Anas Zoology

  Eukaryotic Cell Eukaryotic Cell The cells which contain true nuclei are called eukaryotic cells. Eukaryotic cells are found in animals, plants, algae and fungi. They are larger in size as compared to prokaryotic cells. The cells may vary in shape, size and physiology but they all have a typical structure with little variations in number and location of cellular organelles. The eukaryotic cell have a outer covering membrane called plasma membrane / cell membrane. Inside the cell a membrane-bound nucleus is present. Between the nucleus and plasma membrane, cytoplasm is present in which various cellular organelles like mitochondria, golgi complex, centrioles etc can be seen. ✱ Shape: Eukaryotic cells exhibit diversity. They can be spherical, triangular, tubular, cuboidal, polygonal, cylindrical, oval, rounded or elongated. Shape of cells may vary from organ to organ. A single organ may show variations in shape of cell. ✱ Size: Eukaryotic cells are microscopic. They are larger in size

  (Image Source:  https://pmgbiology.files.wordpress.com/2015/10/chromosomes.jpg?w=300 ) Chromosomes are found inside the nucleus of the cell. The number of chromosomes differ from organism to organism. Humans have 23 pairs i.e. 46 chromosomes. Out of these 23 pairs, 22 pairs are autosomes and 1 pair is of sex chromosomes. Human female have XX as the sex chromosome and human male have XY as the sex chromosome. One set (23 chromosome) is inherited from the maternal (female parent) and another set from the paternal (male parent). Since two sets are present inside the cell, the cell is called as diploid (di=two, ploid=set). All somatic cells of the body are diploid. Gametes (sperm and ovum) contains only one set of chromosomes and hence are called haploid. The number of chromosomes in each somatic cell is the same for all members of a given species.  Chromosome Morphology: (Image Source:  https://microbiologynotes.org/wp-content/uploads/2020/07/types-of-Telomere.jpg ) Chromosomes can be d

  Golgi Complex / Golgi Apparatus Golgi apparatus is found in all types of eukaryotic cells except the mammalian RBCs. It is absent in prokaryotes. Golgi apparatus are small sacs which are responsible for transporting, modifying and packaging proteins and lipids. The golgi apparatus was discovered by Camillo Golgi in 1898. He discovered them in the nerve cells. Golgi apparatus has a system of outer flattened cisternae which appears as parallel membranes in the form of an ellipse.  There are two faces known as cis and trans face of golgi apparatus. The cis face lies near the rough endoplasmic reticulum and the trans face lies near to the cell membrane. Substances from the rough endoplasmic reticulum enter through the cis face for processing and they exit from the trans face in the form of smaller vesicles. Functions: Packaging center of cell. Proteins are processed and sorted for their transport. Lipid processing. Secretory proteins like hormones are packed into secretory vesicles for t

The specialized structures seen inside the living cells are called cell organelles. Different cell organelles present inside a cell are: Nucleus Ribosomes Endoplasmic Reticulum (Smooth and Rough) Cytoskeleton Golgi complex/apparatus Mitochondria Lysosomes Centriole Vacuoles

What are Lipids? A lipid is a class of organic compound which is a fatty acid or its derivative. They are insoluble in water but soluble in organic solvent. Major lipids in cell membrane are: Phospholipids  Cholesterol 1) Phospholipids: The lipid substances containing phosphorous and fatty acids are called phospholipids. There are different types of phospholipids present in cell membrane, they are as follows: Aminophospholipids Phosphatidylinositol Sphingomyelin Phosphatidylserine Phosphatidylcholine Phosphatidylglycerol Phosphatidylethanolamine The phospholipid molecules are arranged in two layers in cell membrane. A phospholipid molecule consist of two parts: head portion and tail portion. The head portion is made up of phosphate group and a glycerol atom and tail portion is made up of two fatty acid chains. Head portion is polar and hydrophilic (Strong affinity for water). The tail portion is non polar and hydrophobic (repelled by water/water fearing). Structure of Phospholipid The

What is DNA Barcoding? It is a technique use to identify animals, plants and microbes. A short section of DNA from a gene is used to identify the species. The short section of DNA which is used is called DNA Barcode. Dr. Paul D.N. Hebert is the founder of DNA barcoding. The gene region which is used for animal groups is Cytochrome- C oxidase I gene abbreviated as CO-1. Procedure: Take the tissue from the specimen to extract the DNA. Isolate the barcode region. Multiply the isolated DNA using PCR. Then it is sequenced The sequence obtained is placed in BOLD database (Barcode of Life Data system). It is a reference library of DNA barcodes which can be used to identify unknown specimens. Advantages: Useful in identifying species where morphological techniques are not enough. Provide evidence in poaching cases.   Related Articles: DNA Fingerprinting:  https://anaszoology.blogspot.com/2022/08/dna-fingerprinting.html Applications of DNA Fingerprinting:  https://anaszoology.blogspot.com/2022/

Amino acids are compounds containing carbon, hydrogen, oxygen and nitrogen. They serve as monomers of proteins. Amino acids contains an amino group, a carboxyl group, a hydrogen atom and a distinctive side chain, all these are bonded to the same carbon atom, this carbon atom is called as ∝-carbon. The amino acids differ with respect to the side chain attached to their ∝-carbon. General structure of Amino Acid This general structure is common to all amino acids except for one i.e. proline. The side chain attached to the ∝-carbon atom is different for each amino acid. In ∝-amino acids the amino group and the carboxyl group are attached to the same carbon atom. Amino acids can be classified as β Ɣ δ or ε based on the location of carbon atom to which the amino group is attached.

  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