Inheritance

Question 3:In a type of cattle, white face and long horns are dominant traits as opposed to those with black face and short horns as shown in Photograph 1. A breeder plans to breed all white face and long horns cattle in his farm. Prior to that, he has to ensure that his bull and … Read more

Question 2:A man has normal eyesight whereas his wife is colour blind. XB is a dominant allele for normal eyesight whereas Xb is a recessive allele for colour blindness. What is the probability of their children having:(a) Colour blindness?(b) Normal eyesight but a carrier?Explain your answers using a schematic diagram. Answer:Schematic diagram for colour blindness … Read more

Question 1:Figure 1 shows a cross between two pea plants, X and Y. If:(a) State the phenotypes of parental plants X and Y.(b) Complete the gamete genotypes produced by each parent, and phenotypes in F1 generation in Figure 1.(c) Table 1 shows the genotypes of F2 generation after F1 was crossed with another F1 generation. The … Read more

Question 1:A woman has heterozygous B blood group and a man has heterozygous A blood group. If the couple has an unidentical twins, what are the chances of both children having A blood group? Explain the inheritance of blood group of this family by using a schematic diagram using appropriate symbols. Answer:The probability of one … Read more

Question 1:State the meaning of:(a) locus(b) allele Answer:(a) Locus: Specific location of a gene in a chromosome.(b) Allele: An alternative form of a gene for a specific trait that is located on the same locus of a pair of homologous chromosome. Question 2:Based on the figure below, explain the relationship between locus, gene and allele. … Read more

Question 1:Mendel performed cross between pea plants to study two characteristics, namely flower position and flower colour. Which type of inheritance is this? Answer:Dihybrid inheritance Question 2:The following table shows dihybrid cross between two pea plants.Which F1 generation phenotypes are probably produced? Answer:Round and yellow pod, round and green pod, constricted and yellow pod, constricted … Read more

Question 1:What is meant by purebreed? Answer:Purebreed means that the organism genotype is homozygous; whether it is homozygous dominant or homozygous recessive. The organism carries two similar alleles for each characteristic. Question 2:In a fertilisation between two rats, B represents dominant allele for black fur, whereas b represents recessive allele for white fur. If the … Read more

Activity 11.1:AimTo carry out an experiment using beads to illustrate monohybrid fertilisation by analogyApparatusTwo black plastic bags, 100 red beads, 100 white beadsAnalogyRed bead represents dominant allele for red-coloured flowers (R)White bead represents recessive allele for white-coloured flower (r)ProcedureFertilisation between two heterozygous or hybrid plants of first filial generation F1:1. Place 50 red beads and … Read more