Introduction to Cell Division and Heredity
Cell Division, Heredity, and Rcolution Practice Questions
Cell Division
An organism is heterozygous at two gene loci on different chromosomes.
Explain how these alleles are transmitted by the process of mitosis to daughter cells.
After mitosis the parent cell's genome is dividedninto two daughter cells.
In most eukaryotes, the nuclear envelope that separates the DNA from the cytoplasm disassembles. The chromosomes align themselves in a line spanning the cell. As the cell elongates, corresponding sister chromosomes are pulled toward opposite ends. A new nuclear envelope forms around the separated sister chromosomes. As mitosis completes, cytokinesis is well underway.
Explain how these alleles are distributed by the process of meiosis to gametes.
Meiosis I separates homologous chromosomes, producing two haploid cells.
During Prophase I, synapse and crossing over occurs.
During Metaphase I, Homologous pairs move together along the metaphase plate.
In Anaphase I, Kinetochore microtubules shorten, severing the recombination nodules and pulling homologous chromosomes apart.
In Telophase I, The chromosomes arrive at the poles.
Explain how the behavior of these two pairs of homologous chromosomes during meoisis provides the physical basis for Mendel's two laws of inheritence.
The behavior of these two pairs of homologous chromosomes during meoisis provide the physical basis for Mendel's two laws of inheritence because the Law of Segregation states that when any individual produces gametes, the copies of a gene separate, so that each gamete receives only one copy--either one allele or the other.
According to this "Inheritance Law," alleles of different genes assort independently of one another during gamete formation. Mendel concluded that different traits are inherited independently of each other, so that there is no relation.
Heredity
A person with Turner's Syndrome has a genotype of XO, while a person with Klinefelter's Syndrome has a genotype
Cell Division
An organism is heterozygous at two gene loci on different chromosomes.
Explain how these alleles are transmitted by the process of mitosis to daughter cells.
After mitosis the parent cell's genome is dividedninto two daughter cells.
In most eukaryotes, the nuclear envelope that separates the DNA from the cytoplasm disassembles. The chromosomes align themselves in a line spanning the cell. As the cell elongates, corresponding sister chromosomes are pulled toward opposite ends. A new nuclear envelope forms around the separated sister chromosomes. As mitosis completes, cytokinesis is well underway.
Explain how these alleles are distributed by the process of meiosis to gametes.
Meiosis I separates homologous chromosomes, producing two haploid cells.
During Prophase I, synapse and crossing over occurs.
During Metaphase I, Homologous pairs move together along the metaphase plate.
In Anaphase I, Kinetochore microtubules shorten, severing the recombination nodules and pulling homologous chromosomes apart.
In Telophase I, The chromosomes arrive at the poles.
Explain how the behavior of these two pairs of homologous chromosomes during meoisis provides the physical basis for Mendel's two laws of inheritence.
The behavior of these two pairs of homologous chromosomes during meoisis provide the physical basis for Mendel's two laws of inheritence because the Law of Segregation states that when any individual produces gametes, the copies of a gene separate, so that each gamete receives only one copy--either one allele or the other.
According to this "Inheritance Law," alleles of different genes assort independently of one another during gamete formation. Mendel concluded that different traits are inherited independently of each other, so that there is no relation.
Heredity
A person with Turner's Syndrome has a genotype of XO, while a person with Klinefelter's Syndrome has a genotype