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Genotype [ Biology - Genetics ]
Synonym: Genetic make up.
Adjective:  Genotypic
Adverb: Genotypically

Dictionary of botanic terminology - index of names

     
  The genes of an organism. The inherited genetic code of an organism for a specific trait.  
     
  The genotype is the genetic makeup of an organism or set of DNA variants found at one or more loci in an individual, as characterized by its physical appearance or phenotype. The allelic composition of an individual. The external features -what scientists call phenotypes- are different. Most organism have a wide array of genetic trait (colour, shape etc.). However the interior profile, or genotype - the organization of the genes in the chromosomes- identifies each species. For a single trait on an autosome, an individual can be homozygous for the dominant trait, heterozygous, or homozygous for the recessive trait. (e.g. In a species the yellow flower (trait) is dominant, but yellow flowerd plants could have a genotype of either YY or Yy)
Genotype is a pattern of genetic information that is unique to an individual or group.

Compare with: Phenotype
 
 

 


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Holdfast roots  [ Botany  ]

Dictionary of botanic terminology - index of names

 
     
  Some species of climbing plants develop holdfast roots which help to support the vines on trees, walls, and rocks. By forcing their way into minute pores and crevices, they hold the plant firmly in place.  
     
Climbing plants, like the poison ivy (Toxicodendron radicans), Boston ivy (Parthenocissus tricuspidata), and trumpet creeper (Campsis radicans),  develop holdfast roots which help to support the vines on trees, walls, and rocks. By forcing their way into minute pores and crevices, they hold the plant firmly in place. Usually the Holdfast roots die at the end of the first season, but in some species they are perennial. In the tropics some of the large climbing plants have hold-fast roots by which they attach themselves, and long, cord-like roots that extend downward through the air and may lengthen and branch for several years until they strike the soil and become absorbent roots.

Major references and further lectures:
1) E. N. Transeau “General Botany” Discovery Publishing House, 1994
     

 

 

 

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