Answers to Review for Unit Test - 3 - Cellular Reproduction - Mitosis, Meiosis, Karyotypes and Non-disjunction Disorders

Sep 30, 2026

Answers to a review worksheet for Unit Test #3 on cellular reproduction. The content guides students through key biology concepts including definitions of cell cycle terms, structures such as chromatin, chromosomes, chromatids, centromeres, and ploidy states, plus processes of mitosis, meiosis, cytokinesis in plant and animal cells, and fertilization-linked outcomes. It also explains distinctions between related terms and addresses non-disjunction disorders and related chromosome-number syndromes with an emphasis on clear conceptual understanding for assessment.

LanguageEnglish

CategoryExam

FormatPDF

Pages8

Reading Time20 min

AccessFree to download

Cellular Reproduction: Mitosis, Meiosis, Karyotypes and Non-disjunction Disorders

Review resources and quiz

Definitions of key terms

Differences between core concepts

Cytokinesis in plant and animal cells

Mitosis vs cytokinesis

Mitosis vs meiosis

Answers to Review for Unit Test \#3: Cellular Reproduction: Mitosis, Meiosis, Karyotypes and Non-disjunction Disorders It may help you to review mitosis, meiosis and non-disjunction by watching the following narrated animations. They are excellent. There is a summary of the important points and a quick quiz at the end: Mitosis in animal cells (do not worry about kinetochores) [http://www.sumanasinc.com/webcontent/animations/content/mitosis.html](http://www.sumanasinc.com/webcontent/animations/content/mitosis.html) Meiosis in animal cells (do not worry about interkinesis) [http://www.sumanasinc.com/webcontent/animations/content/meiosis.html](http://www.sumanasinc.com/webcontent/animations/content/meiosis.html) [Non-disjunction disorders](Non-disjunction disorders) ([do not worry about aneuploidy or polyploidy](do not worry about aneuploidy or polyploidy)) [http://www.sumanasinc.com/webcontent/animations/content/mistakesmeiosis/mistakesmeiosis.html](http://www.sumanasinc.com/webcontent/animations/content/mistakesmeiosis/mistakesmeiosis.html) [1](1). Know and understand the definitions and meanings of the following terms. prokaryotic cell Cell cycle crossing-over eukaryotic cell interphase chiasmata chromatin mitosis gametes histones meiosis fertilization DNA replication cytokinesis zygote mutation cleavage furrow spermatogenesis point mutation cell plate oogenesis frameshift mutation Interphase, Gap 1 ova (ovum) gene Interphase, Synthesis sperm oncogene (from homework) Interphase, Gap 2 pollen unduplicated chromosome prophase, prophase I and prophase II karyotype duplicated chromosome metaphase, metaphase I and metaphase II autosome chromatid anaphase, anaphase I and anaphase II sex chromosome sister chromatids telophase, telophase I and telophase II non-disjunction centromere homologous chromosomes syndrome haploid synapsis monosomy diploid tetrad trisomy 2. Clearly explain the difference between the following: a) chromosomes and chromatin • Chromatin is the name of the “form” of DNA during interphase, when the cell is between divisions. Chromatin is always found in the nucleus. It is only slightly coiled, with the DNA wrapped around histone proteins. Chromatin allows the DNA to be unwound and unzipped so it can be copied to make mRNA for protein synthesis or for DNA replication during the Synthesis phase of interphase • Chromosomes are a highly condensed form of DNA which is found only during mitosis or meiosis. The DNA in chromosomes is ‘super-coiled’ to prevent the DNA from breaking when it is being lined up during metaphase and pulled through the cytoplasm toward the poles during anaphase b) the cell cycle and mitosis • The cell cycle is the entire lifecycle of a cell. It is sub-divided into interphase and division. Division is further divided into mitosis and cytokinesis. Cells spend their entire life going through the cell cycle, but only a very short part of their life is spent in mitosis. Some cells, such as nerve, heart and muscle cells, almost never go through mitosis. • Mitosis is just one part of the cell cycle; it is just the division of the nuclear material and includes prophase, metaphase, anaphase and telophase. c) cytokinesis in plant and animal cells • Cytokinesis refers to the division of the cytoplasm between two daughter cells. It is a part of the cell cycle, but is technically not part of mitosis. • In an animal cell (which does not have a cell wall), cytokinesis takes place when the cell membrane “pinches in” at the cleavage furrow and the cytoplasm is divided into two cells • In a plant cell (which does have a cell wall), cytokinesis takes place when a cell plate forms along the cell’s equator after the chromosomes have been pulled to opposite poles. The cell plate grows from the middle out (← →), across the centre of the cell, dividing the cytoplasm between both daughter cells. d) chromatin and chromatid Animal Cell Plant Ce

FAQs

What is the difference between chromatin and chromosomes?

Chromatin is the DNA form in interphase, found in the nucleus and wrapped around histones so DNA can be unwound for copying. Chromosomes are a highly condensed, super-coiled DNA form seen during mitosis or meiosis to prevent breakage while alignment and pulling occur.

How do mitosis and meiosis differ in purpose and cell outcomes?

Mitosis prepares for asexual reproduction, involves one division, and produces two essentially identical diploid daughter cells for maintenance, growth, and repair. Meiosis prepares for sexual reproduction, involves two successive divisions in germ cells, and produces four unique haploid gametes (eggs and sperm).

How does cytokinesis differ between animal and plant cells?

In animal cells, cytokinesis occurs when the cell membrane pinches in at the cleavage furrow to divide the cytoplasm. In plant cells, cytokinesis occurs by formation of a cell plate along the equator, growing from the middle outward to separate the cytoplasm between daughter cells.

Sep 30, 2026

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