Retinoblastoma usually occurs as a sporadic event but in around 10% of cases there is a positive family history due to autosomal dominant inheritance. In these families the penetrance is approximately 80% (= 0.8). A woman with retinoblastoma, whose father and grandfather were also affected, has an unaffected partner with no relevant family history. Which of the following is correct regarding their children?

#Question id: 4906

#Part-A Aptitude & General Biotechnology

Shell coiling is a maternal effect phenotype controlled by S gene where S is dominant dextral phenotype over s sinistral phenotype. Dextral coiling Ss male snail was cross with sinistral coiling ss female snail, The phenotype of progeny is 

#Question id: 4907

#Part-A Aptitude & General Biotechnology

Two corn plants are studied. One is resistant (R) and the other is susceptible (S) to a certain pathogenic fungus. The following crosses are made, with the results shown

R male X S female = all S progeny

R female X S male = all R progeny

Which of the following are correct about inheritance?

#Question id: 4908

#Part-A Aptitude & General Biotechnology

Shell coiling of the snail is maternal effect phenotype control by S gene, where S Dextral is dominant over s sinistral. If snail sinistral coiled shell, which of the following statement is true

#Question id: 4909

#Part-A Aptitude & General Biotechnology

A pattern of transmission where all offspring have the same phenotype as their mother is consistent with which type of non-Mendelian inheritance?

#Question id: 4910

#Part-A Aptitude & General Biotechnology

For a trait known to be caused by a mitochondrial gene variant, there may be an occasional female that can transmit different phenotypes to her progeny on an apparently random basis. What situation might you suspect?

#Question id: 4911

#Part-A Aptitude & General Biotechnology

Neutral petite mutations: