Anas Zoology

  Endoplasmic Reticulum (ER) Endoplasmic Reticulum (ER) is a system of sac like structures and tubes found in all eukaryotic cells. They are known as sarcoplasmic reticulum in skeletal muscles, Nissl granules in neurons and myeloid bodies in retinal pigment cells. They are absent in RBCs, eggs and embryonic cells. Endoplasmic Reticulum arise by evagination of nuclear membrane. Endoplasmic Reticulum have three parts: Cisternae: It is a sac like, parallel tubules having ribosomes on their surface. It is unbranched. Tubules: It is tube like, irregular, branched and without ribosome. Vesicles: They are round or spherical, without ribosomes Parts of Endoplasmic Reticulum . There are two types of endoplasmic reticulum  Rough Endoplasmic Reticulum (RER): They have ribosomes on their surface. The 60S unit of ribosomes are attached to the ER by means of a protein ribophorin I and ribophorin II. Number of cisternae and tubules are more. They are abundant near the nuclear membrane. They are

  Cytoplasm: Cytoplasm is the protoplasm present within the living cell, excluding nucleus. Cytoplasm is enclosed within cell membrane. Cytoplasm can be differentiated as: Cytoplasmic matrix / Cytosol / Hyaloplasm Cell inclusions Cell organelles Cytoplasmic Matrix: The Cytoplasmic matrix is the the gel like substance present in cytoplasm. It is more dense and viscous than the cytoplasmic fluid. Cytoplasmic matrix contains enzymes for synthesis of carbohydrates, fats, amino acids and proteins. Cell Inclusions: Cell inclusion are the non-living substances of cytoplasm. They may be in the form of reserve food, minerals, excretory and secretory products. Some of these are: 1) Starch grains: Exists as eccentric of concentric rings around proteinaceous hilum. It is stored in rhizomes, potato, rice, maize etc. Starch Grains around hilum 2) Fat droplets: They are present in animal cells in the form of adipocytes. Fat droplet in the cell 3) Glycogen granules: They are present in liver and muscl

Nucleus: Nucleus is a membrane enclosed organelle that contains the chromosome. It is present inside the cell. The study of nuclei of cells is known as Karyology. Nucleus is present in all cells except mature RBC's and sieve cells of xylem. The shape of nucleus varies. It can be oval, disc shaped, lobular, irregular etc In prokaryotes the nucleus is not covered by well defined membranes. In prokaryotes it is called as prokaryon/genophore/nucleoid. Normally a cell contains one nucleus but their number varies in certain cells e.g. binucleate liver cells and cartilage, polynucleate in osteoblast and skeletal muscles etc. Nucleus is made up of four parts: Nuclear Membrane Nucleoplasm/Karyoplasm Chromatin Network Nucleolus Different parts of Nucleus 1) Nuclear Membrane: It is a perforated double membrane. The pores have pore complex to regulate the size of pore. It seems to separate the contents of nucleus from cytoplasm. The nuclear membrane is made up of phospholipid bilayer. 2) Nucl

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

White-Eared Bulbul ( Pycnonotus leucotis ) The White-Eared Bulbul is a member of Pycnonotidae family. Distribution: It is found in south-western Asia from India to the Arabian Peninsula. Identification: It has a brownish-grey body. The tail is relatively long, starting off black and ending in white tips. The head is black, but the area around its cheeks is white. The vent is bright yellow. Conservation Status: Least Concern (LC) White-Eared Bulbul Realted Posts: Scarlet Skimmer:  https://anaszoology.blogspot.com/2022/08/scarlet-skimmer-blogpost-2.html

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/