Inheritance1. Define CharacterCharacter is a distinctive inherited feature of an organism2. Differentiate between character and traitCharacter is the distinctive inherited feature of an organism. On the other hand, trait is the different variations of a character. For example, tall and short stems are the traits for the character height in a plant.3. What are the character and traits in that were chosen by Mendel for his experiments?CharacterTraits

Stem LengthTallShort

Flower colourPurple White

Flower positionAxial Terminal

Pod (fruit) shapeInflatedConstricted

Pod colourGreenYellow

Seed shapeRound Wrinkled

Seed colourYellowGreen

4. What is an allele?It is one of the alternative form of a gene. In a diploid cell there are usually two alleles occupying the same locus of a homologous chromosome.5. What is a gene?A gene is a hereditary unit composed of DNA. It is a basic unit of inheritance that determines a particular characteristic in an organism.6. Which plant did Mendel choose for his genetic experiments?Mendel choose Pisum sativum or the pea plant for his experiment.7. Give reasons for Mendels choice of plant.Mendel chooses the pea plant because the species comes with a lot of variations in its characteristics. For example, different heights, different flower colours, different shapes of the pods and so on. Such vast variation in the characters offered him more material for genetic research. Pea plant grow rapidly and thus, it was easier for him to study quite a few generations in a short span of time and make his observations. Pea plants can also be grown very easily and does not need much tending to or special care.8. What is a dominant trait?A dominant trait is the one that is expressed in an organism, suppressing the recessive trait9. What is a recessive trait?A recessive trait is one that stays suppressed or cannot be expressed in the presence of the dominant trait. For example, in the pea plant, the dominant trait is tall and the recessive trait is short or dwarf.10. What is a dominant allele?It is an allele that carries the dominant trait and is expressed in the phenotype of the organism. The dominant trait (tall) is represented by T or T is the dominant allele.11. What is recessive allele?It is an allele that carries the recessive trait and is only expressed as the phenotype of the organism in the absence of the dominant allele. The recessive trait (short or dwarf) is represented by t or t is the recessive allele.12. What is a genotypeGenotype is the genetic constituent of an organism. That is, the different alleles of different traits present in a gene. For example, TT, Tt and tt.13. What is phenotypePhenotype is the observable characteristics of an organism which is determined by the specific genotype. That is whether the plant is tall, short, with white flowers or red ones etc.

14. What are homozygous alleles?Alleles that form the allelic pair are the same. An individual that contains only one allele at the allelic pair is known as homozygote. For example, TT is homozygous dominant and tt is homozygous recessive; pure lines are homozygous for the gene of interest.15. What are heterozygous alleles?Alleles that form the allelic pair are different. An individual that contains one of each member of the gene pair is known as heterozygote. For example, Tt is heterozygous.16. What are pure breeding plants?Pure breeding plants are those which when self-fertilized, produce identical offspring generation after generation.17. What is test cross?Test cross is a way to identify the genotypes of an individual to see whether it is homozygous or heterozygous for a dominant character. This is done by crossing an individual which exhibits the homozygous recessive genotype with the individual for which the test cross is being done.18. What is a monohybrid cross?It is a genetic cross done between parents that differ in the alleles they possess for one particular gene. One parent having two dominant alleles and the other having two recessive.19. State the importance of meiosis I in the segregation of alleles.The segregation of anaphase I of meiosis explain Mendels observation that each parent gives on allele for each trait at random to each offspring, regardless of whether the allele is expressed or not. Factors or genes for different traits are inherited independently of each other.

20. What is a dihybrid cross?It is a genetic cross between parents that differ in two characters controlled by genes at different loci.21. State the importance of meiosis in terms of independent assortment of chromosomes.

22. Write a note of the ABO system of blood group determination.23. What is Rhesus factor?24. When are the anti-Rhesus antibodies stimulated?25. What is a karyotype?26. What are chromosomes?27. What are autosomes? How many autosomes are there in a human cell?28. What causes Downs syndrome?29. How is sex in humans determinated?30. What are sex-lined inheritances? And Explain sex-linked inheritance of haemophilia31. What are hereditary diseases? And Describe thalassaemia