Meritnation|Mar 15th, 2012 12:21pm
Genetics is one of the most difficult but interesting subjects in biology. A good understanding of genetics requires knowledge about the structure and function of cell, cell division and reproduction. Here are a few tips on how to master this subject.
|Marks||Chapter 5||Chapter 6||Chapter 7|
|Q. No.||Pg. No||Q.No||Pg. No||Q.No||Pg.No||2009 Set 1|
|1||1||130||2009 Set 2|
|1||3||111||2||130||2009 Set 3|
|1||4||112||6||127||2010 Set 3|
|1||7||112||2011 Set 1|
|1||7||112||2011 Set 3|
|Cross||Phenotypic Ratio||Genotypic Ratio|
|Let us now understand the cross involved,
XHXh x XhY
Gametes: XH, Xh and Xh, YPunnett Square: The gametes of the parents are taken on the horizontal and the vertical columns, here is the Punnett square for the given cross.
Therefore, the probability that the male child will be affected is 25% while 50% of their total progeny would be affected.In case of a dihybrid cross:
Questions on Pedigree Analysis:
|2009 Set 1(Delhi Region): Question 24
Haemophilia is a sex-linked recessive disorder of humans. The pedigree chart given below shows the inheritance of haemophilia in one’s family. Study the pattern of inheritance and answer the question given.
(a)Give all the possible genotypes of the members 4, 5 and 6 in the pedigree chart.
(b)A blood test shows that the individual 14 is a carrier of haemophilia. The member numbered 15 has recently married the member numbered 14. What is the probability that their first child will be a haemophilic male?
(a) 4 − Carrier female with genotype X*X
5 − Affected male with genotype X*Y
6 − Normal male with genotype XY
Here, X* represents the trait for haemophilia.
(bThere is a 25% probability that their first child will be a haemophilic male.
|Chapter / Marks
||1||2||3 and 5|
|Principles of Inheritance
|Laws of Mendel||Codominance|
|Test cross||Incomplete dominance|
|Sex Determination, Male and female Heterogamety|
|Mendelian and chromosomal disorders|
|Molecular Basis of Inheritance||Genetic code – start and stop codons||
Hershey and Chase Experiment
Messelson and Stahl
|histone proteins and
Modifications (capping, Tailing)
|Mutation||Features of the genetic code|
|Structure of tRNA|
|Goals and features of HGP|
|Evolution||Origin of life||Convergent and
|Natural selection and
|Natural selection and
|Human evolution||Hardy-Weinberg Principle|
Follow these simple tips to achieve great marks in the exam.
All the Best!