problem1) Fill in the blanks:

(i) Failure of two homologous chromosomes to separate normally during cell division is known as..............

(ii) The occurrence of introns was discovered in the organism...............

(iii) If F1 is crossed with its recessive parent, then this cross will be known as.............

(iv) Crossing over takes place during............stage of Prophase I.

(v) The ability of a plant cell to develop into a complete new plant is called.............

2. State whether the following statements are true or false.

(i) A person having AB blood group is called as universal recipient.

(ii) Sexual reproduction causes genetic variability in offspring.

(iii) A cross between a homozygous tall pea plant and a heterozygous tall pea plant will produce 100% tall pea plants.

(iv) Alternative name for trisomic;18 is Edward Syndrome.

(v) Hormones regulate transcription in eukaryotes.

problem3) Match the items given in Column I with those given in Column II.

Column I                                           Column II
(i) Mosaics                                    (a) Transposons
(ii) Mobile genetic elements             (b) Cell mediated immunity
(iii) Phenylketonuria                        (c) Dispermic fertilisation
(iv) Lymphocytes                           (d) Vector
(v) Plasmid                                    (e) Pleiotropic trait

problem4) Name the technique used for:

(i) Studying chromosome morphology

(ii) Prenatal diagnosis of genetic disorders in humans

(iii) Observation of DNA regions in chloroplast

(iv) Regeneration of plants from excised tissues of mature plants

(v) Analysis of DNA structure

problem5) Indicate the year and the name the scientist(s) who discovered the following:

(i) Rh Factor

(ii) Conjugation in bacteria

(iii) Jumping genes

(iv) Z-DNA

(v) Mutations

problem6) Give the ex each for the following:

(i) Criss;cross inheritance

(ii) Sex-limited traits

(iii) Phenotypic expression of holandric inheritance

(iv) ZZ-ZW system of sex determination

(v) Constitutive gene

problem7) Two red flowered plants A and B when crossed with a white flowered plant C gave the following results:

(i) Red (A) x White (C)→ All Red flowered plants

(ii) Red (B) x White (C)→ 1 Red flowered plant: 1 White flowered plant. Describe the reasons for the difference in the results of the two crosses and prepare the genotypes of the parents and the progeny.

problem8) Two persons with blood groups O and AB are in need of blood transfusion. Blood of which group can be given to each of them? Describe the reasons.