Mitosis & Meiosis

Life Science - Middle School

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Meiosis I Before Meiosis Meiosis II Mitosis Cell Growth DNA Replication Cytokinesis Preparation for Mitosis Inte rp ha se The Cell Cycle The Cell Cycle Cells reproduce by a process called cell division. The cell cycle is the sequence of stages of growth and division that a cell undergoes. The three stages of the cell cycle include interphase, mitosis and cytokinesis. Meiosis During meiosis a parent cell divides into four sex cells, each with half the number of chromosomes. Sex cells of males are called sperm cells and sex cells of females are called egg cells. Prophase The chromatin condenses and spindle fibers form at each side of the cell. The nuclear membrane breaks apart. Anaphase The spindle fiber splits the centromere and the chromatids move to opposite sides of the cell. Telophase The chromosomes loosen on each side and the nuclear membrane begins to form around the chromatin (strands of DNA). Cytokinesis During this stage the cell membrane pinches in at the middle of the cell dividing it into two separate daughter cells. Each daughter cell gets half of the cell organelles and an identical set of chromosomes. 1 Before meiosis begins, chromosomes in the parent cell are copied. 2 Chromosome pairs line up in the middle of the cell. 3 The chromosome pairs split and pull apart to opposite ends of the cell. 4 Each of the two new cells formed has half the number of chromosomes. 5 Chromosome pairs line up in the middle of the cell. 6 The centromeres split and the single chromosomes move apart to opposite ends of the cell. 7 Four sex cells are produced, each with only one chromosome from each original pair. Interphase is the first stage of the cell cycle and the period before cell division. During this phase the cell matures, copies its DNA and prepares to divide. Meiosis Punnett Square female parent male parent A Punnett Square shows all the possible allele (gene) combinations in the offspring of two organisms. RR Rr Rr rr Rr Rr R r R r centriole chromatin daughter cells Metaphase The chromosomes line up along the center of the cell and the spindle fibers attach to each chromosome at the centromere. © Copyright NewPath Learning. All Rights Reserved. 94-4702 www.newpathlearning.com Mitosis & Meiosis chromatids chromatin centromere
\|xiBAHBDy01759sz\ Meiosis I Before Meiosis Meiosis II Mitosis Cell Growth DNA Replication Cytokinesis Preparation for Mitosis Int er ph as e The Cell Cycle The Cell Cycle Cells reproduce by a process called ____________________ . The __________________ is the sequence of stages of growth and division that a cell undergoes. The three stages of the cell cycle include ____________________ , ____________________ and ____________________ . Meiosis During __________________ a parent cell divides into four sex cells, each with half the number of chromosomes. Sex cells of males are called ____________________ and those of females are called ____________________ . Prophase The _____________ condenses and spindle fibers form at each side of the cell. The nuclear membrane breaks apart. Anaphase The spindle fiber splits the ________________ and the chromatids move to opposite sides of the cell. Telophase The chromosomes loosen on each side and the nuclear membrane begins to form around the chromatin (strands of DNA). Cytokinesis During this stage the cell membrane pinches in at the middle of the cell dividing it into two separate ____________________ . Each daughter cell gets half of the cell organelles and an identical set of ____________________ . 1 2 3 4 5 6 7 ____________________ is the first stage of the cell cycle and the period before cell division. During this phase the cell matures, copies its DNA and prepares to divide. Metaphase The _________________ line up along the center of the cell and the spindle fibers attach to each chromosome at the centromere. Key Vocabulary Terms anaphase interphase cell cycle meiosis cell division metaphase centromere mitosis chromatids prophase chromosomes Punnett square cytokinesis sex cells daughter cells sperm cells DNA spindle fibers egg cells telophase © Copyright NewPath Learning. All Rights Reserved. 94-4702 www.newpathlearning.com Mitosis & Meiosis