Chapter 10

During meiosis, the crossover occurs between (a) Sister chromatids of homologous chromosomes (b) Non-sister chromatids of homologous chromosomes (c) Sister chromatids of non-homologous chromosomes (d) Non-homologous chromatids of homologous chromosomes

Which of the following is not true for anaphase? (a) Golgi body and ER are reformed (b) Spindle poles move further apart (c) Chromosomes move to opposite poles (d) Centromeres split and chromatids separate

The longest phase of meiosis I is (a) Metaphase I (b) Prophase I (c) Anaphase I (d) Telophase I

Cyclin protein is required for cell cycle. Which other molecule is essential for the completion of cell cycle? (a) CCK (b) \(\mathrm{CKC}\) (c) CDK (d) CKD

Which is the correct statements from the following: I. Synapsis of homologous chromosomes takes place during prophase I of meiosis. II. Division of centromeres takes place during anaphase I of meiosis. III. Spindle fibres disappear completely in telophase of mitosis. IV. Nucleoli reappear at telophase I of meiosis. (a) I only (b) III only (c) I and II only (d) I, III and IV only

Assertion: The complex formed by a pair of synapsed homologous chromosome is called a bivalent or a tetrad. Reason: The first two stages of prophase I are relatively short lived when compared to the next stage that is pachytene.

Assertion: In oocytes of some vertcbrates, the diplotene can last for months or years. Reason: The final stage of meiotic prophase I is diakinesis.

Assertion: Liquid endosperm in coconut is multinucleated. Reason: Karyokinesis is not followed by cytokinesis.

Assertion: Mitosis maintains the genetic similarity of somatic cells. Reason: Chromosomes do not undergo crossing over.

Assertion: Chiasmata is formed during diplotene. Reason: Chiasmata are formed due to the deposition of nucleoproteins.

Assertion: Meiosis takes place in pollen mother cells. Reason: Each pollen mother cell produces 4 haploid pollen grains.

Assertion: Meiotic division results in the production of haploid cells. Reason: Synapsis occurs during zygotene of meiosis.

Assertion: Plant shows open growth. Reason: Plant contains meristmetic tissues.

Assertion: Prophase is characterised by formation of mitotic chromosome. Reason: Chromosomal material condenses in prophase stage.

Assertion: Morphology of chromosome is studied in metaphase stage. Reason: Condensation of chromosome is completed in this stage and can be easily visualised under microscope.

Assertion: Chromatid separation occurs in anaphase stage. Reason: Centromere splitting occurs in anaphase stage.

Assertion: In some social insect haploid cells divide by mitosis Reason: Growth of multicellular organism is due to mitosis

Assertion: Stage between two meiotic divisions (I \& II) is referred as interkinesis. Reason: Interkinesis is short lived phase.

Assertion: Meiotic division help in evolution process. Reason: Meiosis increases genetic variability in the population.

Assertion: The complex formed by a pair of synapsed homologous chromosome is called as tetrad. Reason: Each of the homologous chromosomes in meiotic prophase I consists a two closcly apposed sister chromatids.

Assertion: In oocytes, diplotene can last for months or years Reason: It is at this stage that chromosome decondense and engage in RNA synthesis

Assertion: Mitosis is called equational division. Reason: Mitosis is the division of parent cell into two identical daughter cells having the same amount of DNA as in parent cell.

Assertion: The interphase is considered as the most active stage of cell cycle. Reason: This phase is a period of intense synthesis and growth

Assertion: Disappearance of nuclear membrane is generally essential for karyokinesis. Reason: Forward movement of chromosomes is dependent on spindle apparatus, which organise is cytoplasm.

Assertion: Kinetochore is essential for cell division. Reason: Kinetochore serves as the sites of attachment of spindle fibres to the chromosome.

Assertion: Meiosis is also known as reduction division. Reason: Meiosis reduces the number of chromosome in daughter cells.

Assertion: Meiosis produces four genetically dissimilar cells. Reason: Crossing over or gene exchange takes place in meiosis.

Assertion: In mitotic metaphase, morphology of chromosomes can most easily study. Reason: Condensation of chromosomes is completed in this stage.

Assertion: Cell growth results into division. Reason: Cell growth leads to change in nucleocytoplasmic ratio.

Assertion: During pachytene crossing over takes place which is dependent on recombinase. Reason: Recombinase is the group of enzymes involved in crossing over and crossing over is an enzyme dependent process.

Assertion: Colchicine is a mitotic poison. Reason: Colchicine interferes in the arrangement of spindle fibres.