Anas Zoology

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

 The organisms whose cells contain a membrane bound nucleus and membrane bound organelles are called a eukaryotes. Structure of Eukaryotic Cell Characteristics of Eukaryotic Cell: Cell size and volume depend on the activities performed by it (5 - 100 μm). Cellulosic cell wall is present only in plant cells. Capsule is absent. Mesosome is absent. Well organized nucleus is present. Mononucleate condition is more common. DNA is linear and is covered by histonic protein (except in mitochondria and plastid). Monocistronic DNA is more common. Three kinds of RNA polymerase are present. One for each - rRNA, mRNA, tRNA. Transcription occurs in the nucleus and translation in the cytoplasm. Extranuclear chromosome are absent. Ribosome is 80S (60S + 40S). Protein synthesis is inhibited by cyclohexamide. All organelles are present. Cilia and flagella show characteristic 9+2 arrangement of microtubule and are made up of protein tubulin. Microfilaments are present. True sap vacuoles are common in pla

A prokaryote is a single celled organism that lacks a true nucleus and other membrane bound organelles. Structure of Prokaryotic Cell Characteristics of Prokaryotic Cells:  Cell is small in size (0.1 - 5 micrometers). Cell wall is made up of muramic acid (amino acid derivative of peptidoglycan). In many cells mucopolysaccharide capsule is present. Mesosomes controls cellular respiration and cell division. An organised nucleus is absent. DNA is circular and naked. Usually polycistronic DNA is present. Only one kind of RNA polymerase is present. Transcription and translation both occurs in the cytoplasm. Extracellular chromosomes are present in the form of plasmid or episome. Ribosome id 70S (50S + 30S) Cytoplasm lack cell organelles. If flagella is present, it is made up of single stranded protein called flagellin. Microfilaments - Actin and myosin are absent. Sap vacuoles are absent instead they have gas vacuoles. Endocytosis and exocytosis are absent. They divide by amitosis or simple

  What is Mutualism ? It is a positive relationship between two individuals of species where both the species are benefited. Examples of Mutualism: Pollination by Animals: animals like bees. butterflies and moths derive their food from plants and brings about the pollination of plants. Ants feed on honeydew produced as a waste product by aphids and in return offer them protection. Oxpecker feeds on ticks and blood-sucking flies from the body of large grazing mammals like zebras, buffalos, rhinos etc. This helps the large mammals from getting infected by such parasites and in return oxpecker's gets an easy meal. Oxpecker and Buffalo (Image taken from: https://www.youtube.com/watch?v=5MfrsKJailo)

What is Commensalism ? Commensalism is a positive interaction and a symbiotic relationship between two species in which one species benefits and the other neither benefits nor is harmed. Three terms are used to describe different types of commensalism Inquilinism: When one species uses other species for shelter. Example: Woodpecker drilling a hole in cactus to use it as a nesting site. The cactus is unaffected while the woodpecker is benefited. Phoresy: Occurs when one organism uses a second organism for transportation. Example: The Bromeliad treefrog carry ostracods from one bromeliad plant to another. Metabiosis: Occurs when one organism uses something produced by the first, usually after its death. Example: Hermit crab using the shell of a dead gastropod for protection. Other examples of Commensalism: Vultures feeds on the leftovers of kills of carnivores and other dead animals. It is a type of commensalism since vultures benefits without affecting the dead animals. The fish remora