NE ADVANCED BIOLOGY SERIES TANZANIA 2025/2026
NE SUPER SERIES FORM SIX JOINT EXAMINATION
GENETICS: SOLVING QUESTIONS FORM SIX HOMEPACKAGE DECEMBER 2025
5. In summer squash plants, the gene W for white fruits suppresses the expression of gene
Y for yellow fruits. Yellow colour is only expressed when the white gene is recessive (w).
Additionally, when the yellow gene is recessive (y), the fruits are green. Using this
information:
(a) Identify and define the inheritance pattern demonstrated in this cross.
(b) Interpret the relationship between the genes:
(i) White and yellow fruit colors
(ii) Yellow and green fruit colors
(c) Draw a table showing all possible genotypes and their corresponding fruit
phenotypes in this inheritance pattern.
(d) Perform a genetic cross between a pure-breeding white summer squash and a
purebreeding green summer squash.
(i) Show the genotypes and phenotypes of the F1 generation. Then, use the F1
offspring to determine the genotypes and phenotypes of the F2 generation.
(ii) Determine the phenotypic ratio observed in the F2 generation?
6. (a) Explain why farmers are not advised to plant hybrid seeds such as tomatoes from
one season to another.
(b) Explain the role and location of each type of the Ribonucleic Acid in a cell.
(c) After school study tour, a form six student observed a species of Guinea pig (caria
sp). There are two allele of hair colour, black and white allele and two alleles for hair
length, short and long. In breeding experiment all the F1 phenotype produced from
a cross between pure short black hair and pure breed, long white – haired parent,
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had short black hair and the F1 generation were allowed to breed to obtain F2
generation with the following results:
109 Short, black hair
100 Short, white hair
36 Long, black hair
29 Long and white hair
(i) Which kind of inheritance is this?
(ii) Show the F1 and F2 generation genotype and phenotype using Punnet
square. 7. (a) State Mendel's law of independent assortment.
(b) A researcher carried out a breeding experiment by crossing a pure long-stemmed
and purple-flowered pea plant with a pure short-white pea plant. In F1 all plants
were long stemmed purple-flowered pea plants. After selfing F2 generation gave four
phenotypes in the ratio of 9:3:3:1
(i) Illustrate how he arrived at this ratio.
(ii) What test will he carry to obtain the ratio of 1:1:1:1, illustrate the genetic test.
8. With the use of genetic crosses describe the mode of inheritance of haemophilia and
sickle cell anaemia.
9. (a) (i) Farmers are not advised to plant hybrid seeds such as tomatoes from one season
to another, why.
(ii) All hereditary materials are genetic materials, but not all, genetic materials are
hereditary materials. Comment on that statement.
(b) Maua is a form six, Student with blood type A, she recently had a baby with blood
type O, whose father she insisted was a fellow student called Kasheshe, Kasheshe
refused out right. This paternity case was taken to court, where the following facts
were established.
(i) Kasheshe’s mother was blood group A
(ii) Kasheshe’s father was blood type
Would the law accuse or excuse Kasheshe? Use symbolized diagram to show how
you reach your conclusion.

MATOKEO YA MITIHANI KIDATO CHA PILI 2025
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