Skip to content
Login Register

#ploidy

3 public questions tagged with this topic.

Basics of Inheritance

Polyploidy refers to condition with

Polyploidy refers to condition carrying more than two chromosome sets, for example triploid 3n, tetraploid 4n, hexaploid 6n, arising via failure of mitotic or meiotic division or interspecific hybridisation. Autopolyploids duplicate same genome, allopolyploids combine distinct parental genomes. Extra dosage influences gene expression, cell size, fertility and adaptation, exploited in agriculture for wheat, potato and cotton. One set monoploid, two diploid, only sex chromosomes irrelevant, whole-genome multiplication represents major evolutionary mechanism. Understanding this mechanism aids pedigree analysis, Punnett predictions, linkage mapping and appreciating evolutionary conservation across taxa.

Ref: Snustad & Simmons, Principles of Genetics, 7th ed., Chapter 9: Polyploidy

View Details
Basics of Inheritance

Diploid organisms contain

Diploid organisms maintain two complete chromosome sets, designated 2n, in somatic cells with homologous pairs one inherited from each parent. This state provides two allelic copies per locus, permitting dominance interactions, buffering deleterious recessives and enabling segregation. Diploidy is restored at fertilisation when haploid gametes fuse and reduced during meiosis maintaining constant chromosome number across generations. One set defines monoploid, three sets triploid and variable sets describe mixoploidy or aneuploidy, diploid condition dominates animal life cycles. This principle is routinely tested in NEET, CBSE 11-12, CUET, CSIR-NET, GATE and MSc Genetics examinations requiring clear conceptual distinction.

Ref: Pierce, Genetics, 7th ed., Chapter 2: Diploidy and Life Cycles

View Details
Basics of Inheritance

Monoploid organisms contain

Monoploid organisms contain single complete chromosome set, symbol n, representing basic genome. Naturally monoploid states include prokaryotes, gametes of diploids, some fungi and lower plants. They express every allele without masking by dominance, facilitating mutational screens and genetic analysis. Two sets define diploid 2n, three triploid, four tetraploid. Monoploid terminology overlaps haploid, which references reduced gametic number relative to somatic diploid. Understanding monoploidy clarifies ploidy cycles, life cycles and origin of alternation of generations in plants. Cytological correlation with prophase pairing, metaphase alignment and anaphase separation provides visual anchor for memorising genetic laws.

Ref: Griffiths et al., Introduction to Genetic Analysis, 12th ed., Chapter 3: Ploidy, Monoploid

View Details