Heredity and Evolution Part – II – Sex Determination|Class 10 Science Notes
Heredity and Evolution Part – II – Sex Determination|Class 10 Science Notes We have already discussed the previous article on Chapter – 9
What are Heredity and Evolution? from class 10 science, but in this article, we will discuss the topic of Sex Determination. Factors considered determining Sex 1 Environmental Fact In some animals, the temperature at which eggs are fertilized determined the gender. 2 Genetic In some animals class 10 science Heredity and evolution Part II Sex chromosome In human beings, there are 23 pairs of chromosome. Out of these 22 chromosome pairs are called autosomes and the last pair of the chromosome that help in deciding the gender of that individual is called the sex chromosome.
Heredity and Evolution Part – II – Sex Determination|Class 10 Science Notes XX- Female chromosome
XY- Male chromosome The human gender can be determined by the pair of the chromosome called a sex chromosome. Check another notes on NCERT Class 10 Science What is Family Planning and Birth Control? Evolution It is the sequence of gradual changes taking place in the primitive organism, over millions of years in which new species are produced. Acquired Trait These are traits which are developed in an individual due to special conditions. It cannot be transferred to the progeny and it cannot divert evolution. Eg low weight of starving beetles.
Heredity and Evolution Part – II – Sex Determination|Class 10 Science Notes Inherited traits These are traits which are passed from one generation to the next. It gets transferred to progeny and it helps in evolution. Eg color of eyes and hair. Speciation ways Gene flow It occurs between a population that is partly but nor completely separated. Genetic drift It is the random change in the frequency of alleles in a population over successive generations. Natural selection The process by which nature selects and consolidates that organism which is more suitable adapted and possesses favorable variations. Geographical isolation It is caused by mountain ranges, rivers etc.
Heredity and Evolution Part – II – Sex Determination|Class 10 Science Notes Evolution and classification Evolution and classification are interlinks Classification of species is the reflection of their evolutionary relationship. The more characteristics two species have in common the more closely they are related. The more closely they are related, the more recently they have a common sensor. Similarities among organisms allow us to group them together and to study their characteristics.
Heredity and Evolution Part – II – Sex Determination|Class 10 Science Notes Make your learning interesting and longlasting with animated learning videos for 10th Class Science , register with us to know more. Evidence of evolution Homogenous organs These are organs that have basic structural plan and origin but different functions. Example winds of the bat, the paw of a cat Analogous organ These are organs that have different origin and structural plan but same function. Example- wings of bat have elongated fingers with skin folds. Get NCERT Solutions of Heredity and Evolution of Class 10 Science Click here to know more. Preparing for Board Exams and want to score highe