Biology 1001 Test 3
plant cells have cell walls
Cytokinesis following mitosis differs in animal and plant cells because __________.
telophase
Cytokinesis often, but not always, accompanies ___
DNA double helix, histone, nucleosome, chromatin, chromosome
DNA is compacted and condensed in order to make it easier to proceed through the cell cycle. What is the correct sequence from loosely compacted DNA to highly condensed DNA?
mitotic phase
During _____ both the contents of the nucleus and the cytoplasm are divided.
Interphase
During _____ the cell grows and replicates both its organelles and its chromosomes.
microtubules pushing the poles of the cell apart
During anaphase, the cell becomes more ovoid. This is due to __________
homologous chromosomes; sister chromatids
During meiosis I, __________ separate; during meiosis II, __________ separate.
two chromosomes and four chromatids
During prophase a homologous pair of chromosomes consists of _____
the spindle microtubules attach to the chromosomes
During prophase of mitosis, __________.
once;two
During the process of meiosis, DNA is replicated __________, followed by __________ nuclear division(s).
G2
During what stage of the cell cycle will a cell release Cdks to initiate the events for cell division?
new combinations of alleles
Genetic recombination (crossing over) produces __________.
Genes carry the instructions for making proteins
How do the genes in DNA control cell function?
Three
How many major checkpoints will occur in the eukaryotic cell cycle?
You can't tell whether the DNA has replicated unless the DNA is condensed.
Imagine that you are looking at a eukaryotic cell in the microscope. When you examine the cell's nucleus, you see that the chromatin is spread uniformly through the nucleus—you cannot see chromosomes. Has the cell's DNA been replicated yet? Explain.
metaphase of mitosis or meiosis II
Imagine that you are looking at a eukaryotic cell in the microscope. When you examine the cell, you see that the nucleus is not present and that chromosomes are condensed and lined up independently in single-file in the center of the cell. What possible stage of division might you be observing in this cell?
remain attached at their centromeres
Immediately after replication, the two DNA molecules __________.
the same as in the parent cell
In mitosis, the number of chromosome sets in daughter cells is which of the following?
anaphase, prophase, telophase, centrioles forming
Match the terms with the appropriate stages in the answer: migration, shortening and thickening, cytokinesis, prophase.
telophase
Nuclear envelopes form during __________.
interphase
Nucleoli are present during _____.
chromosome duplication
Prokaryotic fission would NOT occur if which of the following items or processes were missing or not completed properly?
creating new combinations of homologous chromosomes and fusing gametes from two individuals to form a diploid organism
Sexual reproduction produces genetic diversity by __________.
prometaphase
Spindle fibers attach to kinetochores during ____
S phase
The copying of chromosomes occurs during __________.
metaphase
The equatorial plate of the mitotic spindle is formed during what stage?
DNA replication
The first step of bacterial replication is _____.
Interphase
The longest phase of the eukaryotic cell cycle is
Histones
The proteins that coil with DNA producing the "beads on a string," or nucleosomes, are called which of the following?
cells that contain only one of each type of chromosome
The term "haploid" refers to __________.
Prokaryotic Fission
The type of cell division carried out by prokaryotic cells is known as
-the amount of DNA present -whether the DNA is housed in a nucleus or not -whether the DNA is linear or circular
What is different concerning the DNA in bacterial cells as opposed to eukaryotic cells?
They help control the eukaryotic cell cycle.
What is the function of the cyclin-dependent kinases?
mutations in DNA
What is the ultimate source of genetic variability in organisms?
locus
What word is used to describe the exact position of a gene on a chromosome?
both a complete set of chromosomes and cytoplasmic components needed for transcription and translation
When a cell divides, what must it pass on to its offspring?
a chemical that prevents DNA synthesis
Which of the following chemicals would be potentially useful for treating cancer?
Asexual reproduction can occur more quickly than sexual reproduction.
Which of the following is a difference between sexual and asexual reproduction?
The chromosome of a prokaryotic cell is a circular DNA double helix, whereas the chromosomes of eukaryotic cells are linear DNA double helices.
Which of the following statements about the chromosomes of prokaryotic and eukaryotic cells is true?
Sexual reproduction promotes genetic variability, thereby increasing the probability that an individual with new combinations of favorable traits may arise.
Which of the following would be an advantage of sexual reproduction?
animals
Which organism spends most of its life cycle in a diploid state?
fungi and unicellular algae
Which organisms spend most of their life cycle in the haploid state?
centromeres
Which specific structure must separate during anaphase in order for sister chromatids to begin moving toward opposite poles?
The DNA of a prokaryotic cell is contained in a single, circular chromosome about a millimeter in circumference.
Which statement below would be accurate in describing the DNA of a prokaryotic organism?
any cell or organism that is genetically identical to another
A clone is
two linear DNA double helices and two sister chromatids
A duplicated eukaryotic chromosome contains
alleles; mutation
Alternate forms of a particular gene are called __________; they arise as a result of __________.
binary fission
Bacteria divide by:
Stem Cells
Cells that have the characteristics of self-renewal and the ability to differentiate into a variety of cell types are known as
anaphase
Centromeres divide and sister chromatids become full-fledged chromosomes during _____.
prophase
Chromosomes become visible during _____.
one chromosome vs. many chromosomes
Compare prokaryotic cells to eukaryotic cells. Which difference between these two cell types affects cell division the most?
The number of chromosomes
"Meiosis" comes from a Greek word that means "to decrease." What decreases during the process of meiosis?
