Sign up now
to enroll in courses, follow best educators, interact with the community and track your progress.
Download
Incomplete dominance
2,584 plays

More

Dr Praveen Kumar Agrawal is teaching live on Unacademy Plus

Dr Praveen Kumar Agrawal
Ex - Faculty, Allen Kota, 22 Yrs Experience. Author - 17 books Known for best explanation Youtube : Concept Gurukul

U
Unacademy user
thanks dipesh ..
Dipesh Saini
2 years ago
:)
great explanation. god of biology
👍👍👍👍👍👍👍👍👍👍👍👍👍👍🤩🤩🤩🤩🤩🤩🤩🤩🤩🤩🤩🤩
sir I am poor very much but I have dream become a doctor sir thanks very much sir.best explaination
Thanks. Padhte raho
Sir u skipped dihybrid cross
  1. COURSE Principles of inheritance and variations Lesson 11 A Critical evaluation of Mendel's Laws Incomplete Dominance Dr. Praveen Kumar Agrawal M.Sc., Ph.D., CSIR NET (JRF). SRF, GATE 21Years of Pre-medical teaching experience


  2. UNACADEMY LIVE NOW SUBSCRIBE FOR ALL LIVE/PLUS COURSES Of ALL EDUCATORS IN PRE MED CATEGORY ONLY FOR A NOMINAL FEE Use following referral code for EXTRA 10% REBATE biologybypkagrawal-6909


  3. 1. INCOMPLETE DOMINANCE According to Mendel's first principle, in F1 generation or in heterozygous state, only one allele is able to express itself phenotypically, while other remains suppressed. Further, the two alleles do not show any interaction. However, in Mirabilis jalapa (4 'O' clock plant), or in Antirrhinium majus (Snapdragon), when a cross is made between pure white and red flowered plants, all F1 individuals have pink flower. (According to Mendel there should have been either white or red flowers) (phenotypic ratio). (However, according to Mendel, the F2 phenotypic ratio should be 3: 1). dominance of one allele over the other allele is not complete or perfect. On selfing, these pink flowered F1 individuals produced red, pink and white flowered plants in 1: 2: 1 The appearance of pink flower in heterozygous condition suggested that in some cases, the Therefore, both alleles interact with each other and produce a mixed or blended character. the blending of the character is called incomplete dominance (or blending inheritance) dominance. This type of inheritance where the two alleles of a character interact in such a way, so as to cause The incomplete dominance clearly and directly opposes the universality of the Mendel's principle of


  4. Red White R r R r Pink Pink Pink Pink F1 generation


  5. Pink Pink Red Pink Pink White F 2 generation


  6. Another Example of Incomplete Dominance Starch synthesis in pea seeds is controlled by one gene. It has two alleles (B and b). Starch is synthesised effectively by BB homozygotes and therefore, large starch grains are produced. On the other hand, bb homozygotes have lesser efficiency in starch synthesis and produce smaller starch grains. After maturation of the seeds, B seeds are round and the b seeds are wrinkled. Heterozygotes (Bb) produce round seeds, and so B seems to be the dominant allele. But, the starch grains produced are of intermediate size in Bb seeds. So, if starch grain size is considered as the phenotype, then from this angle, the alleles show incomplete dominance. This case is also an example of pleiotropy because same gene B is determining more than one trait, i.e., seed shape and seed size.


  7. WATCH MY LIVE Course Watch my live course in Unacademy Plus section. Actual classroom feel at your home and live doubt removal .Go to www.unacademy.com/plus. Search for my live course and get yourself registered. ALL THE BEST