Biology 11 & 12 Supplementary Study Material

SUPPLEMENTARY MATERIAL FOR

SENIOR SECONDARY BIOLOGY

National Curriculum for 2012 (Class XI & XII) has been revised under the aegis of COBSE in consensus with NCERT and CBSE.

Genetics Facts

GENETICS FACTS

• Father of Genetics Gregor John Mendel.

• Hugo deVries, Carl Correns & Tschermak independently rediscovered Mendelism.

• Theory of Continuity of Germplasm proposed by Weismann.

• Chromosomal Theory of Inheritance proposed by Sutton & Boveri.

• De-novo synthesis of biologically active DNA done by Itakure.

• Gene Term coined by Johanssen (1905).

• Genetics, Genotype & phenotype terms coined by Bateson.

• Spontaneous Mutations were discovered by Hugo de Vries.

• Linkage in Drosophila studied by Thomas Hunt Morgan.

• Evidence of Semiconservative replication found by Meselson & Stahl. 

• Double Helix of DNA described by James Watson & Francis Crick.

• One gene one peptide hypothesis given by Beadle & Tatum.

• Lac Operon  in E. coli Studied by Jacob and Monod.

• Gene for bobbed brostles discovered by Curt Stern.

• Jumping genes or Transposomes discovered by Barbra McClinton.

• Triplet Codon proposed by Gamow.

• Experimental evidence of triplet codon given by Nirenberg and  Mathaei.

• Polymerase Chain Reaction (PCR) discover by Kary Mullis.

• DNA Fingerprinting discovered by Alec Jeffrey.

• Di-deoxy Method of Nucleotide sequencing discovered by Fredric Sanger.

• Method of sequencing of Amino acids in a polypeptide was also discovered by Sanger. 

• Father of Eugenics is Francis Galton.

• Chiasma discovered by Jenssens.

• Experimental proof of Nucleus responsible for heredity given by Hammerling.

• Proof of DNA as genetic material from Transduction Experiment by Harshey & Chase.

• Wobble hypothesis proposed by Francis Crick.

• Inborn errors in metabolism of human being discovered by Achibald Garrod.

• Terms Heterochromatin and Euchromatin proposed by Heitz. 

•  Experiments of Nuclear Transplantation by Robert Briggs & Thomas King.

• Naturalistic or Biochemical Origin of  life proposed by Operin.

• Oncogenes discovered by Michael Bishop & Harol Vermus (1976).

Microbiology Facts

MICROBIOLOGY FACTS

• Virus discovered by Ivanowsky.

• Amoeba discovered by Rosenhof (1755).

• T M V crystallised by Stanley.

• dsRNA present in Wound Tumor Virus, Rice Dwarf Virus, Rheovirus.

• ssDNA present in psi x 174 Virus.

• Conjugation in bacteria discovered by Lederberg & Tatum.

• Transduction in bacteria discovered by Lederberg & Zinder.

• Transformation in bacteria discovered by Griffith (1928).

• Theory of Spontaneous generation proposed by Louis Pasteur.

• Group of bacteria raised to the level of Division by Bold & Tippo.

• Pure culture of bacteria first time obtained by Joseph Lister.

• Discovered and isolated Streptomycin by Waksman ( 1944-45).

• Tuberculosis germs discovered by Robert Koch.

• First Vaccine against Small pox prepared by Edward Jenner.

• Term antibiotic first used by Waksman.

• First Antibiotic Penicillin discovered by Alexander Fleming.

• Heterothallism in fungi (Rhizopus) discovered by Blakeslee.

• Apospory discovered by Druery.

• Apogamy discovered by Farlow.

• Apospory named by De Bary.

• Term alternation of generation first used by Hofmeister.

Cell Biology - Basic Facts

CYTOLOGY FACTS

• Robert Hooke discovered and coined term CELL.
• Robert Brown (1831)  discovered Nucleus.
• Fontana (1781) discovered Nucleolus. 
• Bowman (1840) coined term Nucleolus.
• Dumortier (1832) first of all studied Mitosis.
• Purkinje (1839) & Von Mohl (1840) named protoplasm.
• Schleiden & Schwann (18H39) proposed Cell Theory.
• Rudolf Virchow (1855) generalised  "Omnis Cellilae cellula".
• Kolliker (1862)  used term Cytoplasm.
• E. Haeckel (1866) coined term Plastid.
• Schimper (1883) studied chloroplast.
• Kolliker (1880) observed Mitochondria.
• Benda (1897) Named Mitochondria.
• George (1867) saw Golgi Apparatus.
• Camillo Golgi ( 1898) studied Golgi Body.
• Hofmeister (1848) observed Chromosomes.
• Waldeyer (1888) Named Chromosomes.
• Strasburger (1873) told that new nuclei are formed from old nucleus.
• Flemming ( 1880) used term mitosis.
• Fol ( 1893) discovered Spindle and Asters.
• Strasburger(1888) worked out detail of Meiosis.
• Farmer and Moore (1905) named Meiosis.

• His (1870) formed Microtome.
• Svedberg ( 1926) discovered Ultra Centrifuge.
• Knoll and Ruska (1932) discovered Electron Microscope.
• Zernicke (1935-40) developed Phase Contrast Microscope.
• Talbot ( 1834) discovered Polarising Microscope.
• Coons(1945) discovered Fluorescent Microscope.

• Robertson ( 1959) discovered cell membrane.
• Porter & Thompson (1945) discovered E.R.
• Robinson & Brown (1953) discovered Ribosomes.
• de Duve (1953) discovered Lysosomes.
• Robertis & Franchi ( 1953) discovered Microtubules.

Bio XI Branches of Biology

Branches of Biology

Aerobiology – the study of airborne organic particles

Agriculture – the study of producing crops from the land, with an emphasis on practical applications

Anatomy – the study of form and function, in plants, animals, and other organisms, or specifically in humans

Arachnology – the study of arachnids

Astrobiology – the study of evolution, distribution, and future of life in the universe—also known as exobiology, exopaleontology, and bioastronomy

Biochemistry – the study of the chemical reactions required for life to exist and function, usually a focus on the cellular level

Bioengineering – the study of biology through the means of engineering with an emphasis on applied knowledge and especially related to biotechnology

Biogeography – the study of the distribution of species spatially and temporally

Bioinformatics – the use of information technology for the study, collection, and storage of genomic and other biological data

Biomathematics (or Mathematical biology) – the quantitative or mathematical study of biological processes, with an emphasis on modeling

Biomechanics – often considered a branch of medicine, the study of the mechanics of living beings, with an emphasis on applied use through prosthetics or orthotics

Biomedical research – the study of the human body in health and disease

Biophysics – the study of biological processes through physics, by applying the theories and methods traditionally used in the physical sciences

Biotechnology – a new and sometimes controversial branch of biology that studies the manipulation of living matter, including genetic modification and synthetic biology

Building biology – the study of the indoor living environment

Botany – the study of plants

Cell biology – the study of the cell as a complete unit, and the molecular and chemical interactions that occur within a living cell

Conservation biology – the study of the preservation, protection, or restoration of the natural environment, natural ecosystems, vegetation, and wildlife

Cryobiology – the study of the effects of lower than normally preferred temperatures on living beings

Developmental biology – the study of the processes through which an organism forms, from zygote to full structure

Ecology – the study of the interactions of living organisms with one another and with the non-living elements of their environment

Embryology – the study of the development of embryo (from fecundation to birth)

Entomology – the study of insects

Environmental biology – the study of the natural world, as a whole or in a particular area, especially as affected by human activity

Epidemiology – a major component of public health research, studying factors affecting the health of populations

Epigenetics – the study of heritable changes in gene expression or cellular phenotype caused by mechanisms other than changes in the underlying DNA sequence

Ethology – the study of animal behavior

Evolutionary biology – the study of the origin and descent of species over time

Genetics – the study of genes and heredity

Herpetology – the study of reptiles and amphibians

Histology – the study of cells and tissues, a microscopic branch of anatomy

Ichthyology – the study of fish

Integrative biology – the study of whole organisms

Limnology – the study of inland waters

Mammalogy – the study of mammals

Marine biology (or Biological oceanography) – the study of ocean ecosystems, plants, animals, and other living beings

Microbiology – the study of microscopic organisms (microorganisms) and their interactions with other living things

Molecular biology – the study of biology and biological functions at the molecular level, some cross over with biochemistry

Mycology – the study of fungi

Neurobiology – the study of the nervous system, including anatomy, physiology and pathology

Oncology – the study of cancer processes, including virus or mutation oncogenesis, angiogenesis and tissues remoldings

Ornithology – the study of birds

Population biology – the study of groups of conspecific organisms, including

Population ecology – the study of how population dynamics and extinction

Population genetics – the study of changes in gene frequencies in populations of organisms

Paleontology – the study of fossils and sometimes geographic evidence of prehistoric life

Pathobiology or pathology – the study of diseases, and the causes, processes, nature, and development of disease

Parasitology – the study of parasites and parasitism

Pharmacology – the study and practical application of preparation, use, and effects of drugs and synthetic medicines

Physiology – the study of the functioning of living organisms and the organs and parts of living organisms

Phytopathology – the study of plant diseases (also called Plant Pathology)

Psychobiology – the study of the biological bases of psychology

Sociobiology – the study of the biological bases of sociology

Structural biology – a branch of molecular biology, biochemistry, and biophysics concerned with the molecular structure of biological macromolecules

Virology – the study of viruses and some other virus-like agents

Zoology – the study of animals, including classification, physiology, development, and behavior (branches include: Entomology, Ethology, Herpetology, Ichthyology, Mammalogy, and Ornithology)

Bio XII Terms of Mendelian Genetics

Terms to know in Mendelian Genetics

Mendel's law of dominance
There is always a pair of factors ( genes, alleles) which controls each character in an individual. One whose expression is observed in hybrid is dominant while another is recessive.

Mendel's law of segregation
Alleles segregate from one another during the formation of gametes.

Mendel's law of independent assortment of alleles.
Alleles of different genes are assorted independently of one another during the formation of gametes.

alleles
The different forms of a gene. Y and y are different alleles of the gene that determines seed color. Alleles occupy the same locus, or position, on chromosomes.

Autosomal
A locus on any chromosome but a sex chromosome. Not sex-linked.

Co-dominant alleles
Both alleles express their phenotypic effect when present in a heterozygote. For example, the alleles A and B are said to be co-dominant in case of human blood groups.

Complete linkage.
Complete linkage describes the inheritance patterns for 2 genes on the same chromosome when their is no crossing over.

Dioecious
Unisexual; Organisms produce only one type of gamete; i.e. humans

Dominant trait.
A trait expressed preferentially over another trait.

Drosophila melanogaster
The fruit fly, a favorite organism for genetic analysis.

Epistasis.
One gene masks the expression of a different gene for a different trait.

F1 generation
Offspring of a cross between true breeding plants, homozygous for the trait of interest

F2 generation
Offspring of a cross involving the F1 generation.

Genotype
The genetic makeup of an organism with respect to a trait. For a single trait either YY or Yy.

Hemizygous
If there is only one copy of a gene for a particular trait In a diploid organism, the organism is hemizygous for the trait, and will display a recessive phenotype. X-linked genes in fly or human males are hemizygous.

Heterozygous
Differing alleles for a trait in an individual, such as Yy.

Homologous chromosomes
The pair of chromosomes in a diploid individual that have the same overall genetic content. One member of each homologous pair of chromosomes in inherited from each parent.

Homozygous
Both alleles for a trait are the same in an individual. They can be homozygous dominant (YY), or homozygous recessive (yy).

Hybrid
heterozygous; usually referring to the offspring of two true-breeding (homozygous) individuals differing in the traits of interest.

Incomplete dominance
Intermediate phenotype in F1, parental phenotypes reappear in F2. The flowers of the snapdragon plant can be red, pink, or white. Color is determined at a single locus. The genotype RR results in red flowers and rr results in white flowers. The heterozygote genotype of Rr results in pink flowers. When the heterozygote has a different, intermediate phenotype compared to the homozygous dominant or homozygous recessive individuals, this is said to be incomplete dominance.

Lethal alleles.
Mutated genes that are capable of causing death.

Linkage.
genes that are inherited together on the same chromosome. Three inheritance patterns are possible: non-linkage, Partial linkage, and complete linkage.

Monoecious
Bisexual; Organisms produce both male and female gametes; i.e. garden pea.

Monohybrid cross.
Cross involving study of only one character.

Mutation
Sudden change in the DNA sequence of a gene to some new, heritable form. Generally, but now always a recessive allele.

Phenotype
The physical appearance of an organism with respect to a trait, i.e. yellow (Y) or green (y) seeds in garden peas. The dominant trait is normally represented with a capital letter, and the recessive trait with the same lower case letter.

Recessive trait.
The opposite of dominant. A trait that is preferentially masked.

Reciprocal cross
Using male and female gametes for two different traits, alternating the source of gametes.

Sex chromosomes
Sex determination is based on sex chromosomes

Sex-linked.
A gene coded on a sex chromosome, such as the X-chromosome linked genes of flies and man.

Back cross
Cross of an offspring with any of the parent.

Test cross
Generally a cross involving a homozygous recessive individual. When a single trait is being studies, a test cross is a cross between an individual with the dominant phenotype but of unknown genotype (homozygous or heterozygous) with a homozygous recessive individual. If the unknown is heterozygous, then approximately 50% of the offspring should display the recessive phenotype.