Biology
HEREDITY
1- Mendel (Father of genetics) experiments stands for Heredity.
2-Differences in characters with in closely related groups of organisms are called variations.
Externally visible characters are called phenotype.
3-TT or YY, Tt or Yy are responsible for a dominant character.
4-There are nearly 180 vestigial (not useful) organs in man (moving museum of vestigial organs).
Ex. Pinna, hair on skin, appendix
5-The process of acquiring change is called evolution.
6-The allosomes (sex chromosomes) present in female are XX and in males are XY.
7-The phenotypic ratio in monohybrid cross is 3:1, and genotypic ratio is 1:2:1.
8-Evolution of man: 1. Homo habilus 2. Homo erectus 3. Homo sapiens neanderthalensis 3.Homo sapiens(present man).
9-The study of fossils (evidence of ancient life forms) is called palaeontology.
10-Mendel had chosen 7 pairs of characteristics for his study in pea plants.
11-Phenotypic ratio in di hybrid cross is 9:3:3:1.
12-Alleles are same for character in homologous and different in heterologous.
13-Paleontologists determine the age of fossils by carbon dating.
14-Change in frequency of genes in small population is known as genetic drift.
15-Transmission of characters from parent to offspring is called heredity and the process is called inheritance.
16-Each human cell contains 22 (autosomes) + 1 (allosomes) pairs of chromosomes.
17-Variations are formed during sexual reproduction or because of errors in DNA copying.
18-Augustus Weismann proved in rats that the body changes won’t be passed to its offspring.
19-Mendel factors are now known as genes (segment of DNA).
20-The law of inheritance of acquired characters was proposed by Lamarck.
21-Evolution of new species is called speciation (macro evolution).
22-Charles Lyell wrote the book “The principals of geology”.
23-Theory of natural selection was proposed by Darwin.
24-Evolution of homologous traits is called divergent and heterologous is convergent evolution.