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Questions and Answers
What is the main purpose of meiosis?
What is the main purpose of meiosis?
Sister chromatids are formed during the cell cycle's interphase.
Sister chromatids are formed during the cell cycle's interphase.
False (B)
What term describes chromosomes that are similar in size and shape, with one coming from each parent?
What term describes chromosomes that are similar in size and shape, with one coming from each parent?
Homologous chromosomes
In humans, a gamete contains _____ chromosomes.
In humans, a gamete contains _____ chromosomes.
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Match the following terms with their definitions:
Match the following terms with their definitions:
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What is the result of nondisjunction during cell division?
What is the result of nondisjunction during cell division?
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Recessive traits are always expressed in the phenotype.
Recessive traits are always expressed in the phenotype.
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What is the process called when homologous chromosomes exchange genetic material during meiosis?
What is the process called when homologous chromosomes exchange genetic material during meiosis?
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What is the primary role of meiosis in organisms?
What is the primary role of meiosis in organisms?
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In a monohybrid cross, two parents contribute two different traits to their offspring.
In a monohybrid cross, two parents contribute two different traits to their offspring.
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What is the name of the cell formed from the fertilization of an egg and a sperm?
What is the name of the cell formed from the fertilization of an egg and a sperm?
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During __________, homologous chromosomes pair and crossing over occurs.
During __________, homologous chromosomes pair and crossing over occurs.
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Which blood type has no antigens present?
Which blood type has no antigens present?
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Codominance occurs when two alleles blend together to form an intermediate phenotype.
Codominance occurs when two alleles blend together to form an intermediate phenotype.
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List one method through which meiosis promotes genetic variation.
List one method through which meiosis promotes genetic variation.
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The process of __________ is crucial for producing sperm and occurs in the testes.
The process of __________ is crucial for producing sperm and occurs in the testes.
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Match the following blood types with their corresponding antibodies present:
Match the following blood types with their corresponding antibodies present:
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What occurs during telophase II of meiosis?
What occurs during telophase II of meiosis?
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In females, a sex-linked trait on the X chromosome can only express if both X chromosomes carry the recessive allele.
In females, a sex-linked trait on the X chromosome can only express if both X chromosomes carry the recessive allele.
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Define a pedigree chart.
Define a pedigree chart.
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During __________ I, independent assortment takes place.
During __________ I, independent assortment takes place.
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Flashcards
Mitosis
Mitosis
The process of one diploid cell producing two identical daughter cells. It's essential for growth and repair in organisms.
Meiosis
Meiosis
The process of one haploid cell dividing into two identical daughter cells, which then divide again to create four unique cells. It's essential for sexual reproduction and genetic diversity.
Diploid Cell
Diploid Cell
A cell containing the full set of chromosomes, usually represented as 2n. These cells make up most of your body.
Haploid Cell
Haploid Cell
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Somatic Cell
Somatic Cell
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Gamete
Gamete
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Gonads
Gonads
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Homologous Chromosomes
Homologous Chromosomes
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Punnett Square
Punnett Square
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Dihybrid Cross
Dihybrid Cross
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Multiple Alleles
Multiple Alleles
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Karyotype Chart
Karyotype Chart
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Zygote
Zygote
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True Breeding
True Breeding
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Hybrid
Hybrid
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Synapsis
Synapsis
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Tetrad
Tetrad
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Spermatogenesis
Spermatogenesis
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Oogenesis
Oogenesis
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Crossing Over
Crossing Over
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Pedigree Chart
Pedigree Chart
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Study Notes
Cell Cycle
- Consists of interphase, mitosis, and cytokinesis
- Used to replicate cells
- Duration varies from a couple of hours to a few days
Mitosis vs. Meiosis
- Mitosis: Creates two identical diploid daughter cells from one diploid cell
- Meiosis: Creates four genetically different haploid gametes from one diploid cell; two-stage cell division.
Cell Types
- Diploid cell: Somatic cells; contains 46 chromosomes (2n=46)
- Haploid cell: Gametes (sex cells); contains 23 chromosomes (n=23)
- Somatic cell: All body cells except gametes
- Gamete: Sex cells (sperm or egg)
- Gonads: Organs that produce gametes (ovaries and testes)
- Homologous chromosomes: Paired chromosomes similar in size, shape, and gene content; one from each parent
- Sister chromatids: Two copies of a chromosome joined at the centromere
Mendelian Genetics
- Independent assortment: Genes separate independently during gamete formation
- Crossing over: Exchange of genetic material between homologous chromosomes during prophase I of meiosis
- Nondisjunction: Failure of homologous chromosomes to separate during meiosis, potentially leading to chromosomal disorders
- Gene: Portion of a chromosome that controls traits; different forms are alleles
- Allele: Different forms of a gene
- Dominant allele: Expressed even if only one copy is present
- Recessive allele: Expressed only in homozygous genotype
- Homozygous: Two identical alleles
- Heterozygous: Two different alleles
- Chromatin: DNA and protein mixture forming chromosomes
- Genotype: Genetic makeup of an organism
- Phenotype: Observable characteristics of an organism
- Punnett Square: Table used to predict possible genotypes and phenotypes of offspring
- Monohybrid cross: Cross of two parents for a single gene trait
- Dihybrid cross: Cross of two parents for two genes traits
- Multiple alleles: Trait controlled by three or more versions of an allele
- Karyotype chart: Chart showing chromosome differences
- Chromosome: Shortened DNA rod
- Zygote: Fertilized egg (first cell formed from a sperm and egg)
- True-breeding (pure-breeding): Individuals that produce offspring with the same phenotype when breeding together
- Hybrid: Individuals with more than one trait variation
- Synapsis: Pairing of homologous chromosomes during prophase I of meiosis
- Tetrad: Four sister chromatids together during synapsis
- Spermatogenesis: Sperm cell production in testes
- Oogenesis: Egg cell production in ovaries
Mitosis and Meiosis Comparison
FeatureMitosisMeiosisNumber of divisions12Number of daughter cells24Genetically identical?YesNoChromosome numberSame as parentHalf of parentLocationSomatic cellsGerm cellsTimingThroughout lifeAt sexual maturityRoleGrowth and repairSexual reproduction
Meiosis Stages
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Prophase I: Homologous chromosomes pair, crossing over occurs, chromosomes condense, spindle forms, nuclear envelope disappears.
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Metaphase I: Homologous chromosomes align along the equator, independent assortment occurs
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Anaphase I: Homologous chromosomes separate and move to opposite poles.
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Telophase I: Nuclear envelopes re-form, spindle disappears, cytokinesis divides cell into two.
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Meiosis II: Only one homolog of each chromosome is present in the cell, Sister chromatids carry identical genetic information, produces gametes with one copy of each chromosome and thus one copy of gene.
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Prophase II: Nuclear envelope fragments, Spindle forms
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Metaphase II: Chromosomes align along the equator of the cell
Anaphase II: Sister chromatids separate and move to opposite poles
Telophase II: Nuclear envelope assembles, Chromosomes de condense, Spindle disappears, Cytokinesis divides cell into two
Genetic Variation in Meiosis
- Independent assortment: How the chromosomes line up at the equator during metaphase I
- Random fertilization: Sperm can fertilize any egg
- Crossing over: Exchange of genetic material between non-sister chromatids during prophase I after it becomes a tetrad
Inheritance of Traits
- Parents contribute one gene each; dominant trait masks recessive in heterozygotes
- Recessive trait expressed only in homozygous genotype
Complex Inheritance
- Incomplete dominance: Heterozygotes (equally dominant) show a blended phenotype; use superscripts
- Codominance: Both alleles are expressed equally in heterozygotes; use two letters
- Sex-linked traits: Genes on the X chromosome; males express recessive traits more often.
- Polygenic traits: Multiple genes influence a trait.
Pedigree Charts
- Visual representation of inheritance patterns in families
Blood Typing
- Blood type: Determined by antigens; associated antibodies presented
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Description
Test your knowledge on the cell cycle, including interphase, mitosis, and meiosis, as well as the differences between diploid and haploid cells. This quiz covers essential genetic concepts such as Mendelian genetics and chromosomal structures. Prepare to enhance your understanding of fundamental biological processes and terms!
