Rajasthan Board Class 10 Science Chapter 3 Solution Genetics RBSE Class 10 Science Solution for Chapter 3
Objective Type of Questions
(1.) Who coined the term genetics-
(2.) Experiments of mendel were on-
a) Sweet pea
b) Wild pea
c) Garden pea
d) All of above
(3.) Study of heredity and variation is alled-
d) None of the above
Ans- a) genetis
(4.) Green colour of pea pod is which type of character-
c) Incomplete dominance
(5.) Usually number of alleles of gene are
(6.) Mendel selected how many pairs of constracting characters for his experiment-
(7.) When F1 generation is crossed with any one parent, then it is called as-
a) Reciprocal cross
b) Test cross
c) Back cross
d) All of the above
Ans-c) back cross
(8.) Ratio of offsprings from Tt tt cross is
(9.) Which constracting character was not selected by mendel for his experiments-
a) Colour of root
b) Colour of flower
c) Colour of seed
d) Colour of pod
Ans-a) clour of root
(10.) How many types of genotypes fromed in F2 generation of monohydried cross-
Ans – d)9
Very Short type questions.
(11.) Who is called father of genetics?
Ans- mendel is a called father of genetics.
(12.) Which plant was selected by mendel for his experiments?
Ans- pisum sativum (garden pea)
(13.) What is dominant character?
Ans-the character which express itself as f1 generation is called dominant characters.
(14.) what is knows as the transmission of genetic characters from one generation to another generation?
(15.) Who rediscoverd mendel’s laws?
Ans-The Hungo De Vries, Carl Corrnes and Erich von Tschermak rediscoverd the laws of mendel.
(16.) what is the full name of mendel?
Ans- Gregor Johan Mendel
(17.) write the name of laws proposed by mendel.
Ans-1.law of dominance, 2. Law of segregation or law of purity of gamets 3. Law of independent assortment
(18.) What is test cross?
Ans- if F1 generation (Tt) is crossed with recessive parent (tt) then it is called as test cross.
(19.) What do you understand by out cross.
Ans-the out crossed shows the offspring obtained 50%homogeneous and 50%heterogeneous.
(20.) Which laws of mendel can not be explained by monohybrid cross?
Ans-law of independence assortment.
Short type questions.
(21.) Write the difference between phenotype and genotype.
Ans – difference between phonotype and genotype as follow:-
External appearance of an individual is called phenotype eg. Tall plant which genotypically may be homozygous (TT)or heterozygous(Tt). Genetic constitution of an individual is called genotype. Eg. Pure or homozygous tall(TT) or heterozygous tall (Tt).
(22.) Explain the dihybride cross.
Ans- dihybrid cross is a such type of cross in which two constrasting characters (traits) is considered is called dihybrid cross. The dihybrid cross for phenotypic ratio is 9:3:3:1 and genotypic ratio is 1:2:2:4:1:2:1:2:1.
(25.) Write a brief life introduction of the Mendel.
Gregor Johann Mendel is called father of genetics because mendel prposed the laws of inheritance in plants for the first time. Mendel was born on 22th july 1822 in silision village of heinzendarf state of Austria. Mendel perfom hybridization experiments on garden pea for seven years. Mendel proposed the law iof inheritance which are also known as Mendelism mendel died on junuary 6, 1884.
(26.) Explain the mendel’s law of dominace.
Ans- this laws depend on the results of mendels monohybrid cross. According to this law, when a cross takes place in between homozygous constracting plants the character wich express itself in F1 generation is called Dominace and the character which is not express itself on F1 generation are called recessive.
(27.) Write the importance of menedel’s laws of inheritance.
Ans- A) It is important to find dominant character in living organisms because many harmful and lethal recessive genes are not able to express themselves in the presence of dominant gene.
B) Gene concept was proved by mendel’s law of segregation.
C) According to law of segregation one gene has tow alleles and they control two contrasting characters.
D) With the help of Mendel’s laws, we know about the new characters develop in hybrid off spring.
E) Useful characters can be brought into same species and harmful characters can be removed by the method of hybridization.
Easy type questions.
(28.) Explain the mendel’s law of segregation with example.
Ans- this law is also called as the Law of Purity. According to this law-during gamete formation from hybrid or heterozygous of F1 generation both alleles separates or segregate to each other, therefore , it is called as law of segregation and each gamete carries one allele for each character therefore it is also called as law of purity of gametes.
Example- if homozygous tall (TT) plant is crossed with homozygous dwarf(tt) plant then in F1 generation all plants were hybrid or heterozygous ta;; (Tt). Therefore phonotypic ratio is 3:1 and genotypic ratio is 1:2:3 this is called law of segregation.
(29.) What is mendelism? Explain law of independent assortment in detail.
Ans- mendel proposed the laws of inheritance which are also known as Mendelism.
The law of independent assortment- this law is based on result of mendel’s dihybrid cross. According to this law _if two or more than two constracting characters are consider then there is not any effect of inheritance of one character on the inheritance of another character or alels of each character are not only separate but allels of different characters behave independently or they assort independently, therefore, it is called law of independent assortment.
Example- if homozygous yellow round seeded (YYRR) plant is crossed with green wrinkled (yyrr) plant is crossed seeded(YyRr)
Then the phenotypic generation of F2 generation is 9:3:3:1 and genotypic ratio is 1:2:2:4:1:2:1:2:1.
(30.) Explain the Mendel’s laws of inheritance.
Ans- Mendel’s proposed some important laws through hybridization experiments on garden pea which are called Mendel’ laws of inheritance.
a) Law of dominance- this law is based on monohybrid cross. According to this law, when a cross takes place in between homozygous contrasting plants the character which express itself in F1 generation is called dominant character and which is not express it self is called recessive.
b) Law of segregation- this is also based on monohybrid cross. During gamets formation from hybrid or heterogeneous of F1 generation, both allels separates or segregates to each other, therefore it is called as law of segregation .phenotypic ratio is 3:1 and genotypic ratio is 1:2:3. It also have two types test cross and back cross.
c) The law of independent – if two or more contrasting characters are considered then there is not any effect of inheritance of one character on the inheritance of another or allels of each character of another character or allels of each character are not only separate but allels of different characters behave independently or they assort independently, therefore, it is called law of independent. the phenotypic ratio is 9:3:3:1 and phenotypic ratio is 1:2:2:4:1:2:1:2:1.
This are called is called laws of inheritance.