quick biology concept class 12

important terms: aneupliody: its the condition in which a cell has  more or fewer number of chromosomes than the normal diploid number (46) types of aneuploidy 1.hyperploidy its a type of aneuploidy where the  total number of chromosomes is greater than normal. for eg. down syndrome(47),klinefelter syndrome(47),edward syndrome(47). 2.hypoploidy: its a type of aneuploidy where the total number of chromosomes is less than normal for eg.turner syndrome (45) causes of aneuploidy: during the cell division of anaphase stage there is a non dis junction  and chromosome are fail to seprate properly . types of human genetic disorder  there are two types of genetic disorder 1. mendelian disorder   2. chromosomal disorder . 1.mendelian disorder:    its determine by mutation of single gene . this disease also known as gene related disorder  they are transmitted to offspring as per mendelian principal  can be studied through pedigree analysis 2.chromo...

origin and evolution of man

pollination: its a transfer of pollen grain from anther to stigma of pistil called pollination    both male female are non motile  gamete have to brought together being fertilization kinds of pollination: on the basis of source of pollination  there are three types of pollination 1. autogamy 2.geitonogamy 3.xenogamy  autogamy: transfer of pollen grain from anther to stigma same flower of plant. geitonogamy: its shown in monocious plant. transfer of pollen from anther of one flower to stigma of another flower but in same plant. functionolly its cross pollination but mot a true cross pollination  xenogamy; in diocious plant   . transfer of pollen from anther of one plant to stigma of another flower of diffrent plant . .in this pollination  polliagent required. its a true cross pollination  variation ocour due to genetically . agents of pollination: there are two types of agents required for pollination  biotic [most common] abiotic[ra...