Following statements are regarding to the CFTR.

A. cystic fibrosis transmembrane conductance regulator allows Cl− ions to flow out of the cell, following their concentration gradient.

B. ATP binding to CFTR’s two nucleotide-binding domains appears to close the Cl− channel, and the hydrolysis of one ATP opens it (the other ATP remains intact).

C. the CFTR channel can open only if its regulatory domain (which is unique among ABC transporters) has been phosphorylated, thus regulating the flow of ions across the membrane.

D. The maintenance of electrical neutrality requires that the Cl− ions transported by the CFTR be accompanied by positively charged ions, mainly Na+. The transported ions are osmotically accompanied by water, thus maintaining the proper level of fluidity in secretions of the airways, intestinal tract, and the ducts of the pancreas, testes, and sweat glands.

Which of the following combination is correct?

#Question id: 4897

#Unit 8. Inheritance Biology

When two independent pure lines AAbb and aaBB of pea with white flowers are crossed, the F1 progeny has purple flowers. Gene A and B link at 20 map unit. The following conclusions were made

A. When an heterozygous individual of the genotype AaBb is test crossed, progenies with purple and white in a ratio of 1:3

B. When an heterozygous individual of the genotype AaBb is test crossed, progenies with purple and white in a ratio of 1:9

C. This is an example of complementary gene action

D. The F2 progeny obtained on selfing shows both pruple and white flower in a ratio of 9:7                                            

Which of the following conclusions are correct?

#Question id: 4898

#Unit 8. Inheritance Biology

A three point test cross was carried out in Drosophila melanogaster involving three adjacent genes A, B and C. arranged in the same order. The distance between A to B is 15 map unit (mu) and that between B to C is 30 map. The coefficient of coincidence = 0.67. What is the percentage of double recombinants in the progeny obtained from the testcross?

#Question id: 4899

#Unit 8. Inheritance Biology

In Neurospora a cross between the genotypes 'A' and 'a' results in an ascus with ascospores of genotypes as shown below: 

 Statements A to D are events that could have occurred during meiosis.

A) Class I is results of no crossing over between the centromere and gene.

B) Class II is results of single crossing over between the centromere and gene

C) Class I shows segregation of alleles 'A' and 'a' in meiosis II

D) Class II shows segregation of alleles 'A' and 'a' in meiosis II

#Question id: 4900

#Unit 8. Inheritance Biology

The chlorophyll-deficient types occur in a particular plant species due to a mutation in the DNA of the chloroplast itself, Female cytoplasm chlorophyll-deficient organisms crossed with male normal chlorophyll will produce progeny

#Question id: 4900

#Unit 8. Inheritance Biology

The chlorophyll-deficient types occur in a particular plant species due to a mutation in the DNA of the chloroplast itself, Female cytoplasm chlorophyll-deficient organisms crossed with male normal chlorophyll will produce progeny

#Question id: 4901

#Unit 8. Inheritance Biology

Assume that the alleles A (dominant) and a (recessive) show a maternal effect mode of inheritance. In a cross between an Aa female and an aa male, what would be the phenotypes of the progeny?