2n = 6.
Homologous chromosomes separate and move towards opposite poles, while sister chromatids remain attached at the centromere.
They disintegrate.
They are attached to the centromeres via the kinetochore.
The sister chromatids of each chromosome will not be genetically identical.
Centromeres divide, and sister chromatids separate and move towards opposite poles.
Due to the billions of sperm and hundreds of eggs produced, leading to vast genetic variation.
Chromatin.
They disintegrate.
The nuclear envelope and nucleolus.
A change in chromosome number, leading to aneuploidy or polyploidy.
DNA is replicated during the S phase of interphase, resulting in chromosome duplication.
A cell with 2 sets of chromosomes (2n), one set from each parent.
Haploid gametes fuse to restore the diploid number of chromosomes.
Chromosomes reach opposite poles.
Pairs of homologous chromosomes (bivalents) are arranged along the equator (metaphase plate).
Centrioles.
4 daughter nuclei.
Two cycles: Meiosis I and Meiosis II.
Alterations in the structure or number of chromosomes, including numerical aberrations like aneuploidy and structural aberrations like translocation, duplication, inversion, and deletion.
23 chromosomes.
When the nucleus has divided during telophase I and II or when the cell has divided during cytokinesis.
There is a breakage and re-joining of DNA molecules in the non-sister chromatids, resulting in an exchange of genetic materials.
Cells enter a brief interphase.
4 haploid daughter cells (gametes).
The random fusion of male and female gametes from each parent.
A genetically variable zygote, leading to genetically variable offspring.
Spindle fibers are attached to the centromeres of the chromosomes via the kinetochore.
Chiasmata are formed between the non-sister chromatids of a pair of homologous chromosomes.
When sister chromatids separate during anaphase II.
New combinations of alleles in the non-sister chromatids, which become chromosomes of the daughter cells.
The random orientation of bivalents at the equator during metaphase I, leading to random separation of homologous chromosomes.
During the formation of gametes (e.g., sperm and ovum).
A change in the nucleotide sequence of a gene, which can involve substitution, addition, or deletion of nucleotides.
Aneuploidy, such as trisomy 21 (Down syndrome).
It prevents the doubling of chromosomes by producing haploid gametes.
A distinct 'V' shape.
Formation of haploid gametes due to the separation of homologous chromosomes during anaphase I.
Chiasmata enable crossing over between non-sister chromatids.
Prophase I.
Thread-like chromatin.
Reduction division.
Each daughter cell is genetically different from the parent cell and from each other.
23.
2^23.
Through processes like crossing over and independent assortment.
A bivalent (or tetrad) is formed by a pair of homologous chromosomes.
It decreases when the nucleus has divided during telophase I and II or when the cell has divided during cytokinesis.
It is halved during the formation of gametes.
It decreases from 6 to 3.
Homologous chromosomes reach opposite poles, spindle fibers disintegrate, and the nuclear envelope reforms, resulting in 2 daughter nuclei.
Centrioles move to opposite poles and spindle fibers form.
Homologous chromosomes pair up and exchange genetic material through crossing over.
DNA replicates.
High-pitched cry, intellectual disability, delayed development, small head size, low birth weight, and weak muscle tone.
2^n, where n is the number of homologous pairs.
Centrioles move to opposite poles and spindle fibers form.
Along the equator or metaphase plate.
It prevents the doubling of chromosomes in sexual reproduction and generates genetic variation.
Synapsis is the process where homologous chromosomes pair up.
Four genetically diverse haploid cells.
They may become intertwined, leading to structural aberrations.
A type of nuclear division that forms 4 genetically different daughter nuclei, each with half the number of chromosomes of the parent cell.
Chromosomes form a distinct 'V' shape with centromeres pointing towards opposite poles.
Haploid, with only 1 set of chromosomes.
2^n, where n is the number of chromosomes per gamete.
Meiosis I and Meiosis II, which include prophase, metaphase, anaphase, and telophase for each.
Meiosis (crossing over and independent assortment) and random fusion of gametes.
Non-sister chromatids may contain new combinations of alleles due to the exchange of genetic materials.
6 chromosomes.
Cri du chat syndrome.
The direction in which each chromosome faces in a bivalent is independent of the other bivalents.
No, there is no S phase or DNA replication prior to meiosis II.
It results in non-identical sister chromatids due to the exchange of genetic materials, increasing genetic variation.
Genetically variable gametes.
A cell with 1 set of chromosomes (n), such as gametes formed at the end of meiosis.
Pairs of chromosomes that come from each parent in a diploid cell.
They are now considered individual chromosomes.
Chiasmata between homologous chromosomes.
Pairs of chromosomes that have the same size, with centromeres in the same position, and the same genes arranged in identical sequences.
3 chromosomes.
Failure in the separation of homologous chromosomes in anaphase I or sister chromatids in anaphase II.
Different combinations of homologues result in different combinations of alleles in the gametes.
The number of sets of chromosomes in the nucleus of a cell.
Chromatin condenses into chromosomes, while the nucleolus and nuclear envelope disintegrate.
The fusion of male and female gametes would result in a doubling of the chromosome number for each successive generation.
The exchange of genetic materials between non-sister chromatids of homologous chromosomes during prophase I.
They pair up during meiosis, allowing for genetic recombination and independent assortment.
By creating new combinations of alleles in gametes.
Only when DNA replicates during the S phase.
