👉🏻   B.SC AGRICULTURE  👈🏻

  • 2018-19 objectives : 

  • Definitions : 

1. Chromosome mapping: is the assignment of genes to specific locations on a
chromosome. OR A technique used in autosomal DNA testing which allow to determine which segments of DNA came from which ancestor.

 2. Genotype: Genetic constitution of an individual,

3. Quantitative characters: Characters which are governed by several genes. 

4. Crossing over: Interchange of parts between non sister chromatids of homologous chromosome during pachytene.

5. Genetics: A biological science which deals with the principles of heredity and variation. Or Study of structure, composition and function of genes.

6. Multiple allele: Existance of more than two alleles at a locus

7. Dihybrid cross: A cross involving two pairs of gene, each affecting different characters.

8. Chi-square test: Test of statistical significance which is used to test the significance of difference between observed and expected frequencies or ratio.

  • Fill in the blanks.

1. Germplasm theory was proposed by August Weismann in 1889.

2.  Mitochondria is known as power house of cells. 2

3 Test cross is a cross of F, with homozygous recessive parents..

4 Mendel studied seven pairs of contrasting characters. 

5. Alternative form of gene is known as allele.

6. A cross involving one pair of gene affecting one character is known as monohybrid cross.

7. Masking effect of one allel over the other is known as Dominance.

8. Co-dominance is the expression of both the allels in a heterozygote or F₁.

  • 2017-18 objectives : 

  • Give the contribution of following scientists: 

1. Erwin Chargaff :
He demonstrated that adenine and thymine groups are equal to the guanine and cytosine.

2. Barbara McClintock :
She discovered the jumping genes in maize.

3. Seymour Benzer
He gave the sub divisions of genes.

4. Har Gobind Khorana
He discovered how the genetic components of the cell nucleus control the synthesis of protein.

5. Flemming
He discovered mitosis 

6. H. J. Muller
He showed that X-rays can speed up the natural process of mutation.

7. Hugo De Vries
He coined the term mutation

8. W. L. Johannsen
He coined the pureline

  • Define the following terms :

1. Allele
The alternative form of gene is called as allele.

2. Karyotype
Karyotype referes to the characteristic features of chromosomes of a species.

3. Homozygous
Individuals having similar alleles on the corresponding locus of homologous chroromosome is called as Homozygous

4. Heredity
The transfer of characters from one generation to other generation is called as Heredity. 

5. Mutation
Sudden hen table change in an individual is

6. Back cross
A cross between a F1 or hybrid and either of its patents 

7. Genotype
The entire genetic constitution of an organism

8. Crossing over
An exchange of corresponding segments between non-sister chromatids of homologus chromosome during pachytene prophase.

  • 2021-22 :

  • Define the following terms:

1) pleiotropy : 
When one gene influence / affect multiple phenotypic traits.

2) Karyokinesis:
Karyokinesis is the division of cell nucleus during mitosis.

3) Codominance :
A condition in which two dominant allels are expressed at the same time.

4) Lethal gene : 
Genes which causes the death of organism which carries them.
5) Allosomes :
Allosomes are the sex chromosomes that determines the sex of the individual also sex linked cHaracters of individual.

7) Phenotype : 
Phenotype is the external appearance of the individual.

 8) Mutagen : 
Mutagen is the any agent which causes mutation.

  • State True or False:

(1) A combination of deoxyribose sugar and nitrogenous base in known as nucleoside.
Ans. True

2) Crossing over takes place during zygotene stage of meiosis.
Ans. False

3) Polygenes are also called as major genes.

4) The recessive character is expressed in F1 generation.
Ans.  False

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