UPSC CIVIL SERVICES RESULT 2015-2016

IMPORTANT TERMS OF GENETICS-GENERAL SCIENCE FOR IAS


       Principles of inheritance and variation





This is the most important topic in genetics (biology) .In this topic you will learn and understand some important terms of inheritance science (inheritance biology) such as process of inheritance .


Principle of inheritance and variation –It is fifth chapter of NCERT/CBSE BOOK CLASS 12(Twelve).Students find inheritance biology little hard ,so we presented this topic in a simple manner hope it will help you.
KNOWLEDGE BOOSTER-FROM CLASS 12 BIOLOGY

GENERAL SCIENCE-BIOLOGY NCERT/CBSE NOTES(CLASS12 FOR IAS) 

ENVIRONMENTAL ISSUES–GENERAL SCIENCE NOTES FOR IAS 

HUMAN HEALTH AND DISEASE

 ECOLOGY-ECOSYSTEM

 SEXUAL REPRODUCTION IN FLOWERING PLANTS













This topic is also important for civil services preliminary exam(general science) and mains too .We have already posted some other important topics from class 12 biology(NCERT/CBSE) and other classes which is useful for civil services exam(IAS) in General science.




Genetics                                                                                              

Genetics is the branch of science that deals with inheritance and variation of characters.

Heredity                                                                                              

Heredity is defined as the process of transmission of characters from one generation to the next.

Variation                                                                                             

Variation refers to the character differences among the individuals of a species.

Offspring                                                                                            

An offspring is an individual produced by sexual reproduction.

Alleles                                                                                                 

The various of slightly different forms of a gene, are called alleles.

Phenotype                                                                                           

The observable or external characteristics of an organisms,constitute it’s phenotype.

Genotype                                                                                             

The genetic constitution of an organisms is called it’s genotype.

Homozygote/Pure breeding                                                              

It is an individual organisms in which the members of a pair of alleles for the character are similar.

Heterozygote/Hybrid                                                                         

It is an individual organisms in which the members of a pair of alleles for the character are dissimilar or different.

Dominant Factor/Alleles                                                                   

Dominant allele is the allele which expresses itself in a hybrid,where the members of a pair of alleles for the character are different.

Recessive allele                                                                                   

It is a allele which is suppressed (or does not express itself )in the hybrid,where the members of a pair of alleles for the character are different.

Dominant Character                                                                         

The form of the hybrid character/trait which is expressed in the hybrid ,is called the dominant character.

Recessive Character                                                                           

The form of the character /trait which is suppressed (hidden) in the hybrid,is called the recessive character.

Monohybrid cross                                                                              

It is a cross made between two individuals of a species, considering the inheritance of the contrasting pair of a single character /trait.

Monohybrid                                                                                       

It is the individual that is heterozygous for the alleles (of a gene) controlling one character.

Dihybrid cross                                                                                    

It is a cross made between individuals of a species, considering the inheritance of contrasting pair of two traits.

Dihybrid                                                                                             

It is the individual that is heterozygous for the alleles(of two genes)controlling two characters/traits.

Emasculation                                                                                      

It is the process of removal of anther from a bisexual flower,before the pollen grains mature.

Incomplete dominance                                                                  

When neither of the two alleles of a gene is completely dominant over the other, the phenomenon is called incomplete dominance.

Codominance                                                                                     

When two alleles of a gene are equally dominant and express themselves in the presence of other (when they are together )the phenomenon is called codominance.

Multiple Allelism                                                                               

When a gene exist in more than two allelic forms the phenomenon is called multiple allelism.

Pleiotropy                                                                                                                      

Pleiotropy is defined as the ability of a gene to have more than one phenotypic effect.

Punnet Square                                                                                    

Punnet square is a device that has been created to yield a diagram that allows an easy representation of hybridization data.

Link genes                                                                                           

All the genes present on a chromosome,are called linked genes.

Linkage                                                                                                

Linkage is the phenomenon ,where two or more linked genes are always inherited together and their recombination frequency in a test cross is less than 50%

Non-disjunction                                                                                

Non-disjunction is the phenomenon in which the members of a homologous pair of chromosomes do not separate during meiosis.

Aneuploidy                                                                                         

Aneuploidy is the phenomenon of gain or loss of one or more chromosomes that results due to failure of separation of the members of the homologous pair(s) of chromosomes during meiosis.

Monosomy                                                                                          

Monosomy is the condition where a particular chromosome is present in a single copy,in a diploid cell/nucleus.

Trisomy                                                                                               

Trisomy is the condition where  a particular chromosome is present in three copies in a diploid cell/nucleus.

Male Heterogamety                                                                           

Male heterogamety is the phenomenon where the males produce two different types of gametes/sperms.

Female Heterogamety                                                                        

Female Heterogamety is the phenomenon where the females produce two different types of gamets or ova.

Autosomes                                                                                          

All those chromosomes of an individual organism,that are not involved in the determinationof sex of that individual are called autosomes.

Sex-chromosomes                                                                             

The chromosomes of an individual organism,that are involved in the determination of sex of that individual ,are called sex-chromosomes.

Mutation                                                                                             

Mutation is defined as the sudden,heritable change in the base sequence of DNA or structure of chromosome or change ion the number of chromosomes.

Pedigree analysis                                                                               

It is an analysis of the distribution and movement of traits in a series of generation of a family.

                                        Print Friendly and PDF

Print Friendly and PDF

No comments:

Civilservicesias.com Posting Guidelines

We offer users the ability to comment on news items and also engage in discussions in our message board
The following types of posts may be deleted:

1.Use of offensive racial / gender /religion-bashing terms or other hurtful speech.
2.Spam and links to spam.We may remove hyperlinks within comments.
3.Personal attacks on other posters.Comment on ideas, not people.