Explore topic-wise InterviewSolutions in Current Affairs.

D. electroscope 

Electroscope is the device which is used to detect charge on a body. It is used for detecting, measuring and finding the nature of a charge.

d) Distilled water 

The Right option is : (a) charged

During lightning actually Electric discharge takes place.

1. Incomplete dominance

2. 1:2:1

B , Genotype A: B:C:D: = 3:1:9:3 OR 9:3:3:1

Morgan observed the result of linkage of genes on a chromosome, but Mendel did not observe phenomenon of linkage in pea plants // F₂ ratio of Morgan deviated significantly from 9 : 3 : 3 : 1 ratio (Mendelian ratio).

Answer is (b) 1:1

c) Tin is less reactive than iron. 

A device used to test whether an object is carrying charge or not is called  Electroscope.

Correct option is C) Electroscope

A) 1 – e, 2 – c, 3 – b, 4 – a, 5 – d

(a) non-Mendelian inheritance

Answer is (c) 400

It is a convention to call the charge acquired by a glass rod when it is rubbed with silk as Positive.

Correct option is B) Negative

(d) similar phenotypic and genotypic ratio of 1:2:1

Thomas Hunt Morgan put forth chromosome theory of linkage from his work on fruit fly (Drosophila melanogaster). He established the principle of linkage, discovered sex linkage and technique of chromosomal mapping. He wrote a book Theory of gene’ and was awarded Nobel Prize in 1933.

1. Yes, in incomplete dominance intermediate character appears and neither character is completely dominant over the other.

2. In law of dominance, in a heterozygous pair of factors one member of the pair dominates (dominant) the other (recessive).

After rubbing the glass rod with silk cloth, the glass rod becomes positively charged. The silk cloth becomes negatively charged.

Father ( A + XY)

Mother ( A + XX^h)

Son ( A + X^hY)

(A = Autosomes which are 44 in number & XY Sex chromosomes).

(i) Hb^A, Hb^S 

(ii) Hb^S Hb^S

Mutation arising due to change in single base pair of DNA, the defect is caused by the substitution of Glutamic acid (Glu) by Valine (Val) at the sixth position of the beta globin chain of the haemoglobin molecule.

(i) Turner's syndrome. 

(ii) 44 with XO chromosomes - such females are sterile as ovaries are rudimentary. Other features include lack of other secondary sexual characters, short stature and under developed feminine characters.

1- Henking- He gave the importance of X body transfer in spermatogenesis of insects

2 – T.H. Morgan – Morgan gave the importance of physical association or linkage of the two genes and coined the term linkage.

3 – Sutton & Boveri – He gave the importance of the pairing and separation of a pair of chromosomes would lead to the segregation of a pair of factors they carried, it is called chromosomal theory of inheritance.

A diploid organism has only two alleles of a character, although it has more than two alleles. Multiple alleles can be found only when population studies are made.

ABO blood group is controlled by more than two alleles — I^A , I^B and i. A group I^A I^A ,I^A ,i, B group—I^B I^B , I^B i , AB group I^A , I^B , O group – ii

In AB blood group both I^A and I^B alleles behave as dominant genes, producing both A and B antigens.

Multiple allelism: Generally in an individual or population, only two alleles of a trait govern the character, but in case of ABO blood group, three alleles I^A, I^B and i are found to govern blood group in human population. This is multiple allelism. Co-dominance: Allele I^A and I^B when present in an individual, both being dominant express their own types of sugars or traits. Thus, exhibiting co-dominance.

Diploid individual has only two sets of homologous chromosomes hence only two alleles of a gene can be present on homologous pair of chromosome.

B. the glass rod becomes positively charged while the silk cloth has a negative charge. 

After rubbing the glass rod with silk cloth, the glass rod becomes positively charged. The silk cloth becomes negatively charged. The electric charges generated by rubbing are static electric charges. These electric charges remain bound on the surface of the charged object.

The nature of charge on the other object will be positive. This is because like charges repel each other and unlike charges attract each other.

Parents – Father – I^A i – A group

Mother -I^A i – B group

Son – I^A I^A – AB group

Daughter – i i – O group

Father - Hb^A Hb^S, Mother - Hb^A Hb^S 

(Both Parents are heterozygous)

Answer is (b) 2n-1

Blood differs chemically from person to person. When two different incompatible blood types are mixed, agglutination (clumping together) of erythrocytes (RBC) occurs. The basis of these chemical differences is due to the presence of antigens (surface antigens) on the membrane of RBC and epithelial cells. Karl Landsteiner discovered two kinds of antigens called antigen ‘A’ and antigen ‘B’ on the surface of RBC’s of human blood. Based on the presence or absence of these antigens three kinds of blood groups, type ‘A’ , type ‘B’ , and type ‘O’ (universal donor) were recognized. The fourth and the rarest blood group ‘AB’ (universal recipient) was discovered in 1902 by two of Landsteiner’s students Von De Castelle and Sturli.

Bernstein in 1925 discovered that the inheritance of different blood groups in human beings is determined by a number of multiple allelic series. The three autosomal alleles located on chromosome 9 are concerned with the determination of blood group in any person. The gene controlling blood type has been labeled as ‘L’ (after the name of the discoverer, Landsteiner) or I (from isoagglutination). The I gene exists in three allelic forms, IA, IB and 1°. IA specifies A antigen. IB allele determines B antigen and 1°allele specifies no antigen. Individuals who possess these antigens in their fluids such as the saliva are called secretors.

Each allele (IA and IB) produces a transferase enzyme. IA allele produces N-acetyl galactose transferase and can add N-acetyl galactosamine (NAG) and IB allele encodes for the enzyme galactose transferase that adds galactose to the precursor (i.e. H substances). In the case of I^O /I^O allele no terminal transferase enzyme is produced and therefore called “null” allele and hence cannot add NAG or galactose to the precursor.

From the phenotypic combinations it is evident that the alleles I^A and I^B are dominant to 1° , but co-dominant to each other (I^A = I^B ). Their dominance hierarchy can be given as (I^A =I^B > 1^O ). A child receives one of three alleles from each parent, giving rise to six possible genotypes and four possible blood types (phenotypes). The genotypes are I^A I^A , I^A I^O , I^B I^B , I^B I^O , I^A I^B and I^O I^O.

Correct option is a) Multiple alleles

(d) Recessive trait carried by X-chromosome

(b) at same locus on homologous chromosome

When three or more alleles of a gene that control a particular trait occupy the same locus on the homologous chromosome of an organism, they are called multiple alleles and their inheritance is called multiple allelism.

(a) Multiple allelism

The rubber balloon becomes negatively charged when rubbed with a woolen cloth.

(B) becomes positively charged while cloth has a negative charge.

Father-I_A i or i i Mother-I_B or i i Son-i i

(b) hemophilia

(b) A, B and AB

Correct Answer is: (a) 1/4