polymorphism

/,pɔli'mɔ:fizm/

Thân thiện

A single butterfly species exhibits polymorphism, with individuals showing different wing patterns.

Definition

1. Noun:
   • (Biology): The occurrence of two or more distinct forms or morphs within the same species, independent of differences in sex.
   • (Chemistry): The property of a chemical compound to crystallize in two or more different forms, resulting in distinct crystal structures.
   • (Genetics): The presence of genetic variation (multiple alleles) at a specific locus within a population, providing the raw material upon which natural selection can act.

Usage Examples

• Noun (Biology):
  • The polymorphism in the butterfly species allows some individuals to mimic leaves while others have bright warning colors.
  • Sexual dimorphism is a specific type of polymorphism.
• Noun (Chemistry):
  • Carbon exhibits polymorphism, existing as both graphite and diamond.
  • Studying the polymorphism of a pharmaceutical compound is crucial for drug stability.
• Noun (Genetics):
  • Single nucleotide polymorphism (SNP) is a common type of genetic polymorphism.
  • The high degree of polymorphism in the MHC genes is vital for immune system function.

Advanced Usage

• "Balanced polymorphism": A situation in which natural selection maintains multiple alleles at a locus over many generations.
  • Sickle cell trait is a classic example of balanced polymorphism due to the heterozygote advantage against malaria.
• "Transient polymorphism": A temporary state of polymorphism occurring while one allele is replacing another in a population.
  • The spread of a new, advantageous allele creates a period of transient polymorphism.

Variants and Related Words

• Polymorphic (adj): Existing in, or taking on, multiple forms.
  • The species is highly polymorphic, with dozens of documented color patterns.
• Polymorph (n): One of the distinct forms existing within a polymorphic species or compound.
  • The white morph is the rarest polymorph of the Arctic fox.

Synonyms

• Pleomorphism: Often used interchangeably in biology, though it can sometimes imply a greater number of forms.
• Multiplicity of forms: A descriptive phrase for the general concept.
• Genetic variation: A broader term closely related to the genetic sense of polymorphism.

Related Phrases

• "Single nucleotide polymorphism (SNP)": A substitution of a single nucleotide at a specific position in the genome, representing the most common type of genetic variation.
  • Researchers identified a SNP associated with increased risk for the disease.
• "Restriction fragment length polymorphism (RFLP)": A difference in DNA sequences that results in DNA fragments of different lengths when cut by restriction enzymes.
  • RFLP analysis was an early technique used in DNA fingerprinting.

Related Idioms

(Note: As a technical/scientific term, 'polymorphism' is not commonly used in idiomatic expressions. Its usage is primarily literal and academic.)

Học thuật

Noun

1. (biology) the existence of two or more forms of individuals within the same animal species (independent of sex differences)
2. (chemistry) the existence of different kinds of crystal of the same chemical compound
3. (genetics) the genetic variation within a population that natural selection can operate on

Từ đồng nghĩa

• pleomorphism