Sapling Learning Questions from Lecture 1 and 2 – Flashcards
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What are the structures in a cell that group genes together, are composed of chromatin (DNA and protein), and become visible under a light microscope during mitosis?
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Chromosomes
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Term Definitions
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Gene: a chromosomal region that codes for a functional transcript and a functional unit of heredity Allele: an alternative forms of a particular gene Chromosome: threadlike DNA molecules that are visible during mitosis and large genetic element that carries genes essential to cellular function.
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More Term Definitions
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Gene: determines a particular characteristic of an organism, codes for a specific protein or RNA and acts as the basic unit of heredity. Chromosome: is a contiguous piece of DNA, is a unit of DNA carrying genetic info encoded in genes, functions to package, organize and regulate access to DNA, is the largest molecule in the cell and is a linear or circular molecule. Genome: may include plasmids, describes the collection of all the replicable genetic material of a cell or organism, each organism has one, and encodes all the heritable traits of an organism.
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How did Mendel use self-pollination and cross-pollination techniques in his experiments with flower color to observe the basic patterns of inheritance?
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By cross-pollinating a parental generation of plants with same colored flowers and allowing the F1 generation to self-pollinate. Mendel observed the basic patterns of inheritance in the F2 generation.
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How is a true breeding yellow-seeded pea plant different from a hybrid yellow seeded pea plant?
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They have the same phenotype but different genotypes.
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What are the functions of mitotic cell division?
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- Asexual reproduction - Replacement of cells - Growth of multicellular organisms
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Cell division by mitosis is a mechanism of asexual cell replication. Some single-cell organisms reproduce by cell division, and cell division enables multicellular organisms to grow and to repair damaged cells. Which of the following are products of cell division by mitosis?
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Two cells genetically identical to the original cell.
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Meiosis and mitosis are both forms of cell division. However, the outcomes of these processes differ. Consider a diploid organism with two sexes. Select the reasons why meiosis typically produces genetic variation, whereas mitosis does not.
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- Independent assortment results in alleles for a gene being passed separately to gametes during meiosis. - Genetic material is exchanged between homologous chromosomes in meiosis during crossing over. - Meiosis produces four genetically different haploid cells.
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Consider two cells, where one cell is haploid and the other is diploid. Which of the following differences between the two cells is observed during prophase of mitosis?
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In the haploid cell, only one pair of sister chromatids are present, whereas in the diploid cell, two pairs of sister chromatids are present.
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What happens during anaphase I of meiosis?
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Homologous chromosomes separate but sister chromatids remain joined at their centromeres.
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What happens during prophase I of meiosis?
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Homologous chromosomes form and crossing over occurs between them.
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What happens during telophase II of meiosis?
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The nuclear membrane begins to form around haploid sets of chromosomes.
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Steps between Prophase I and Metaphase I
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1. Chromosomes begin to condense 2. The synaptonemal complex aligns homologs into tetrads. 3. Crossing over occurs, during which nonsister chromatids exchange DNA. 4. Homologs are connected by chiasmata as the synaptonemal complex begins to separate. 5. Chromosomes condense further as chiasmata become more visible during separation.
