Genetics: Mitosis and Meiosis Overview
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Questions and Answers

Which phase of meiosis is primarily responsible for recombination?

  • Anaphase II
  • Prophase I (correct)
  • Telophase II
  • Metaphase I

During meosis II, haploid cells remain haploid after division.

True (A)

What does recombination create during meiosis?

New combinations of alleles

________ cells are produced after meiosis.

<p>Haploid</p> Signup and view all the answers

Match the following meiosis phases with their key events:

<p>Prophase I = Recombination Metaphase I = Alignment of homologous chromosomes Anaphase I = Separation of homologous chromosomes Telophase II = Formation of daughter cells</p> Signup and view all the answers

What is the likelihood of gene A and B being inherited together?

<p>93% (C)</p> Signup and view all the answers

Chiasma refers to the point where crossover events occur between non-homologous chromosomes.

<p>False (B)</p> Signup and view all the answers

What is the term used when there is an abnormal number of chromosomes in gametes?

<p>Aneuploidy</p> Signup and view all the answers

The chance that gene A and C alleles are inherited together is _____%.

<p>53</p> Signup and view all the answers

Match the following terms with their definitions:

<p>Crossover = Exchange of genetic material between homologous chromosomes Independent Assortment = Random separation of alleles during gamete formation Non-disjunction = Failure of chromosomes to separate properly during meiosis Chiasma = Point where chromatids exchange genetic material</p> Signup and view all the answers

Which meiotic division is least likely to result in aneuploidy?

<p>Meiosis 2 (C)</p> Signup and view all the answers

If genes are located on different chromosomes, they will always be inherited together.

<p>False (B)</p> Signup and view all the answers

What does the term 'haploid' refer to?

<p>A cell with one set of chromosomes (n)</p> Signup and view all the answers

What is the primary outcome of meiosis compared to mitosis?

<p>Four non-identical cells are produced. (B)</p> Signup and view all the answers

Independent assortment ensures that alleles segregate randomly during the formation of gametes.

<p>True (A)</p> Signup and view all the answers

What is aneuploidy?

<p>An abnormal number of chromosomes in a cell.</p> Signup and view all the answers

In meiosis, a reduction in the chromosome number occurs during ________.

<p>meiosis I</p> Signup and view all the answers

Match each condition with its description:

<p>Trisomy 21 = Caused by an extra chromosome 21 Double Y = Condition affecting males with an extra Y chromosome Nondisjunction = Failure of chromosomes to separate properly Recombination = Exchange of genetic material between homologous chromosomes</p> Signup and view all the answers

Which of the following occurs during homologous recombination?

<p>Genetic material is exchanged between homologous chromosomes. (D)</p> Signup and view all the answers

All genetic mutations affect reproductive organs.

<p>False (B)</p> Signup and view all the answers

What is the outcome of random fertilization?

<p>Unique zygotes are formed.</p> Signup and view all the answers

After meiosis, the resulting gametes have a __________ set of chromosomes.

<p>haploid</p> Signup and view all the answers

What is the total number of chromosomes in a diploid cell denoted as?

<p>2n (C)</p> Signup and view all the answers

What is the result of non-disjunction during meiosis 2?

<p>Two normal gametes (D)</p> Signup and view all the answers

The likelihood of having a child with Down Syndrome decreases as a mother ages.

<p>False (B)</p> Signup and view all the answers

What chromosomal disorder is associated with extra digits and serious brain problems?

<p>Trisomy 13 (Patau Syndrome)</p> Signup and view all the answers

During metaphase, chromosomes line up and a __________ is taken.

<p>picture</p> Signup and view all the answers

What is the fate of most infants with trisomy 18?

<p>They die within the first month (B)</p> Signup and view all the answers

Match the chromosomal disorders with their main characteristics:

<p>Down Syndrome = Trisomy 21 Patau Syndrome = Trisomy 13 Edwards Syndrome = Trisomy 18 Klinefelter Syndrome = Extra X chromosome in males</p> Signup and view all the answers

Mitosis is responsible for the production of gametes in all organisms.

<p>False (B)</p> Signup and view all the answers

What is the chromosome configuration of a 'Super Male'?

<p>Double-Y Chromosome</p> Signup and view all the answers

Flashcards

Haploid (n)

A cell containing one set of chromosomes.

Diploid (2n)

A cell containing two sets of chromosomes.

Meiosis

Cell division that results in four haploid daughter cells.

Recombination

The exchange of genetic material between homologous chromosomes during meiosis.

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Linked Genes

Genes located close together on the same chromosome that tend to be inherited together.

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Crossing Over

The exchange of genetic material between homologous chromosomes during meiosis.

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Chiasma

The point where crossing over occurs between homologous chromosomes.

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Independent Assortment

The random alignment of homologous chromosomes during meiosis, leading to different combinations of alleles in gametes.

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Aneuploidy

A chromosomal abnormality where gametes have an abnormal number of chromosomes.

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Non-disjunction

Failure of chromosomes to separate properly during meiosis, leading to aneuploidy.

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Gamete

A reproductive cell (sperm or egg) containing half the number of chromosomes of a normal body cell.

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Homologous recombination

Exchange of genetic material between homologous chromosomes during meiosis, creating new combinations of alleles.

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Random fertilization

The random combination of gametes during sexual reproduction, creating unique zygotes.

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Non-disjunction in Meiosis II

A mistake during the second meiotic division where homologous chromosomes do not separate properly. Results in some gametes having an extra chromosome and others missing a chromosome.

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Down Syndrome

A genetic disorder caused by an extra copy of chromosome 21. Characterized by intellectual and developmental delays.

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Trisomy 13 (Patau Syndrome)

A chromosomal disorder with significant birth defects, often leading to death in infancy.

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Trisomy 18 (Edwards Syndrome)

A chromosomal disorder with severe physical and intellectual disabilities, often resulting in death before or shortly after birth.

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Supermale

A genetic condition characterized by an extra Y chromosome (XYY).

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Study Notes

Genetic Variety and Diversity

  • Homologous recombination shuffles alleles along chromosome pairs
  • Independent assortment: alleles align randomly during meiosis
  • Random fertilization: specific sperm fertilizes egg randomly producing unique zygotes

Mitosis

  • Single cell division creating two identical daughter cells
  • Two identical sets of chromosomes
  • Occurs in somatic (body) cells

Meiosis

  • Two-part cell division producing four non-identical daughter cells
  • Each cell contains half the original chromosomes
  • Occurs in sex organs (ovaries and testes), creating gametes (sperm and egg cells)

Meiosis I (Reductional)

  • Homologous chromosomes separate
  • Recombination occurs, creating new gene combinations

Meiosis II (Equational)

  • Sister chromatids separate similarly to mitosis
  • Creates four genetically unique haploid gametes

Recombination

  • Reshuffling of alleles from homologous chromosomes
  • Creates new allele combinations within gametes

Linked Genes

  • Genes located near each other on a chromosome
  • More likely to be inherited together due to low chance of crossing-over

Aneuploidy

  • Abnormal number of chromosomes due to errors in meiosis
  • Causes different chromosome copies during gamete creation
  • Nondisjunction: Chromosomes fail to separate during meiosis, resulting in gametes with extra or missing chromosomes

Sex Chromosome Combinations in Zygotes

  • Errors in meiosis can lead to abnormal sex chromosome combinations
  • Examples: Turner syndrome (XO), Klinefelter syndrome (XXY), Triple X syndrome (XXX)

Super Male

  • 47, XYY karyotype (one extra Y chromosome)

Animal Life Cycle

  • Zygote (2n) undergoes mitosis to develop into an organism
  • Organisms produce haploid gametes through meiosis
  • Fertilization produces a zygote, completing the cycle

Plant and Fungi Life Cycle

  • Sporophyte (2n) undergoes meiosis to produce spores (n)
  • Spores germinate into gametophytes
  • Gametophytes produce gametes (n) through mitosis
  • Fertilization produces a zygote (2n), the starting point

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L5 - Meiosis and Recombination PDF

Description

Explore the fundamental processes of mitosis and meiosis, including genetic variety through homologous recombination and independent assortment. Understand how these processes contribute to genetic diversity and the formation of gametes. This quiz covers essential concepts essential for biology students.

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