সহজ কথায় Egg (ডিম বা ডিম্ব) বলতে প্রাণীর নিষিক্ত ডিম্বাণু তথা নিষিক্ত স্ত্রী প্রজনন কোষকে বোঝায় যেখানে ভ্রুণ বিকাশমান বা পরিস্ফুটনরত (developing) অবস্থায় থাকে। ডিম নিষিক্ত হওয়ায় এর ক্রোমোজম সংখ্যা ডিপ্লয়েড (Diploid) হয়ে থাকে। অর্থাৎ কোন একটি প্রজাতির দেহকোষে দুই
Exocrine gland
যে সব গ্রন্থির নালী থাকে ও নিঃসারক রস নালীর মাধ্যমে রক্তে, লসিকায় বা বিভিন্ন অঙ্গে নিঃসৃত হয়, তাদের বহিঃক্ষরা গ্রন্থি বলে। যেমন- লালা গ্রন্থি, পেপটিক গ্রন্থি, যকৃৎ, আন্ত্রিকগ্রন্থি, অগ্ন্যাশয় গ্রন্থি ইত্যাদি। এই গ্রন্থি থেকে বিভিন্ন ধরনের উৎসেচক ক্ষরিত হয়। নালীর
Eye
Eye is an organ of vision. It is a kind of receptor organ that detects light wave and convert it into electro-chemical impulses in neurons. Like higher animals fishes have a pair of eyes. Fish eyes are similar to terrestrial
Estivation
Estivation (also spelled “aestivation”) is a situation of inactivity and a lowered metabolic rate of animal during summer as well as dry season. Most of all coldblooded (also known poikilothermic or ectothermic) animals take position in the time of hotness
Ear
Ear is a kind of receptor organ (also called receptors) of vertebrates that detects sound. It is also assists with balance and body position. It is a main part of the auditory system of higher animals. Ear is divided into
Eukaryotic cell
Cells that do have a membrane-bound nucleus are called eukaryotic cell. Cells except most of all bacteria and archaea are the example of eukaryotic cell. On the other words it is say that eukaryotic cell found in many unicellular organisms
Eukaryotes
The eukaryotes are a group of organisms whose cells do have a membrane-bound nucleus (karyon). Organisms except most of all bacteria and archaea are eukaryotes. Many unicellular organisms like protozoa and all multicellular organisms like fungi, plants and animals are
Epidermis
Epidermis is the outer edge of the skin of vertebrates which is composed by two or more layers of epithelium or epithelial cell and originated from embryonic ectoderm. The word epidermis is created form Greek word “epi” means “over” or
Ectothermic animal
An organism having irregular (not constant) body temperature that means their body temperature changes with the temperature of its surrounding environment. Such as all invertebrates as well as vertebrates except birds and mammals. Ectothermic (Greek word “ektos” means “outside” and
Endothermic animal
An organism having a constant body temperature such as in humans the average internal temperature is 37.0 °C (98.6 °F). Endothermic animal (also known homeothermic animal) is able to regulate its body temperature with the help of two biological mechanisms
Eucoelomata
Eucoelomata is the group that includes eucoelomates. Animals having a true coelom are called eucoelomates (singular- eucoelomate). Examples of eucoelomata: Group that includes the phylum Mollusca, Annelida, Arthropoda, Echinodermata, Chordata etc. Eucoelom is a fluid filled body cavity between the
Eucoelomates
Animals having a true coelom are called eucoelomates (singular- eucoelomate). On the other hand, eucoelomata is the name of group that includes eucoelomates. Examples of eucoelomets: Animals of the phylum Mollusca, Annelida, Arthropoda, Echinodermata, Chordata etc. Eucoelom is a fluid
Eucoelom
Eucoelom is a fluid filled body cavity between the most inner membrane (parietal peritoneum) of body wall and the most outer membrane (visceral peritoneum) of alimentary canal and other internal organs (liver, heart, lung etc.) of an animal. It is