiosis II, in which both sister chromatids of a chromosome migrated to the same pole of the cell.

Front 40

If a diploid cell undergoes meiosis and produces two gametes with n + 1 chromosomes and two gametes with n− 1 chromosomes, what type of error occurred?

Back 40

A nondisjunction error occurred in meiosis I, in which both members of a homologous pair migrated to the same pole of the cell.

Front 41

What kind of cell results when a diploid and a haploid gamete fuse during fertilization?

Back 41

A triploid cell

Front 42

Of the following chromosomal abnormalities, which type is most likely to be viable in humans?

Back 42

Trisomy

Front 43

If a diploid cell undergoes meiosis and produces two gametes that are normal, and one with n− 1 chromosomes, and one with n + 1 chromosomes, what type of error occurred?

Back 43

A nondisjunction error occurred in meiosis II, in which both sister chromatids of a chromosome migrated to the same pole of the cell.

Front 44

If a diploid cell undergoes meiosis and produces two gametes with n + 1 chromosomes and two gametes with n− 1 chromosomes, what type of error occurred?

Back 44

A nondisjunction error occurred in meiosis I, in which both members of a homologous pair migrated to the same pole of the cell.