Unit 7 Bio Test

Question 0

Which of the following does NOT occur during interphase?
A) chromatin condensing into chromosomes
B) cell growth
C) DNA synthesis
D) replication of DNA and organelles

Answer 0

A) chromatin condensing into chromosomes

Question 1

What is a karyotype?

Answer 1

a display of every pair of homologous chromosomes within a cell, organized according to size and shape

Question 2

Put these essential steps in meiosis in order to logically illustrate it’s sequence

1) formation of four new nuclei, each with half the chromosomes present in the parental nucleus
2) alignment of tetrads at the metaphase plate
3) separation of sister chromatids
4) separation of homologues; no uncoupling of the centromere
5) synapsis; chromosomes moving to the middle of the cell in pairs

Answer 2

5,2,4,3,1

Question 3

What step in meiosis is also in mitosis?

Answer 3

separation of sister chromatids

Question 4

Which of the following occurs in meiosis but not in mitosis? 
A) production of daughter cells 
B) synapsis of chromosomes 
C) alignment of chromosomes at equator 
D) chromosome replication 
E) condensation of chromatin

Answer 4

B) synapsis of chromosomes

Question 5

In animals, meiosis results in gametes, and fertilization results in ___________.

Answer 5

zygotes

Question 6

In which stage of meiosis do the centromeres of sister chromatids disjoin and the chromatids themselves separate?

Answer 6

anaphase 2

Question 7

In which stage of meiosis do the tetrads of chromosomes align at the equator of the spindle; alignment determines independent assortment?

Answer 7

metaphase 1

Question 8

In which stage of meiosis does synapsis of homologous pairs occur; crossing over may occur?

Answer 8

prophase 1

Question 9

Cells grown in a petri dish tend to divide until they form a thin layer covering the bottom of the dish. If cells are removed from the middle layer of the dish, the cells bordering the open space will begin dividing until they have filled the empty space. What does this experiment show?

Answer 9

the controls on cell growth and division can be turned on and off

Question 10

The daughter cells of binary fission are ____________.

Answer 10

genetically identical

Question 11

Asexual reproduction results in identical offspring unless what occurs?

Answer 11

crossing over

Question 12

Which of the following is true concerning cancer cells?
A) they do not exhibit density-dependent inhibition when growing in culture
B) when they stop dividing, they do so at random points in cell cycle
C) they are not subject to cell cycle controls
D) B and C only
E) A, B, and C

Answer 12

E) A, B, and C

Question 13

An advantage of sexual reproduction over asexual reproduction is that sexual reproduction ________________.

Answer 13

provides genetic diversity

Question 14

If there are 20 chromatids in a cell, how many centromeres are there?

Answer 14

10

Question 15

After telophase 1 of meiosis, the chromosomal makeup of each daughter cell is ______________.

Answer 15

haploid, and the chromosomes are each composed of two chromatids

Question 16

Nondisjunction can occur in meiosis 1 and/or meiosis 2. What haploid cell would result if nondisjunction occurred during anaphase of meiosis 1?

Answer 16

two cells with n+1 chromosomes, and two cells with n-1 chromosomes

Question 17

A human cell containing 22 autosomal and a Y chromosome is ___________.

Answer 17

a sperm

Question 18

Why do chromosomes coil during mitosis?

Answer 18

to allow the chromosomes to move without becoming entangled and breaking

Question 19

Vinblastin is a drug that interferes with the assembly of microtubules. It is widely used for chemotherapy in treating cancer patients whose cells are actively dividing to form tumors. How do you think Vinblastin slows tumor growth?

Answer 19

the drug blocks the spindle fibers from forming therefore mitosis can not occur

Question 20

What does NOT happen during mitosis?

Answer 20

production of diploid cells

Question 21

If there are 12 chromosomes in an animal cell in the G1 stage, what is the haploid number of chromosomes for this organism?

Answer 21

6

Question 22

Cancer cells divide uncontrollably and often send chemical signals causing blood vessels to grow towards them and provide nutrients. This process is called _______________.

Answer 22

angiogenesis

Question 23

What is the difference between a benign and a malignant tumor?

Answer 23

benign tumors don’t metastasize; malignant tumors do

Question 24

How do the daughter cells at the end of mitosis and cytokinesis compare with their parent cell when it was in G1 of the cell cycle?

Answer 24

the daughter cells have the same amount of chromosomes and the same amount of DNA

Question 25

In eukaryotic cells, the timing of the cell cycle is regulated by proteins called _________.

Answer 25

cyclin

Question 26

Oncogenes are mutated genes that ____________.

Answer 26

were originally proto-oncogenes and do not listen to cell signals and continue cell division; like a gas pedal in a car stuck down

Question 27

Chromosomes form tetrads during ___________.

Answer 27

prophase 1 of meiosis

Question 28

The somatic cells derived from a single-celled zygote divide by which process?

Answer 28

mitosis

Question 29

If a p53 is mutated, the cell will _________.

Answer 29

continue to divide

Question 30

If cells in the process of dividing are subjected to colchicine, a drug that interferes with the functioning of the spindle apparatus, at which stage will mitosis be arrested?

Answer 30

metaphase

Question 31

What is the role of the spindle fibers during mitosis?

Answer 31

they help separate sister chromatids

Question 32

How can a gene be mutated with no resulting change in the protein that is produced from that gene?

Answer 32

A codon has changed, but it codes for the same amino acid as the original codon

Question 33

Which is true of a species with the chromosome number of 2n=16?
A) the species is diploid with 32 chromosomes per cell
B) each cell has 8 homologous pairs
C) the species has 16 sets of chromosomes per cell
D) during the S phase of the cell cycle there will be 32 separate chromosomes

Answer 33

B) each cell has 8 homologous pairs

Question 34

Starting with a fertilized egg(zygote), a series of five cell divisions would produce an early embryo with how many cells?

Answer 34

16

Question 35

Besides the ability of some cancer cells to overproliferate (divide too much), what else could logically result in a tumor?

Answer 35

lack of appropriate cell death

Question 36

The human X and Y chromosomes ____________.

Answer 36

include genes that determine an individual’s sex

Question 37

What kind of mutation occurs when one base is changed to another at a single location on the DNA?

Answer 37

substitution (point)

Question 38

Cell reproduction in prokaryotic cells differ from eukaryotic cells in that ______________.

Answer 38

each prokaryotic cell has a circular chromosome but the chromosomes of eukaryotic cells are linearly condensed into chromosomes

Question 39

A cell containing 92 chromatids at metaphase of mitosis would, at its completion, produce two nuclei each with how many chromosomes?

Answer 39

46

Question 40

A “mini gene” allele has the following sequence:
TACCCGTGCACG

What would be the consequence if the first nucleotide of the sequence was deleted?

Answer 40

all of the codons after that point will be changed

Question 41

The fusion of vesicles from the Golgi across the middle of a cell and nuclei are re-forming at opposite ends of the cell. What kind of cell is this?

Answer 41

a plant cell undergoing cytokinesis

Question 42

Independent assortment of the chromosomes is a result of ___________.

Answer 42

the random and independent way in which each pair of homologous chromosomes lines up at the metaphase plate during meiosis 1

Question 43

Chiasmata are what we see under the microscope hat let us know that what occurred?

Answer 43

crossing over

Question 44

During normal mitosis cell division, a parent cell that has four chromosomes will produce two daughter cells, each containing _________.

Answer 44

four chromosomes