Dominant and Recessive Traits_Unsolved Paper
Chapter: Heredity and Evolution | Topic: Dominant and Recessive Traits
DOMINANT AND RECESSIVE TRAITS_UNSOLVED PAPER
Topic: Dominant and Recessive Traits
Q1. A trait that expresses itself in the presence of its contrasting allele is called:
- Recessive trait
- Dominant trait
- Acquired trait
- Environmental trait
Q2.If T represents the dominant allele for tallness and t represents the recessive allele for dwarfness, which genotype can show the dominant phenotype?
- TT only
- Tt only
- TT and Tt
- tt only
Q2. Which genotype represents a homozygous recessive condition?
- TT
- Tt
- Tt
- TTT
Q4. In a heterozygous individual, the recessive allele:
- Is absent
- Is always destroyed
- May remain unexpressed in the phenotype
- Changes into a dominant allele
Q5.If R is dominant over r, which genotype represents a heterozygous individual?
- RR
- Rr
- rr
- RRR
Q6. Which statement best describes a recessive trait?
- It always appears in every generation
- It can be expressed when the corresponding dominant allele is absent
- It cannot be inherited
- It is always an acquired characteristic
Short questions
Q1.Define a dominant trait and a recessive trait in the context of Mendelian inheritance.
Q2.What is the difference between a homozygous dominant and a heterozygous genotype?
Q3.Using T for tallness and t for dwarfness, write the genotypes for:
a) Homozygous tall
b) Heterozygous tall
c) Homozygous dwarf
Q4.Why can a recessive trait be present in an individual without being visible in the individual's phenotype?
Q5. A student observes a tall pea plant but does not know whether it has genotype TT or Tt.
Why cannot the phenotype alone always tell the student which of these two genotypes the plant has?
Q6.Two siblings inherit different combinations of alleles from their parents. One inherited trait is visible in one sibling but not in the other.
How can different allele combinations explain such differences?
Q1. Explain the difference between dominant and recessive traits using Mendel's pea-plant experiments. Include suitable examples of genotypes and phenotypes in your answer.
Q2. Consider the cross Tt × Tt, where T represents the dominant allele for tallness and t represents the recessive allele for dwarfness. Explain the possible genotypes and phenotypes that may occur among the offspring.
Q3. Explain why a recessive trait can disappear in one generation and reappear in a later generation. Use the concepts of alleles, dominant traits, recessive traits, and inheritance in your explanation.
Q1. In a cross Tt × Tt, assume T is dominant over t.
a) What fraction of the offspring is expected to have the homozygous recessive genotype?
b) What percentage does this fraction represent?
Q2. A student studies 100 pea plants obtained from a hypothetical cross and records:
a) What is the observed ratio of tall to dwarf plants?
b) Which phenotype represents the recessive trait if tallness is dominant?
Q3. A biology teacher gives a class two sets of allele cards:
A = dominant allele
a = recessive allele