Genetic Basis of Inheritance
Practice model questions for CBSe board exam and All types of medical entrance exams
Questions
A cross between yellow round and green wrinkled seed pea plants gave the following four types of progeny in equal proportions: yellow round, yellow wrinkled, green round and green wrinkled. The genotypes of the parents in this case must be
- YYRR X yyrr
- YyRr X yyrr
- YYRR X YYRR
- YyRr X YYRR
- yyrr X yyrr
Sickle cell anemia is caused by the presence of mutant alleles in the
- 10th chromosome
- 11th chromosome
- 12th chromosome
- 13th chromosome
Mendal conducted experiments in pea plant pisum sativum. The total number of chromosomes in pea plant is
- 4 pairs
- 5 pairs
- 7 pairs
- 14 pairs
Mendel's findings were rediscoverd in the year 1900 by
- Jacob and Monad
- De Vries, Corren and Tscherm
- Avery, MacLeod and McCarty
- Watson and Crick
Genetic constitution of an organism is called
- phenotype
- genotype
- dominant character
- co-dominance
In F2 generation of Mendel's monohybrid cross, recessive character appears in which of the following proportions?
- 1/2
- 1/4
- 2/4
- 3/4
Which of the following traits is a recessive feature studied by Mendel?
- Round seed
- Axial flower
- Violet flower
- Green seed
After a cross of round seeded plant with wrinkled seed plant, F1 produced 50 per cent round seed plants and 50 per cent wrinkled seed plants. What is the genotype of parental plants?
- RR X rr
- RR X RR
- Rr X RR
- Rr X rr
Which of the following is a sex-linked mendelian disorder?
- Sickle cell anemia
- Haemophilia
- Phenylketonuria
- Muscular dystrophy
Which of the following shows an incomplete dominance?
- Flower colour in Pisum sativum
- Flower colour in Mirabilis jalapa
- Flower colour in Lathyrus odoratus
- Eye colour in Drosophila melanogaster
The blood group of father is A and mother is AB. What is/are the possible blood group(s) of their children?
- A and AB
- A and B
- A,B and AB
- AB only
Gene mapping was first developed by
- T.H Morgan
- Alfred Staurtevant
- Alec Jeffrey
- De Vries
Which of the following characters is controlled by multiple allele?
- Flower colour in pea plant
- Flower colour in mirabilis
- Flower colour in snapdragon
- Blood group in man
A chromosomal abnormality in male due to trisomy of sex chromosome is
- Turner's syndrome
- Down's syndrome
- Klinefelter's syndrome
- Edward's syndrome
AB blood group in man is an example of
- complete dominance
- incomplete dominance
- codominance
- polygenic inheritance
ZW-ZZ type of sex determination is found in
- drosophila
- grasshopper
- humans
- birds
What will be the genotype(s) of F1 upon crossing 'TtRr' with 'ttrr'?
- TtRr
- TtRr and ttrr
- TtRr,Ttrr, ttRr, ttrr
- TTRR, ttRR, TTrr and ttrr
In epistatic type of inheritance
- the behaviour of two genes is entirely independent
- one gene alters the effect of the other
- a portion of a chromosome is deleted
- a portion of a chromosome is inverted
In the F2 generation of a dihybrid cross
- four phenotypes appear in the ratio 9 : 3 : 3 : 1, if the loci are linked
- four phenotypes appear in the ratio 9 : 3 : 3 : 1, if the loci are unlinked
- two phenotypes appear in the ratio 3 : 1, if the loci are unlinked
- 3 phenotypes appear in the ratio 1 : 2 : 1, if the loci are unlinked
If there is a lot of distance between two genes, the chance of crossing over
- is more
- is less
- is zero
- will remain unaffected
The experimental material of TH Morgan was
- pisum sativum
- drosophila melanogaster
- oenothera lamarckiana
- mirabilis jalapa
A cross between F1 and homozygous recessive parental combination is called
- back cross
- test cross
- reverse cross
- reciprocal cross
The percentage of 'ab' gametes produced by AaBb parent will be
- 25
- 50
- 75
- 80
If a haemophilic man marries a woman with haemophilia, what would be the possibility of their daughter being haemophilic?
- 100%
- 75%
- 50%
- 0%
In sickle cell anaemia due to point mutation, the sixth amino acid, glutamic acid in beta chain of haemoglobin is replaced by
- alanine
- tyrosine
- valine
- serine
- lysine