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- https://bio.libretexts.org/Bookshelves/Introductory_and_General_Biology/Biology_(Kimball)/07%3A_Cell_Division/7.07%3A_MeiosisThis page covers meiosis, a crucial process in sexual reproduction that produces four haploid cells from one diploid cell, involving two divisions and featuring genetic recombination and chromosome as...This page covers meiosis, a crucial process in sexual reproduction that produces four haploid cells from one diploid cell, involving two divisions and featuring genetic recombination and chromosome assortment for diversity. It highlights the importance of checkpoints to prevent errors, which, if present, can lead to chromosomal abnormalities such as monosomy, often lethal, and trisomy, which can result in conditions like Down syndrome.
- https://bio.libretexts.org/Bookshelves/Introductory_and_General_Biology/Biology_(Kimball)/19%3A_The_Diversity_of_Life/19.01%3A_Eukaryotic_Life/19.1.11%3A_Drosophila_MelanogasterThis page outlines the advantages of using Drosophila (fruit flies) in genetic studies, highlighting their small size, rapid life cycle, and high reproduction rates which support statistically signifi...This page outlines the advantages of using Drosophila (fruit flies) in genetic studies, highlighting their small size, rapid life cycle, and high reproduction rates which support statistically significant results. It mentions the presence of giant polytene chromosomes in larvae for structural analysis, the external development of embryos for easy observation, and the small genome that allows for targeted mutations, all contributing to their effectiveness in research.
- https://bio.libretexts.org/Courses/City_College_of_San_Francisco/Introduction_to_Genetics/03%3A_Meiosis_-_Sexual_Reproduction/3.05%3A_Comparing_Meiosis_and_MitosisThis page details the differences between mitosis and meiosis, two types of nuclear division in eukaryotic cells. Mitosis produces two genetically identical diploid cells for growth and replacement, w...This page details the differences between mitosis and meiosis, two types of nuclear division in eukaryotic cells. Mitosis produces two genetically identical diploid cells for growth and replacement, while meiosis results in four genetically diverse haploid cells essential for sexual reproduction.
- https://bio.libretexts.org/Bookshelves/Introductory_and_General_Biology/Biology_(Kimball)/07%3A_Cell_Division/7.06%3A_Sex_ChromosomesThis page explores human sexual chromosomes, focusing on the roles of X and Y chromosomes in sex determination, the significance of the SRY gene, and examples of genetic conditions like hemophilia and...This page explores human sexual chromosomes, focusing on the roles of X and Y chromosomes in sex determination, the significance of the SRY gene, and examples of genetic conditions like hemophilia and Turner syndrome. It also discusses sex determination in other species, including Klinefelter's syndrome, the role of the X chromosome in fruit flies, and ZZ/ZW systems in birds.
- https://bio.libretexts.org/Courses/City_College_of_San_Francisco/Introduction_to_Genetics/03%3A_Meiosis_-_Sexual_Reproduction/3.03%3A_Meiosis_IIThis page explains meiosis II, which follows meiosis I and divides two haploid cells without DNA replication. It includes prophase II, prometaphase II, metaphase II, anaphase II, telophase II, and cyt...This page explains meiosis II, which follows meiosis I and divides two haploid cells without DNA replication. It includes prophase II, prometaphase II, metaphase II, anaphase II, telophase II, and cytokinesis. The process results in the separation of sister chromatids, producing four genetically unique haploid cells due to random assortment and recombination during crossover.
- https://bio.libretexts.org/Bookshelves/Introductory_and_General_Biology/Biology_(Kimball)/05%3A_DNA/5.06%3A_The_Meselson_-_Stahl_ExperimentThis page explains semiconservative DNA replication, where the two strands of DNA separate to serve as templates for new strands. Proposed by Watson and Crick and validated by the Meselson-Stahl exper...This page explains semiconservative DNA replication, where the two strands of DNA separate to serve as templates for new strands. Proposed by Watson and Crick and validated by the Meselson-Stahl experiment, this process ensures each daughter DNA molecule consists of one old and one new strand, resulting in an "immortal strand" passed through generations. This mechanism is observed in both bacteria such as E. coli and eukaryotic organisms during chromosome replication.
- https://bio.libretexts.org/Bookshelves/Introductory_and_General_Biology/Biology_(Kimball)/14%3A_Embryonic_Development_and_its_Regulation/14.09%3A_Germline_vs._SomaThis page discusses the difference between mutations in somatic cells and germline cells. Somatic mutations, occurring in non-reproductive cells like liver cells, are not inherited and die with the in...This page discusses the difference between mutations in somatic cells and germline cells. Somatic mutations, occurring in non-reproductive cells like liver cells, are not inherited and die with the individual. In contrast, germline mutations in sperm and eggs can be passed to future generations, making them significant in genetic inheritance. Understanding this distinction is crucial for comprehending how genetic information is transmitted across generations.
- https://bio.libretexts.org/Courses/City_College_of_San_Francisco/Introduction_to_Genetics/09%3A_Mutation_and_Variation/9.08%3A_Linkage_and_Mapping/9.8.01%3A__LinkageMendel’s Second Law does not apply to every pair of genes that could be studied. In fact, we now know that alleles of loci that are located close together on the same chromosome tend to be inherited ...Mendel’s Second Law does not apply to every pair of genes that could be studied. In fact, we now know that alleles of loci that are located close together on the same chromosome tend to be inherited together. This phenomenon is called linkage, and is a major exception to Mendel’s Second Law of Independent Assortment. Researchers use linkage to determine the location of genes along chromosomes in a process called genetic mapping and is important to natural processes of heredity and evolution.
- https://bio.libretexts.org/Bookshelves/Botany/The_Science_of_Plants_-_Understanding_Plants_and_How_They_Grow_(Michaels_et_al.)/13%3A_Sexual_Reproduction/13.01%3A_DNAWhen a cell is not dividing, parts of the chromosome relax, unfold, and uncoil so that the DNA base pairs in specific parts of the chromosome that provide the code for specific cellular functions can ...When a cell is not dividing, parts of the chromosome relax, unfold, and uncoil so that the DNA base pairs in specific parts of the chromosome that provide the code for specific cellular functions can open up, be copied, and the code can be translated into proteins that do the cell’s metabolic business — a phase called “interphase“).
- https://bio.libretexts.org/Bookshelves/Introductory_and_General_Biology/Biology_(Kimball)/13%3A_Aging/13.02%3A_TelomeresThis page discusses eukaryotic chromosomes, highlighting the role of telomeres in cellular aging and cancer proliferation, as well as potential gene therapy applications. It also covers Dolly the shee...This page discusses eukaryotic chromosomes, highlighting the role of telomeres in cellular aging and cancer proliferation, as well as potential gene therapy applications. It also covers Dolly the sheep, the first cloned mammal, whose early health issues sparked debate about the long-term effects of cloning and telomere length.
- https://bio.libretexts.org/Bookshelves/Introductory_and_General_Biology/Biology_(Kimball)/07%3A_Cell_Division/7.05%3A_EndoreplicationThis page discusses endoreplication, a process of DNA replication during the S phase without mitosis or cytokinesis, found in some animal and plant cells. Variants include replication with mitosis but...This page discusses endoreplication, a process of DNA replication during the S phase without mitosis or cytokinesis, found in some animal and plant cells. Variants include replication with mitosis but no cytokinesis and multiple rounds of replication without new nuclei. This can cause polyploidy or polyteny, the latter evident in Drosophila larva, where polytene chromosomes allow for gene amplification and increased expression.
