IB Biology I -Guide Questions: Mitosis and Meiosis Ch 12-13
For best effect
- do NOT complete this as a simple worksheet! But, yes you do need to turn in the “final product” Q/A
-Compile and review all your resources that relate to the following questions (command terms
handout, textbook, lecture notes, reading notes, other notes/handout’s,…)
Reminder:
-“Read it, write it, synthesize it, say it, evaluate it” and Repeat
-“Read it”: reread/review the materials
Test will
-“Write it”: compile unedited notes that bring all information related to the question together (scratch paper, index
include
cards, post-its, whatever medium and format floats your boat )
-“Synthesize it”: Bring the essential information together to provide a concise (max 200words…though some answers
Review
will be much shorter), well argued, and supported answer to the question.
Questions!
-“Say it”: read the question and the answer aloud. Does the answer truly answer the question? When relevant: Does
the logic and evidence hold up? You would be surprised the number of times a student mixes up their “cause” and
“effect” when writing a formal answer. Or, students leave out the evidence and just make unsubstantiated conclusions!
-“Evaluate it”: Does it use precise scientific language? Don’t use pronouns, when specific nouns ensure clarity! Is there enough detail? Is there
too much detail? If it is a written answer, would a labeled diagram help? If it is a drawn answer, is it fully labeled and fully annotated?
-Repeat until you are satisfied, and record a clear, concise, answer!
These are directly from the IB standards; add illustrations, diagrams, examples,
additional details to make the most of your studying for the test
Cell division
2.5.1 Outline the stages in the cell cycle, including interphase (G1, S, G2), mitosis and cytokinesis.
2.5.2 State that tumours (cancers) are the result of uncontrolled cell division and that these can occur in any organ or tissue.
2.5.3 State that interphase is an active period in the life of a cell when many metabolic reactions occur, including protein synthesis, DNA
replication and an increase in the number of mitochondria and/or chloroplasts.
2.5.4 Describe the events that occur in the four phases of mitosis (prophase, metaphase, anaphase and telophase).
2.5.5 Explain how mitosis produces two genetically identical nuclei.
2.5.6 State that growth, embryonic development, tissue repair and asexual reproduction involve mitosis.
Meiosis
4.2.1 State that meiosis is a reduction division of a diploid nucleus to form haploid nuclei.
4.2.2 Define homologous chromosomes.
4.2.3 Outline the process of meiosis, including pairing of homologous chromosomes and crossing over, followed by two divisions, which
results in four haploid cells.
4.2.4 (not major focus…cover in more depth during ch15!)Explain that non-disjunction can lead to changes in chromosome number,
illustrated by reference to Down syndrome (trisomy 21).
4.2.5 State that, in karyotyping, chromosomes are arranged in pairs according to their size and structure.
4.2.6 (not major focus…cover in more depth during ch15!)State that karyotyping is performed using cells collected by chorionic villus
sampling or amniocentesis, for pre-natal diagnosis of chromosome abnormalities. (basics only…cover in more depth during ch15!)
4.2.7 (not major focus…cover in more depth during ch15!)Analyse a human karyotype to determine gender and whether non- disjunction has
occurred.
Meiosis
10.1.1 Describe the behaviour of the chromosomes in the phases of meiosis.
10.1.2 Outline the formation of chiasmata in the process of crossing over.
10.1.3 Explain how meiosis results in an effectively infinite genetic variety in gametes through crossing over in prophase I and random
orientation in metaphase I.
10.1.4 (Not
Yet! Ch14) State Mendel?s law of independent assortment.
Allele pairs seperate independently during gamete formation which means that the transmission of traits to offspring are
independent to one another.
10.1.5 (Not Yet! Ch14) Explain the relationship between Mendel?s law of independent assortment and meiosis.
During metaphase I of meiosis the homologous pairs of chromosomes align along the equator. The orientation of the chromosomes is random.
This means that when the pairs of homologous chromosomes move to opposite poles during anaphase I, either chromosome can end up at
either pole. This depends on which way the pair is facing (occurs randomly). Also, which ever way the pair is facing does not affect which way
the other homologous chromosome pairs are facing. This is known as idenpendent orientation and forms the basis of Mendel's law of
independent assortment. Unlinked genes are found on different chromosomes so when the homologous chromosome pairs seperate it allows the
formation of daughter cells with random assortemnets of chromosomes and alleles.