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। >>>

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 >>>


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 >>>


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 >>>


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 >>>

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 >>>


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 >>>


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 >>>

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 >>>

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 >>>