(i) Two animals which have nineteen pairs of chromosomes.(ii) The type of gene which in the presence of a contrasting allele is not expressed.(iii) The branch of science dealing with heredity.(iv) A hereditary disease in which blood does not clot.(v) The unit of heredity.(vi) The number of pairs of autosomes in human being.(vii) The condition of both the alleles being identical.(viii) The chemical substance constituting genes.(ix) The sex chromosome of male.(x) The allele which expresses itself on the other.(xi) The genetic make up of an organism.(xii) A cross between one pair of contrasting character.(xiii) Two sex linked inherited diseases.Solution:(i) Cat and sheep.(ii) Recessive genes.(iii) Genetics.(iv) Haemophilia.(v) Genes.(vi) 22 pairs.(vii) Homozygous.(viii) DNA.(i) ! and ".() Dominant.(i) Genotype.(ii) #onohy$rid cross.(iii) Haemophilia % Colour &lindness.uestion .!. State whether the following are true or false :(i) The chemical present in gene is "#A.(ii) $oth the identical allele are called homo%ygous.(iii) The genetic make up of an organism is called phenotype.(iv) Two arms of a chromosome is called centromere.(v) The plant used by &endel was sweet pea.Solution:(i) '(ii) ((iii) '(iv) '(v) '.uestion .'. (efine by giving an example :(i) Allele.(ii) )henotype.(iii) *omo%ygous.(iv) *eredity.CloseClose(v) +enetics(vi) Trait.uestion .,. -n a certain species of animals black fur ($) is dominant over brown fur (b). )redict a genotype and phenotype of the offsprings when both parents are $b or have hetero%ygous black fur.uestion ... (ifferentiate the following :(i) +enotype and )henotype.(ii) Autosomes and Sex chromosomes.Answer : Clic) Hereuestion ./. Answer the following 0uestion :(i) State &endel1s law of dominance.(ii) 2hat is a dihybrid ratio 3(iii) 2hat are autosomes 3(iv) 2hat is gene 3(v) 2hat is genetic disease 3 #ame two genetic diseases.(vi) 2hat is (#A 3(vii) 4xplain how the sex of a child depends upon its father.(viii) 2hy did &endel select garden pea for his experiments 3