Genetics and Plant breeding Pointers 1

 

• Genetics is the study of gene operation and heredity from parents to offspring.
• The term genetics was coined by W. Bateson in 1905.
• Gregor John Mendel is known as the 'father of modern genetics.'
• The cell is recognized as the functional unit of life.
• The cell was discovered by R. Hooke in 1665.
• The cell theory was proposed by M.J. Schleiden and T.  Schwann in 1939.
• Protoplasm is known as the physical basis of life.
• There are two types of cells found in the living world: eukaryotic and prokaryotic.
• A plant cell is classified as a eukaryotic cell.
• Ribosomes are the cell organelles found in both prokaryotic and eukaryotic cells.
• Cells without a cell wall are called protoplasts.
• The nucleus serves as the controlling center of the cell.
• The nucleus was discovered by Robert Brown in 1831.
• The organelle known as the “powerhouse of the cell” is the mitochondria.
• Mitochondria were discovered by Hollicker.
• The term mitochondria was coined by Benda in 1897.
• The term endoplasmic reticulum was introduced by Porter in 1948.
• The organelle known as the engine of the cell is the ribosome.
• Rough ER is associated with ribosomes.
• The main site of protein synthesis is the ribosome.
• 70S ribosomes are found in mitochondria.
• The prokaryotic organism that does not contain mitochondria is bacteria.
• The term lysosome was first used by Dave in 1955.
• The organelle known as the suicidal bag of the cell is the lysosome.
• The main function of the Golgi body is the packing and transport of food materials.
• The organelle known as the dustbin of the cell is the vacuole.
• The non-living organelle of the cell is the cell wall.
• The material contained in vacuoles is called cell sap.
• Plastids are self-replicating, extra-chromosomal genetic materials found in plant cells.
• The term plastids was introduced by Lederberg.
• The organelles found only in plants are plastids and spherosomes.
• The plastid responsible for photosynthesis in plants is the chloroplast.
• The plastid responsible for color in plants is the chromoplast.
• The plastid that stores starch and fat in plants is the leucoplast.
• The leucoplast that functions as the storage of oil is called lipoplast.
• Thread-like bodies that carry genes are called chromosomes.
• Strasburger was the first to discover chromosomes in 1875.
• The term chromosome was coined by Waldeyer in 1888.
• The chromosomal theory of inheritance was proposed by Sutton and Boveri.
• The fundamental unit of a chromosome is chromatin.
• The part of the chromosome known as primary constriction is called the centromere.
• The major genetic constituent of a chromosome is DNA.
• One cycle of mitosis produces two daughter cells.
• The term mitosis was coined by Walter Flemming in 1882.
• Mitosis occurs in somatic cells.
• The longest phase of mitosis is prophase.
• The shortest phase of mitosis is anaphase.
• The middle stage of mitosis, where chromosomes are arranged at the equatorial plate, is called metaphase.
• The stage of DNA synthesis in mitosis occurs during interphase.
• One cycle of meiosis produces four daughter cells.
• The term meiosis was first given by J.B. Farmer in 1905.
• Meiosis occurs in reproductive cells.
• Crossing over and recombination occur during meiosis division.
• The pachytene stage is when crossing over takes place.
• Chiasmata occurs during the diplotene stage.
• Spindle formation takes place during metaphase I.
• The process of separation of chromatids is called disjunction.
• Mendel was born on July 22, 1822.
• Mendel worked on the seven contrasting characters of the garden pea.
• The rediscovery of Mendel’s work was done by Hugo de Vries, Erich Correns, and Erich Tschermak in 1900.
• The accepted theory of Mendel is the Law of Segregation.
• A Mendelian population is also known as a random mating population.
• A tall pea plant (DD) and a tall pea plant (Dd) share the same phenotype.
• The double helix model of DNA was proposed by Watson and Crick in 1953.
• The process of using information from DNA to construct mRNA is called transcription.
• The transfer of genetic material from mRNA to protein is known as translation.
• An expression of one gene depends on the presence or absence of another gene, known as epistasis or gene interaction.
• The phenotypic ratio of a monohybrid cross is 3:1.
• The phenotypic ratio of a dihybrid cross is 9:3:3:1.
• The triplet sequence found in mRNA that codes for a single amino acid is called a codon.
• The triplet sequence in tRNA is known as an anticodon.
• 5 inbred lines will lead to 10 single crosses.
• The term genomics was coined by Thomas Roderick in 1986.
• The concept of pangenesis was developed by Darwin.
• The theory of evolution through natural selection was proposed by C. Darwin and A.R. Wallace in 1858.
• The theory of acquired characteristics was developed by Lamarck.
• The chromosomal theory of heredity was proposed by W. Sutton in 1902.
• Genes for sex-linked traits are located on the Y chromosome.
• Humans have 23 pairs of homologous chromosomes.