Unit 7 Bio Test Flashcards
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
A) chromatin condensing into chromosomes
What is a karyotype?
a display of every pair of homologous chromosomes within a cell, organized according to size and shape
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
5,2,4,3,1
What step in meiosis is also in mitosis?
separation of sister chromatids
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
B) synapsis of chromosomes
In animals, meiosis results in gametes, and fertilization results in ___________.
zygotes
In which stage of meiosis do the centromeres of sister chromatids disjoin and the chromatids themselves separate?
anaphase 2
In which stage of meiosis do the tetrads of chromosomes align at the equator of the spindle; alignment determines independent assortment?
metaphase 1
In which stage of meiosis does synapsis of homologous pairs occur; crossing over may occur?
prophase 1
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?
the controls on cell growth and division can be turned on and off
The daughter cells of binary fission are ____________.
genetically identical
Asexual reproduction results in identical offspring unless what occurs?
crossing over
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
E) A, B, and C
An advantage of sexual reproduction over asexual reproduction is that sexual reproduction ________________.
provides genetic diversity
If there are 20 chromatids in a cell, how many centromeres are there?
10
After telophase 1 of meiosis, the chromosomal makeup of each daughter cell is ______________.
haploid, and the chromosomes are each composed of two chromatids
Nondisjunction can occur in meiosis 1 and/or meiosis 2. What haploid cell would result if nondisjunction occurred during anaphase of meiosis 1?
two cells with n+1 chromosomes, and two cells with n-1 chromosomes
A human cell containing 22 autosomal and a Y chromosome is ___________.
a sperm
Why do chromosomes coil during mitosis?
to allow the chromosomes to move without becoming entangled and breaking
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?
the drug blocks the spindle fibers from forming therefore mitosis can not occur
What does NOT happen during mitosis?
production of diploid cells
If there are 12 chromosomes in an animal cell in the G1 stage, what is the haploid number of chromosomes for this organism?
6
Cancer cells divide uncontrollably and often send chemical signals causing blood vessels to grow towards them and provide nutrients. This process is called _______________.
angiogenesis
What is the difference between a benign and a malignant tumor?
benign tumors don’t metastasize; malignant tumors do
