Meioses Flashcards
What is meiosis?
Meiosis is a type of cell division that reduces the chromosome number by half, producing four haploid cells from one diploid cell.
How many stages are there in meiosis?
There are two stages in meiosis: meiosis I and meiosis II.
True or False: Meiosis results in two identical daughter cells.
False: Meiosis results in four genetically diverse daughter cells.
What type of cells undergo meiosis?
Germ cells undergo meiosis to produce gametes.
Fill in the blank: Meiosis involves two rounds of division known as _____ and _____.
meiosis I and meiosis II.
What occurs during prophase I of meiosis?
Chromosomes condense, homologous chromosomes pair up, and crossing over occurs.
What is crossing over?
Crossing over is the exchange of genetic material between homologous chromosomes during prophase I.
What is the result of meiosis I?
The result of meiosis I is two haploid cells, each with half the number of chromosomes.
True or False: Meiosis II is similar to mitosis.
True: Meiosis II resembles mitosis, separating sister chromatids.
What is the final product of meiosis?
The final product of meiosis is four genetically diverse haploid cells.
In which phase do homologous chromosomes separate?
Homologous chromosomes separate during anaphase I.
What is the purpose of meiosis?
The purpose of meiosis is to produce gametes for sexual reproduction and to ensure genetic diversity.
Fill in the blank: During _____, sister chromatids are pulled apart.
anaphase II.
What is a tetrad?
A tetrad is a structure formed during prophase I, consisting of a pair of homologous chromosomes.
True or False: Meiosis occurs in somatic cells.
False: Meiosis occurs in germ cells, not somatic cells.
What is synapsis?
Synapsis is the process where homologous chromosomes pair up during prophase I.
What is the term for the genetic variation introduced during meiosis?
Genetic recombination.
How does meiosis contribute to genetic diversity?
Meiosis contributes to genetic diversity through crossing over and independent assortment.
Fill in the blank: The exchange of segments between non-sister chromatids is called _____.
crossing over.
What is the significance of independent assortment?
Independent assortment leads to the random distribution of maternal and paternal chromosomes into gametes.
During which phase does the nuclear envelope reform?
The nuclear envelope reforms during telophase II.
What is the role of spindle fibers in meiosis?
Spindle fibers help separate chromosomes during cell division.
True or False: Meiosis results in diploid cells.
False: Meiosis results in haploid cells.
What are gametes?
Gametes are reproductive cells (sperm and eggs) produced through meiosis.
What is a homologous chromosome?
Homologous chromosomes are pairs of chromosomes, one from each parent, that have the same genes but may have different alleles.
Fill in the blank: The number of chromosomes in a human gamete is _____.
23.
What happens during anaphase I?
Homologous chromosomes are pulled apart to opposite poles of the cell.
What is the difference between meiosis and mitosis?
Meiosis results in four genetically diverse haploid cells, while mitosis produces two identical diploid cells.
What is the role of the centromere during meiosis?
The centromere holds sister chromatids together and is the attachment point for spindle fibers.
True or False: All organisms undergo meiosis.
False: Not all organisms undergo meiosis; some reproduce asexually.
What is the term for the first division of meiosis?
Meiosis I.
What occurs during metaphase I?
Homologous chromosome pairs align at the cell’s equatorial plate.
What is the outcome of meiosis II?
Meiosis II results in the separation of sister chromatids, producing four haploid cells.
Fill in the blank: The process of meiosis is essential for _____ reproduction.
sexual.
What is the role of chiasmata?
Chiasmata are points where homologous chromosomes exchange genetic material during crossing over.
What is the difference between haploid and diploid?
Haploid cells have one set of chromosomes, while diploid cells have two sets.
During which phase of meiosis does crossing over occur?
Crossing over occurs during prophase I.
What is the term for the second division of meiosis?
Meiosis II.
True or False: The genetic makeup of the daughter cells in meiosis is identical to the parent cell.
False: The daughter cells are genetically different from the parent cell.
What is the role of the meiotic spindle?
The meiotic spindle helps segregate chromosomes during cell division.
What are the two main phases of meiosis?
Meiosis I and meiosis II.
Fill in the blank: The process of forming gametes is called _____.
gametogenesis.
What is the main purpose of meiosis?
To create genetic diversity and produce gametes for sexual reproduction.
What happens during telophase I?
The cell divides into two haploid cells, and the nuclear envelope may reform.
True or False: Meiosis occurs in both plants and animals.
True: Meiosis occurs in both plants and animals.
What is a gametophyte?
A gametophyte is a haploid stage in the life cycle of plants that produces gametes.
Fill in the blank: In humans, meiosis produces _____ and _____.
sperm and eggs.
What occurs during cytokinesis in meiosis?
Cytokinesis divides the cytoplasm, resulting in separate daughter cells.
What is the significance of genetic variation in populations?
Genetic variation increases the adaptability and survival of populations.
What is a diploid organism?
A diploid organism has two complete sets of chromosomes, one from each parent.
What is the role of meiosis in evolution?
Meiosis contributes to evolution by generating genetic diversity through recombination and independent assortment.
True or False: Independent assortment occurs during meiosis I.
True: Independent assortment occurs when homologous chromosomes are separated.
What is the term for a cell with a single set of unpaired chromosomes?
Haploid cell.
Fill in the blank: The process of meiosis occurs in the _____ of organisms.
gonads.
What is the primary goal of meiosis?
To produce gametes for sexual reproduction.
What is a polar body?
A polar body is a small haploid cell that is a byproduct of oogenesis and typically does not develop into a gamete.
True or False: Meiosis results in genetic clones of the parent cell.
False: Meiosis results in genetically diverse cells.
What is the significance of the first meiotic division?
The first meiotic division reduces the chromosome number and allows for genetic variation.
What leads to the formation of aneuploidy?
Errors during meiosis, such as nondisjunction, can lead to aneuploidy.
Fill in the blank: The process of chromosome pairing and exchange during meiosis is called _____.
homologous recombination.
What are the two types of gametes produced by meiosis in humans?
Sperm and eggs.
What happens to the chromosome number during meiosis?
The chromosome number is halved from diploid to haploid.
Fill in the blank: The meiotic process ensures that offspring have the same number of chromosomes as their _____ parents.
diploid.
What is the role of the meiotic spindle apparatus?
The meiotic spindle apparatus organizes and separates chromosomes during meiosis.
What is the term for a cell that contains two sets of chromosomes?
Diploid cell.
True or False: Each gamete carries a full set of chromosomes.
False: Each gamete carries half the number of chromosomes.
What is the function of meiosis in plants?
Meiosis in plants produces spores that develop into gametophytes.
Fill in the blank: The cell division that produces gametes is called _____.
meiosis.
What is a zygote?
A zygote is the fertilized egg formed by the union of two gametes.
What is the role of genetic diversity in a population?
Genetic diversity enhances survival and adaptability to changing environments.
What is the difference between oogenesis and spermatogenesis?
Oogenesis is the formation of egg cells, while spermatogenesis is the formation of sperm cells.
True or False: All four daughter cells produced by meiosis develop into functional gametes.
False: In oogenesis, usually only one functional egg is produced, and the rest are polar bodies.
What is the significance of the second meiotic division?
The second meiotic division separates sister chromatids, ensuring genetic variation.
Fill in the blank: The process of meiosis is crucial for the maintenance of _____ in sexually reproducing organisms.
chromosome number.
What are the phases of meiosis I?
Prophase I, Metaphase I, Anaphase I, and Telophase I.
What are the phases of meiosis II?
Prophase II, Metaphase II, Anaphase II, and Telophase II.
Fill in the blank: During meiotic prophase I, chromosomes undergo _____ to form tetrads.
synapsis.
What is the role of the centrioles during meiosis?
Centrioles help organize the spindle fibers required for chromosome separation.
True or False: Meiosis can occur in organisms that reproduce asexually.
False: Meiosis is primarily associated with sexual reproduction.
What is the result of nondisjunction during meiosis?
Nondisjunction can lead to aneuploidy, resulting in cells with an abnormal number of chromosomes.
Fill in the blank: The genetic variation in gametes is a result of _____ and _____.
crossing over and independent assortment.
What is the term for the physical location of a gene on a chromosome?
Locus.
What is the difference between a gamete and a zygote?
A gamete is a haploid reproductive cell, while a zygote is a diploid cell formed by the fusion of two gametes.
Fill in the blank: The process that leads to the formation of sperm cells is called _____.
spermatogenesis.
What is the role of DNA replication in meiosis?
DNA replication occurs before meiosis begins to ensure each chromosome consists of two sister chromatids.
True or False: Genetic recombination occurs during meiosis II.
False: Genetic recombination occurs during meiosis I.
What is the main difference between mitosis and meiosis in terms of genetic outcome?
Mitosis produces identical cells, while meiosis produces genetically diverse cells.
What is the term for the process of forming eggs?
Oogenesis.
Fill in the blank: During _____, homologous chromosomes are randomly assorted into daughter cells.
metaphase I.
What is the significance of the second meiotic division?
It separates sister chromatids, ensuring that each gamete receives one copy of each chromosome.
What is the term for a cell with three copies of a chromosome?
Trisomy.
True or False: Meiosis occurs in all eukaryotic organisms.
False: Meiosis occurs primarily in organisms that reproduce sexually.
What is the role of the nuclear envelope during meiosis?
The nuclear envelope breaks down to allow spindle fibers to access chromosomes.
What is a secondary oocyte?
A secondary oocyte is an egg cell that has completed meiosis I but not meiosis II.
Fill in the blank: The process of meiosis begins with a _____ cell.
diploid.
What is the term for the fusion of male and female gametes?
Fertilization.
True or False: The primary purpose of meiosis is to produce somatic cells.
False: The primary purpose of meiosis is to produce gametes.
What is the term for the chromosome number in gametes?
Haploid.
Fill in the blank: The meiotic process increases _____ among offspring.
genetic diversity.
What is a tetrad?
A tetrad is a pair of homologous chromosomes that align together during prophase I.
What is the significance of meiosis in sexual reproduction?
Meiosis ensures that offspring inherit genetic material from both parents, promoting diversity.
Fill in the blank: The union of two gametes results in a _____ cell.
diploid.
What is the role of the zona pellucida?
The zona pellucida is a glycoprotein layer that surrounds the oocyte and is involved in fertilization.
True or False: Meiosis produces cells that are genetically identical to the parent cell.
False: Meiosis produces genetically diverse cells.
What is the term for the genetic exchange that occurs during meiosis?
Genetic recombination.
Fill in the blank: The first meiotic division separates _____ chromosomes.
homologous.
What is the role of the ovary in meiosis?
The ovary is the organ where oogenesis occurs and eggs are produced.
What is the end result of oogenesis?
The end result of oogenesis is one functional egg and three polar bodies.
True or False: Meiosis can lead to genetic disorders if errors occur.
True: Errors during meiosis can result in genetic disorders.
What is the purpose of the second meiotic division?
To separate sister chromatids into individual haploid cells.
Fill in the blank: During fertilization, a sperm and egg unite to form a _____ cell.
zygote.
What is the term for the reduction of chromosome number during meiosis?
Reductional division.
True or False: Both meiosis I and meiosis II include prophase, metaphase, anaphase, and telophase.
True: Both divisions include these phases.
What is the role of the follicle in oogenesis?
The follicle supports the growth and maturation of the oocyte.
What is the importance of genetic variation for a species?
Genetic variation allows for adaptation to changing environments and increases survival chances.
Fill in the blank: In animals, meiosis produces _____ for reproduction.
gametes.
