XII: Chapter 5- Principles of inheritance and variations Flashcards
When did Mendel conduct his experiment on peas?
1856 to 1863 ( 7 years)
How many true breeding pea plant varieties did Mendel select?
14
What are the units of inheritance?
Genes
What does the I gene in ABO blood groups control?
The kind of sugar on the surface of RBC
Morgan crossed yellow bodied, white eyed male fruit flies with brown bodied, red eyed female fruit flies to get F1 generation. True/false?
False.
Morgan crossed yellow bodied, white eyed female fruit flies with brown bodied, red eyed male fruit flies to get F1 generation.
What percent of the offspring obtained in F2 generation were recombinants when yellow bodied, white eyed female fruit flies with brown bodied, red eyed male fruit flies were crossed?
1.3%
What percent of the offsprings obtained in F2 generation were recombinants when white and miniature wings were taken as characters in fruit flies?
37.2%
Phenylketonuria is caused by the mutation of which gene?
It is caused by mutation in gene that codes for enzyme phenyl alanine hydroxylase.
Who discovered X chromosome?
Henking
How many chromosomes does a female honeybee have?
32
What type of disorder is cystic fibrosis-Mendelian disorder or chromosomal disorder?
Mendelian disorder
Is myotonic dystrophy dominant or recessive? Is it sex linked?
Autosomal dominant
In colour blindness, defect is caused in
red or green cones of the eye
Why is sickle cell anaemia caused?
Substitution of glutamic acid by valine at the six position of the bets globulin chain of haemoglobin
Is phenylketonuria sex linked?
No
What happens due to the absence of phenyl alanine hydroxylase in phenyl ketonuria patient?
Phenylalanine is not converted into tyrosine, so phenylalanine is accumulated and converted to phenylpyruvic acid.
What causes thalassemia?
Mutation or deletion in gene which causes reduced rate of formation of α or β globin chains of haemoglobin.
α- Thalassemia is controlled by which genes?
Two closely linked genes HBA1 and HBA2 on chromosome 16 of each parent
α- Thalassemia can occur only because of mutation in one gene. True/false?
α- Thalassemia can occur because of mutation or deletion in one or more of the four genes (the genes being two closely linked genes HBA1 and HBA2 on chromosome 16 of each parent).
β- Thalassemia is controlled by which genes?
Single gene HBB on chromosome 11 of each parent
Down’s syndrome is caused due to
Trisomy of chromosome 21
Who coined the term genetics?
Bateson
What is the chemical basis of heredity?
DNA
What is the physical basis of heredity?
Gene
Who is called the father of modern genetics?
Bateson
Who is called the father of experimental genetics?
Morgan
In the experiment conducted by August Weisman, the tails of mice were cut for how many generations?
21 generations
The gene for flower colour in pea is located on which chromosome?
1
The gene for seed colour in pea is located on which chromosome?
1
The gene for plant height in pea is located on which chromosome?
4
The gene for flower position in pea is located on which chromosome?
4
The gene for pod shape in pea is located on which chromosome?
4
The gene for pod colour in pea is located on which chromosome?
5
The gene for seed shape in pea is located on which chromosome?
7
Which law would have Mendel discovered he had known that the 7 chosen characters in pea were present on 4 chromosomes?
Linkage
Who formulated Mendel’s generalisations into laws of inheritance?
Carl Correns
How many postulates were given by Mendel?
4
What is hemizygous condition?
Haploid condition
If there are n heterozygous allelic pair, then what will be the number of gametes?
2^n
Which of the Mendel’s laws has no exceptions?
Law of segregation
1:2:1:2:4:2:1:2:1 is the ratio of which property of a dihybrid cross?
Genotypic ratio
Mendel’s first law is
Law of segregation
Mendel’s second law is
Law of independent assortment
What is the phenotypic ratio of a trihybrid cross?
27:9:9:9:3:3:3:1
What is the cross in which sexes of parents are reversed as compared to other cross called?
Reciprocal cross
What is the cross in which a hybrid is crossed with its parent called?
Back cross
Crossing a hybrid with its dominant parent is called
Out cross
What is the relation between genotypic and phenotypic ratios in a test cross?
Genotypic and phenotypic ratios are the same
Who discovered incomplete dominance?
Carl Correns
What deviation from Mendelian crosses is observed in the flower colour in Mirabilis jalapa?
Incomplete dominance
What deviation from Mendelian crosses is observed in the plumage colour of Andulasian fowl?
Incomplete dominance
What deviation from Mendelian crosses is observed in the coat colour of short horned cattle?
Co-dominance
What is the phenotypic and genotypic ratio in coat colour of short horned cattle?
1:2:1 in both (polygenic inheritance)
What is the relation between genotypic and phenotypic ratios in codominance?
Genotypic and phenotypic ratios are the same
What is lethality as observed in coat colour of german mice?
Homozygous dominant mice (golden coat colour)die
What is the relation between genotypic and phenotypic ratios in lethality?
Genotypic and phenotypic ratios are the same
Which medication is provided to mother to prevent erythroblastalis foetalis?
Rhogam
When is the first dose of rhogam provided to mother?
6th month
When is the second dose of rhogam (first booster) provided to mother?
7th month
When is the third dose of rhogam (second booster) provided to mother?
8th month
When is the fourth dose of rhogam (third booster) provided to mother?
72 hours after pregnancy
What is qualitative inheritance?
Monogenic inheritance- single dominant allel determines complete character
What is quantitative inheritance?
Polygenic inheritance
What deviation from Mendelian crosses do height and intelligence show in humans?
Polygenic inheritance
What deviation from Mendelian crosses does flower colour in sweet pea show?
Complimentary genes
What is the phenotypic ratio in F2 generation under the effect of complementary genes in sweet pea?
9:7 (purple is C and P allele are present in genotype or else white)
What is the phenotypic ratio in F2 generation under the effect of supplementary genes?
9:3:4
What is the phenomenon of masking the expression of a gene by another non-allelic gene called?
Epistasis
What is the gene which suppresses the other gene in epistasis called?
Epistatic gene
What is the gene which is suppressed by the other gene in epistasis called?
Hypostatic gene
What is dominant epistasis?
Dominant gene at one locus suppresses dominant gene at other locus.
What is recessive epitstasis?
Recessive gene suppresses the dominant gene at other locus
Fruit colour in summer squash is the example of which type of deviation from mendelian laws? What is its phenotypic ratio?
Dominant epistasis
12:3:1
Coat colour in mice can be the example of which type of epistasis? What is its phenotypic ratio?
Recessive epistasis
9:3:4
Secondary constriction 1 is found in which chromosomes?
Chromosome number 1, 13, 14, 21, 22, Y
Secondary constriction 2 is found in which chromosomes?
Chromosome number 1, 10, 13, 16 and Y
Allosomes are also known as
Sex chromosomes
Idiochromosomes are also known as
Sex chromosomes
What is the representation of chromosomes of a cell arranged in decreasing order of size called?
Idiogram
What does honey contain?
Nectar + secretions of sub-maxillary glands of honey bee
What is value of X/A in meta female fruit flies?
> 1
What is value of X/A in female fruit flies?
1
What is value of X/A in intersex fruit flies?
1/2 < X/A <1
What is value of X/A in male fruit flies?
1/2
What is value of X/A in meta male fruit flies?
<1/2
Who gave the term mutation?
Hugo deVries
What kind of genetic mutation is albinism?
Autosomal recessive
What kind of genetic mutation is tay-sachs disease?
Autosomal recessive
What kind of genetic mutation is Alkaptonuria?
Autosomal recessive
What kind of genetic mutation is polydactyly?
Autosomal dominant
What kind of genetic mutation is brachydactyly?
Autosomal dominant
What kind of genetic mutation is Huntington’s chorea?
Autosomal dominant
What kind of genetic mutation is responsible for being able to tast PCT?
Autosomal dominant
Is congenital night blindness autosomal or sex linked?
Sex linked
What is meant by chromosomal abberration?
Change in number or arrangement of genes of chromosome
What is the ploidy of wheat?
6n
What is hypoploidy?
The number of chromosomes decreases in an organism
What is the chromosomal number in nullisomy?
2n-2
What is the difference between double monosomy and nullisomy?
Nullisomy- two chromosomes of same type are deleted
Double monosomy- two chromosomes of different types are deleted (2n-a-b)
What is mixed aneuploidy?
2n-a+b (one chromosome deleted, one chromosome added)
Palmar crease is the symptom of which disease?
Down’s syndrome
Edward’s syndrome is caused due to
Trisomy of chromosome 18
Horse shoe shaped kidney is a symptom of
Edward’s syndrome
Patau’s syndrome occurs due to
Trisomy of chromosome 13
Cry-du-chat syndrome is caused due to
Deletion of shorter arm of chromosome 5
Moon like face and receding chin are symptoms of
Cry-du-chat syndrome
What is the sex of a person with Klinefelter’s syndrome?
Male
What is genetic compliment of Jacob’s syndrome?
44+ XYY
What is known as black urine disease?
Alkaptonuria
The gene for phenyl ketonuria is located on
Chromosome 12
Mutated gene in albinism is present on which chromsome?
Long arm of chr-11 or chr-15
Tay-sachs disease is caused due to the accumulation of
Sphingolipids
Gaucher’s disease is caused due to the accumulation of
Cerebroside
Which disease is known as Cooley’s anaemia?
Thalassemia
Cystic fibrosis is caused by mutation in a gene present on chromosome
7
What is achondroplasia?
Dwarfism
What is polydactyly?
Presence of extra fingers
THe mutated gene in Huntington’s chorea is located on
CHromosome 4
Haemophilia A is caused due to absence of which clotting factor in body?
Factor VIII- Anti-haemophilic factor A
Haemophilia B is caused due to the absence of which clotting factor in body?
Factor IX
What is red colour blindness called?
Protanopia
What is green colour blindness callled?
Deuteranopia
What is blue colour blindness called?
Triatonopia
What is non criss cross inheritance?
Transfer of traits through members of same sex
What is criss cross inheritance?
Transfer of traits through members of opposite sex
What is holandric inheritance?
Only males are affected
Cytoplasmic inheritance can occur through
Mitochondria and plastids
Inheritance of kappa particles in paramecium is an example of which type of inheritance?
Cytoplasmic inheritance
Who gave the term crossing over?
Morgan
What is frequency of recombination?
Number of recombinants
————————————- X 100
total number of offsprings
What can be the maximum value of recombinant frequency?
50%
What is a linkage group?
The set of all genes on a chromosome
What is the ploidy of a genome?
n (haploid set of chromosomes)
What is autopolyploidy?
Increase in genomic number of same genome
What is allopolyploidy?
Hybridisation between two species followed by doubling of chromosomes
What are gynandromorphs?
Half the body of organism is male and half female
What is a free martin?
Infertile female cattle with masculinized behaviour which originates by acquiring male component in uterus through male twin
