Heteromorphic types - intra specific incompatibility, Biology

Assignment Help:

Heteromorphic Types - Intra specific Incompatibility

Plants of the same species produce flowers that differ in morphology. This involves two (distyly) or three (tristyly) morphologically distinct types of flowers showing similar breeding behavior (mating type) within a species. The difference in the mating types lies in the position of stigma and anthers (heterostyly). Distyly is under the control of a single gene complex with two alleles, S (for short style-dominant) and s (for long style-recessive). Long style individuals are, therefore, homozygous recessive (ss) and short style are heterozygous (Ss). This ensures approximately equal ratio of short and long-styled individuals from compatible crosses.

Tristyly refers to three floral morphs with individuals having either long, mid- or short- styled flowers. Each type has stamens of two heights corresponding to the height of stigma in the other two forms. Successful pollination results only between forms having stigma and stamens of the same height. Two genes, M and S with two alleles each control tristyly. Gene S is epistatic to M. Homozygous recessive for both the genes (ssmm) determine long style, mid-style have ssMM or ssMm and short-styled flowers carry the genes SsMm or Ssmm or SsMM. In both di- and trimorphic forms sporophytic incompatibility operates.


Related Discussions:- Heteromorphic types - intra specific incompatibility

Determine the parts of sphygmomanometer, Determine the Parts of sphygmomano...

Determine the Parts of sphygmomanometer Parts of sphygmomanometer consists of: - an inflatable cuff (wrapped around the arm when checking B.P) at vertical height as the hear

Explain the dietary management of a lactating mother, Explain the Dietary M...

Explain the Dietary Management of a lactating mother? Meeting the needs of lactation requires a varied nutrient-dense diet. Generally, a well-balanced diet will meet nutrient n

Explain the food applications of guar, Explain the Food Applications of gua...

Explain the Food Applications of guar Guar imparts smoothness to ice cream by promoting small ice crystals during the freezing process. Guar gum in the dressing of cot

Show some fungal diseases transmitted by animal feces, Q. What are some fun...

Q. What are some fungal diseases transmitted by animal feces? Pigeon and Bat feces can carry Histoplasma capsulatum, the fungus agent of histoplasmosis. The infection is transm

What does radial symmetry means, Q. What does radial symmetry means? What i...

Q. What does radial symmetry means? What is the kind of symmetry found in chordates? Which are other phyla of the animal kingdom that present species with radial symmetry? Radi

Functions based on management principles, FUNCTIONS BASED ON MANAGEMENT PRI...

FUNCTIONS BASED ON MANAGEMENT PRINCIPLES: Planning: The objectives of nursing unit should be achieved through planning, good coordination and supervision. While planning nur

Genomic dna from the sea urchin, Eric Davidson isolated and compared the se...

Eric Davidson isolated and compared the sequences of mRNA transcripts and genomic DNA from the sea urchin. Which of the following is a true statement regarding his findings? A.

Coelenterata, mode of digestion in coelenterata

mode of digestion in coelenterata

What is short acting insulin, Q. What is Short acting insulin? Short ac...

Q. What is Short acting insulin? Short acting: This type of insulin begins working quickly, works hardest 2- 3 hours after injection but is completely gone after 4-6 hrs. So if

Definition of biological diversity, Q. Definition of Biological diversity? ...

Q. Definition of Biological diversity? Biological diversity has no single standard definition. One definition holds that biological diversity is a measure of the relative diver

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd