TOPIC 3 : CELL DIVISION

Cell division practice: Mitosis, meiosis, cell cycle, and more!

The significance of mitosis in human :I Asexual reproductionII Repair of damaged tissueIII GrowthIV Gamete production I only I and II I, II and III II, III and IV In eukaryotic cell division, the process of cytoplasmic division is called cytokinesis cytomeiosis cytoplasmosis cytomitosis In animals, somatic cell are produced by mitosis and _ are produced by meiosis. gametes clones zygotes spores All of the following are functions of meiosis in plants EXCEPT Production of spores Reduction of chromosome number by half Production of identical daughter cells Independent assortment of chromosomes In mitosis, the number of chromosome sets in daughter cells will be half the number in the parent cell twice the number in the parent cell the same as in parent cell one forth the number in the parent cell "The cell's DNA replicates". This event occurs in cell cycle during M phase G1 phase S phase G2 phase Which of the following statement is FALSE about the cell cycle? Development of spindle fibers occur in G2 The cell spends the most amount of time in G2 phase G1 is the longest time taken in the cell cycle of most cells G1 is the time when the cell increases in size The events in the cell cycle that are in the CORRECT order is Chromosome align at equator, kinetochores attach at spindle fibers, cytokinesis, new nuclear membrane form Interphase, centrioles move to opposite poles, anaphase, chromosome decondense Interphase, sister chromatids completely separated, kinetochores attach to the spindle fibers, cytokinesis Chromosomes condense, DNA replication occurs, nuclear membrane breaks down, telophase Interphase is the part of the cell cycle when a cell ceases to function a germ cell forms its spindle apparatus a cell grows and replicates its DNA mitosis proceeds Which of the following is NOT a stage of mitosis? prophase interphase metaphase anaphase Synthesis of RNA and proteins take place in G1 phase S phase karyokinesis cytokinesis Which phase comes between G1 and G2 phases? resting phase M S prophase Which of the following is the behaviour of the chromosome during mitosis? Early mitotic spindle formed from the centrosomes Nuclear envelope disappears Sister chromatids separate from each other to the poles of the cells Two cells formed by formation of cleavage furrow How does mitosis in plant cells differ from that in animal cells? Animal cells form cell plate Animal cells lack cytokinesis Plant cells form cell plate Plant cells lack spindle fibers Which of the following statements is FALSE about mitosis? Single nucleus gives rise to two Produce identical daughter nuclei The centromeres divide at the onset of anaphase Homologous chromosomes align at the metaphase plate The phase of cell division in which the nuclear envelope and nucleolus are disappearing is called metaphase telophase anaphase prophase All of the following occur during prophase of mitosis in animal cells EXCEPT The centrioles move toward opposite poles Chromosomes are duplicated The nucleolus can no longer be seen The spindle is organized Which of the following statements is NOT true? Mitosis produces new nuclei with exactly the same chromosomal number as the parent nucleus Mitosis produces genetically non identical daughter cells as the parent cell Mitosis and cytokinesis are required for asexual reproduction The mitotic spindles in eukaryotic cells are composed of microtubules During prophase, a homologous pair of chromosome consist of 4 chromosomes; 4 chromatids 2 chromosomes; 2 chromatids 2 chromosomes; 4 chromatids 1 chromosome; 2 chromatids After mitosis, the chromosome number of a daughter cell is _ the parent's cell the same as one-half rearranged compared to doubled compared to Taxol is an anticancer drug extracted from the Pacific yaw tree. In animal cells, taxol distrupts microtubules formation by binding to microtubules and accelerating their assembly from the protein precursor, tubulin. Surprisingly, this stops mitosis. Specifically, taxol must affect the fibers of the mitotic spindle formation of centrioles chromatid assembly anaphase In animal cells, cytokinesis takes place by cytoplasmic contraction furrowing process membrane fusion formation of cell plate Cytokinesis usually, but not always, follows mitosis. If a cell completed mitosis but not cytokinesis, the result would be a cell with a single large nucleus high concentrations of actin and myosin two nuclei two nuclei but with half the amount of DNA How do the daughter cells at the end of mitosis and cytokinesis compare with their parent cell when it was in G1 of the cell cycle? The daughter cells have half the amount of cytoplasm and half number of DNA The daughter cells have same amount of cytoplasm and half number of DNA The daughter cells have same number of chromosomes and half number of DNA The daughter cells have same number of chromosomes and same number of DNA Where do the microtubules of the spindle originate during mitosis in both plant and animal cells? centromere centrosome centriole kinetochore When pairs of homologous chromosomes separate during anaphase I The maternal chromosomes all move to one daughter cell, and the paternal chromosomes all move to the other daughter cell The sister chromatids remain linked to one another The genetic composition remain the same Centromere splits Immediately after telophase I of meiosis, the chromosomal makeup of each daughter cell is diploid, and the chromosomes are composed of a single chromatid diploid, and the chromosomes are composed of the two chromatids haploid, and the chromosomes are composed of a single chromatid haploid, and the chromosomes are composed of two chromatids. All of the following are functions of meiosis in plants EXCEPT Production of spores Reduction of chromosome number by half Production of identical daughter cells Independent assortment of chromosomes How do the cells at the completion of meiosis differ from the parent cell during G2 phase? They have twice the amount of cytoplasm and half the number of DNA They have half the number of chromosomes and half the number of DNA They have the same number of chromosomes and half the number of DNA They have half the number of chromosomes and one-fourth the number of DNA Which of the following statements about crossing over is INCORRECT? Crossing over combines sections of the maternal and paternal chromosomes Crossing over plays a role in both sexual and asexual reproduction There are on average one to three crossover events per chromosome Crossing over increases the extent of genetic variation beyond what is possible through independent assortment alone When comparing prophase I of meiosis with prophase of mitosis, which of the following occurs only in meiosis? The chromosomes condense Tetrads form The nuclear envelope disassembles A spindle forms Which of these statements is FALSE? In humans, each of the 22 maternal autosomes has a homologous paternal chromosome In humans, the 23rd pair, the sex chromosomes, determines whether the person is female or male Single, haploid set of chromosomes in ovum and sperm unite during fertilization, forming a diploid, single celled zygote At sexual maturity, ovaries and testes produce diploid gametes by meiosis. Figure above shows an animal cell at the stage of anaphase II. What is the number of chromosomes that are found in the animal's diploid cell? 3 6 12 24 Which diagram represents prophase I of meiosis? I II III IV During meiosis, the formation of four nuclei occurs at Prophase I Anaphase II Metaphase I Telophase II The following of cell division, the chromosome composed of two chromatids The G1 phase of a mitotic cell cycle Late anaphase of mitosis Late anaphase II of meiosis Telophase I of meiosis Which the following is TRUE about meiosis?I Meiosis occurs to form gametesII The genetic constitution of the daughter cells is the sameIII The number of chromosomes is reduced by halfIV Two daughter cells are formed at the end of the process I, II and III I and III II and IV IV only Which of the following happens at the completion of meiosis I? Homologous chromosomes are separated The chromosome number is conserved Sister chromatids are separated Four daughter cells are formed Homologous chromosomes separate and end up at the opposite spindle poles during _. prophase I prophase II anaphase I anaphase II Sister chromatids separate and end up opposite spindle poles during _. prophase I prophase II anaphase I anaphase II Meiosis is a division mechanism that produces _. two cells two nuclei eight cells four nuclei At what phase of meiosis are there two cells, each with sister chromatids aligned at the spindle equator? metaphase II metaphase I anaphase I anaphase II Complete the table below with a tick ( if the statement is TRUE or a cross (X) if it is FALSE. Centromere split Spindle fibers form Homologous chromosomes pair up DNA replication occurs at the start of the division Crossing over occurs Mitosis / / X / X Meiosis I X / / / / Meiosis II / / X X X Read through the following passage about mitosis and then write a list of the most suitable words to fill the gaps. During mitosis a cell divides to form two daughter cells with identical genetic composition. Replication of DNA occurs during interphase . The first stage of mitosis is called prophase in which the chromosomes condense and can be seen to consist of two chromatids joined together by the centromere . Then the nuclear membrane disappears and spindle fibres forms in the cell. The chromosomes lined up at the metaphase plate of the cell at the stage called metaphase . Daughter chromosomes separate and pulled to opposite poles. Nuclear division is followed by cytokinesis .