Answer : Recessive gene is not expressed in the presence of a contrasting dominant allele.
Answer : It is a type of cross which is performed by taking only one pair of contrasting character or one feature at a time.
Answer : During gamete formation, the alleles for each gene seggregate from each other so that each gamete carries only one allele for each gene.
Answer : a) 44 + XX-chromosome.
Answer : Mutation is the term used for a sudden heritable change in the gene.
Answer : Phenotype is the physical expression of genes in an individual.
Answer : b) Homozygous condition.
Answer : Gene is a portion (or sequence) of DNA that codes for a known cellular function or process. These are also called the unit of inheritance containing the information required to express a trait.
Answer : Allele is one of a number of alternative form of the same gene.
Answer : The difference between set, odd one and category are given below.
|Haemophilia, colour blindness, albinism, night blindness||Night blindness (it is caused due to nutritional deficiency)||Sex-linked diseases|
Answer : Suppressed allele of a gene pair is called recessive allele.
Answer : Phenotype is the observable characteristic which is generally controlled.
Answer : Phenotypic ratio in F2-generation of monohybrid cross is 3:1.
While, phenotypic ratio in F2-generation of dihybrid cross is 9 : 3 : 3 : 1
Answer : The statement is false. It can be correctly written as chromosomes other than the pair of sex-chromosomes are called autosomes.
|It is the genetic makeup of an organism.||It is the physical or observable characteristic of an organism.|
Answer : A pair of chromosomes carrying dissimilar alleles of a particular character is called heterozygous.
Answer : Colour blindness and haemophilia are the two sex-linked diseases in males.
Answer : The dihybrid ratio is 9 : 3 : 3 : 1
Based on the observation in dihybird crosses Mendel proposed Law of independent assortment (third law) which states that when two pairs of contrasting characters are combined in a hybrid, segregation of members of one pair of a gamete is independent of member of another pair of gamete.
Answer : The pair of genes responsible for a particular characteristics in an individual are called alleles.
Answer : The difference between pure strains and hybrid strains are given below:
|Pure strains||Hybrid strains|
|These are made up of some type of alleles.||These are made up of different types of alleles.|
Answer : Genotype is known as the genetic constitution of an organism.
Answer : This law states that when two alternative forms of trait or character are present in an organism, only one factor expressed itself in F1-progeny. This factor is called dominant factor, while the other factor which remains hidden is called recessive factor. It explains the expression of a gene in a cross and 3 : 1 ratio is obtained in F2-generation.
Answer : The ratio of each phenotype (or appearance) of the seeds in the F2-generation obtained in a dihybrid cross is called dihybrid ratio, i.e. 9 : 3 : 3 : 1.
Answer : Phenotype are the physical or observable characterisitics of an organism which are generally controlled.
Answer : A chromosome that is not an allosome, i.e. not sex chromosome is called an autosome. These are exactly similar chromosomes in both males and females (22 pairs).