Anas Zoology

Taxonomical categories/ranks represents the group of organisms sharing common characteristics/features. Example: Insects represents a group of organisms sharing common features like three pair of jointed legs. Taxonomical categories include Kingdom, Phylum (for animals) and Division (for plants), Class, Order, Family, Genus and Species. Kingdom is the highest taxonomical category and species is the lowest taxonomical category. To place an organism in a particular taxonomical category one must have a knowledge of the organisms characteristics.  Taxonomical Categories: 1) Kingdom: It is the highest taxonomical category. There are 5 Kingdoms: Animal, Plants, Fungi, Protista and Monera Different organisms are placed in different kingdoms based on their characteristics. Example: a) Organisms that are multicellular, do not possess chlorophyll, cell wall is absent in cell, and are eukaryotic are placed in the Kingdom Animalia. e.g. Human, fishes, frog etc. b) Organisms that are multicellular

 It is the most accepted model of Plasma Membrane/Cell Membrane. It was proposed by Singer and Nicolson in the year 1972. Phospholipids form bilayer in the centre. their unsaturated fatty acids forms the tail and glycerol forms the head, which prevents the close packing of the molecules. Phospholipids show two types of movements: Transition and Flip-Flop movement. Transition: Molecules change their position in the same layer. Flip-Flop: Molecules interchange between two layers. There are two types of proteins in cell membrane/plasma membrane Extrinsic/Peripheral proteins - Form 30% of the total membrane protein, superficial, easily removed, some are covered by glycolipids/glycoproteins. They provide structural and functional specificity to the membrane. eg. ATPase, spectrin, acetycholinesterase etc. Intrinsic/Integral Proteins - Form 70% of the total membrane proteins, embedded in lipid bilayer, can be extracted by rupturing membrane, held in position by polar and nonpolar side of phos

A) Danielli - Davson Model / Sandwich Model / P-L-P Model: This model of plasma membrane was proposed by Danielli and Davson in the year 1935. According to this the plasma membrane is trilaminar, where lipids bilayer is sandwitched between the two protein layers. Hence it is also called as P-L-P model (P=protein, L=lipid). This model fails to explain functional specificity and active transport through membranes. B) Unit Membrane Model / Robertson Model: This model of plasma membrane was proposed by Robertson in the year 1959. According to Robertson, all membranes have the same basic structure but they have their own distinctive composition. Example: Internal organelles have more proteins than lipids in eukaryotic cells whereas plants and bacteria have more lipids than proteins. This model fails to explain the membranes stability and permeability. Related Articles: 1) Biomembranes https://anaszoology.blogspot.com/2022/08/biomembranes.html

Tricolour Pied Flat ( Coladenia indrani ) Clicked at Nagla Block, Mumbai. The Tricolour Pied Flat is a butterfly belonging to the family Hesperiidae.  Distribution: Found in Sri Lanka, India, Myanmar. Identification: The upperside of the butterfly is bright golden-yellow forewing with a discal series of four semi-transparent white black-bordered spots, the first small and above the extremity of the cell, the second large quadrate and within the cell, the third elongate and beneath the latter, the fourth exterior to their juncture Underside blackish-brown suffused with golden-yellow, brightest on the hindwing: markings as above but more clearly defined. Importance of Butterflies: Butterflies act as pollinators. When they feed on nectar of the flowers their bodies collect the pollens from these flowers. These pollens are then carried to other plants which helps to produce new seeds. Majority of the plants in nature needs pollinators like butterflies to reproduce. Butterflies helps to ma

Biomembrane/Biological Membrane is a semipermeable covering around the cell and organelles, which separated them from the external environment. Biomembrane which covers the cell is called a cell membrane/Plasmalemma, biomembrane which covers the organelle is called subcellular membrane. Composition of Biomembrane Biomembranes are tripartite or trilaminar i.e. made up of three layers Proteins : 59-75% fibrous or globular proteins Lipids : 20-40 % Phospholipid, sterol, glycolipid, sphingolipid Carbohydrates : 1-5% Hexose, hexamine, sialic acid Functions of Biomembranes: Helps to transport the solutes across the membrane. Biomembrane only allow certain types of molecules to enter the cell and organelle, they keep the toxins from entering into the cell. The receptors present on biomembranes helps the cells to communicate.

  An important tool of molecular biology is DNA fingerprinting. It is a way to distinguish individuals as it is unique for every living being (except clones) and cannot be altered by any process. Applications of DNA Fingerprinting: Paternity Test - The DNA fingerprint of child is matched with the prints of parents to determine family relationships. In parental disputes this technique is used to determine the true parents of the child. Criminal identification - DNA fingerprint from blood/hair/semen of suspect is picked up from the scene of crime, prepared and compared with the sample collected from scene. Many cases have been solved by this technique. Study Evolution - It is helpful in finding out genetic relationship between different races of man. Related Articles: DNA Fingerprinting:  https://anaszoology.blogspot.com/2022/08/dna-fingerprinting.html

An important tool of molecular biology is DNA fingerprinting. It is a way to distinguish individuals as it is unique for every living being (except clones) and cannot be altered by any process. All segments of DNA do not code for protein. Some segments have regulatory function, others are Introns (Interviewing sequence/IVS) still others are repetitive DNA sequences/Mini satellite sequences . The most important segment for DNA fingerprinting are short repetitive nucleotide sequences which vary from person to person. These are also called Variable number tendem repeats (VNTR). To prepare a DNA fingerprint a small amount of saliva/blood/hair/semen or any other cell of the body is required. Steps of DNA fingerprinting are as follows: Extract the DNA from the sample. If DNA is not sufficient, amplify it using PCR i.e. make more copies of DNA using PCR. Cut DNA with restriction endonucleases. The cut segments possess DNA of different length in different individuals called restriction length