BIO204: meiosis and mitosis
What is true about mitosis??
Crossing over occurs during prophase.
The four haploid nuclei found at the end of meiosis differ from one another in their exact genetic composition. Some of this difference is the result of
crossing over during prophase I.
All zygotes are
diploid.
What is the final result of mitosis?
genetically identical 2n somatic cells
At the end of mitosis, each daughter cell has:
identical DNA to that of the parent cell
Meiosis can occur
in all sexually reproducing organisms.
The second meiotic division of meiosis is important because
it allows for crossing over and random distribution of chromosomes.
Chromosome number is reduced during meiosis because the process consists of
two cell divisions and only a single round of chromosome replication
The products of mitosis are
two genetically identical cells.
A parent cell divides to form two genetically identical daughter cells in the process of mitosis. For mitosis to take place:
. The parent cell must divide its DNA in half so each daughter cell gets only the genes needed to carry out its functions. In this way, differentiation occurs.
For a species such as Homo sapiens with a haploid number of 23 chromosomes, how many different combinations of maternal and paternal chromosomes are possible for the gametes?
92, 23^2
What is the fundamental difference between mitosis and meiosis?
The number of chromosomes doubles in meiosis; it stays the same in mitosis.
Which statement about the daughter cells of mitosis is correct?
They are genetically identical to one another and to the parent cell.
Which of the following statements about homologous chromosome pairs is false?
They come from only one of the individual's parents.
What is a tetrad?
a group of four chromatids produced when homologs synapse
a cell
a. can be composed of many types of tissues. b. is found only in plants and animals. c. is the smallest entity studied by biologists. d. may be a distinct entity or a building block of a more complex organism. e. All of the above
Homologous chromosomes _____.
are identical
What are homologous chromosomes?
chromosomes that are similar in their size, shape, and gene content
In human cells, chromosomes are
connected by centromeres, except for the X and Y.
A haploid cell is a cell
containing only one copy of each chromosome
At which stage in meiosis is chromosome number typically reduced from 2n to n?
meiosis II
Homologous chromosomes move to opposite poles of a dividing cell during
mitosis
Asexual reproduction produces genetically identical individuals because
no meiosis or fertilization take place.
The major drawback of asexual reproduction is that it
produces less variation among offspring than does sexual reproduction.
Genetic recombination occurs during
prophase of meiosis I.
A mechanism for increasing the genetic diversity of offspring is
sexual reproduction.
Meiosis II is similar to mitosis in that:
sister chromatids separate during anaphase
The total DNA content of each daughter cell is reduced during meiosis because
sister chromatids separate during anaphase of meiosis I.
One difference between mitosis and meiosis I is that
sister chromatids separate during meiosis but not during mitosis.
A key difference between mitosis and meiosis is:
synapsis of homologous chromosomes in meiosis
Sexual reproduction increases genetic variability through
the exchange of genetic information between male and female gametes during meiosis I.
what is meant by a paternal chromosome?
the member of a homologous pair that was inherited from the father
what is genetic recombination?
the new combination of maternal and paternal chromosome segments that results when homologs cross over
A parent cell divides to form two genetically identical daughter cells in the process of mitosis. For mitosis to take place _____.
the parent cell must divide its DNA in half so that each daughter cell gets only the genes it needs
Each diploid cell of a human female contains _______ of each type of chromosome.
two