BIOL 1P91 Exam Review Questions With Answers | Updated

BIOL 1P91 Exam Review Questions With Answers | Updated Chromatids - ANSWER One half of a replicated chromosome. Each chromatid contains one double helix of DNA. binary fission - ANSWER A form of asexual reproduction in single-celled organisms by which one cell divides into two cells of the same size, Prokaryotic cell division—splitting or dividing into two parts Nucleoid - ANSWER The central region of a prokaryotic cell with no boundary membrane separating it from the cytoplasm, where DNA replication and RNA transcription occur. origin of replication (ori) - ANSWER DNA sequence at which helicase unwinds the DNA double helix and DNA polymerase binds to initiate DNA replication. A specific region at which replication of a bacterial chromosome commences. Mitosis - ANSWER Nuclear division that produces daughter nuclei that are exact genetic copies of the parental nucleus. Chromosomes - ANSWER threadlike structures made of DNA molecules that contain the genes The nuclear unit of genetic information, consisting of a DNA molecule and associated proteins diploid or 2n - ANSWER An organism or cell with two copies of each type of chromosome in its nucleus. haploid or n - ANSWER An organism or cell with only one copy of each type of chromosome in its nuclei. ploidy - ANSWER The number of chromosome sets of a cell or species. sister chromatids - ANSWER One of two exact copies of a chromosome duplicated during replication. chromosome segregation - ANSWER The equal distribution of daughter chromosomes to each of the two cells that result from cell division. Interphase - ANSWER The first stage of the mitotic cell cycle, during which the cell grows and replicates its DNA before undergoing mitosis and cytokinesis. G1 phase of interphase - ANSWER the cell carries out its function and, in some cases, grows. S phase of interphase - ANSWER DNA replication and chromosome duplication occur G2 phase of interphase - ANSWER a brief gap in the cell cycle during which cell growth continues and the cell prepares for mitosis (the fourth phase of the cell cycle; also called M phase) and cytokinesis. G 0 phase of interphase - ANSWER Cells that are not destined to divide immediately enter a shunt from G1 called the G0 phase. In some cases, a cell in G0 may start dividing again by re-entering G1. Prophase - ANSWER The beginning phase of mitosis during which the duplicated chromosomes within the nucleus condense from a greatly extended state into compact, rodlike structures. Nucleosome - ANSWER The basic structural unit of chromatin in eukaryotes, consisting of DNA wrapped around a histone core. Linker - ANSWER A short segment of DNA extending between one nucleosome and the next in a eukaryotic chromosome mitotic spindle - ANSWER The complex of microtubules that orchestrate the separation of chromosomes during mitosis. Spindle poles - ANSWER One of the pair of centrosomes in a cell undergoing mitosis from which bundles of microtubules radiate to form the part of the spindle from that pole. Prometaphase - ANSWER A transition period between prophase and metaphase during which the microtubules of the mitotic spindle attach to the kinetochores and the chromosomes shuffle until they align in the centre of the cell. kinetochore - ANSWER A specialized structure consisting of proteins attached to a centromere that mediates the attachment and movement of chromosomes along the mitotic spindle. Metaphase - ANSWER The phase of mitosis during which the spindle reaches its final form and the spindle microtubules move the chromosomes into alignment at the spindle mi