Watson and Crick DNA Model

Watson and Crick DNA Model

DNA stands for Deoxyribonucleic acid which is a molecule that contains the instructions an organism needs to develop, live and reproduce. It is a type of nucleic acid and is one of the four major types of macromolecules that are known … Read more

Zebrafish Development

Zebrafish Development The teleost fish Danio rerio is commonly known as the zebrafish. It is a common small‐bodied tropical, freshwater species originally from South Asia.  The fish is a part of the Cyprinidae family, which includes carps, true minnows, barbs and … Read more

Implantation- Process, Events, Significance

Implantation- Process, Events, Significance The term “implantation” is used to describe the process of attachment and invasion of the uterus endometrium by the blastocyst (conceptus) in placental animals. It begins at the end of the first week and is completed … Read more

Heart Embryology- Development of the Heart

Heart Embryology- Development of the Heart The heart is a muscular organ located in the middle mediastinum that pumps blood through the circulatory system. It is one of the earliest differentiating and functioning organs in the human body. In human embryos, the … Read more

Developmental Biology

Developmental Biology

What is Developmental Biology? It is the field of biology that studies the processes by which multicellular organisms grow and develop, controlled by their genes.  It involves the study of mechanisms of development, differentiation, and growth in animals and plants at the molecular, cellular, genetic and evolutionary levels. … Read more

Stages of Childbirth

Stages of Childbirth

Stages of Childbirth Labor is a physiologic process during which the fetus, its associated membranes, the umbilical cord, and the placenta are expelled from the uterus. During most of the months of pregnancy, the uterus undergoes periodic episodes of weak … Read more

Drosophila Development- Stages, Significance

Drosophila Development- Stages, Significance The fruit fly Drosophila melanogaster has been extensively studied for over a century as a model organism for genetic investigations. It also has many characteristics that make it an ideal organism for the study of animal development and behavior, … Read more

Development of Caenorhabditis elegans

The nematode worm Caenorhabditis elegans is a small (1 mm long), unsegmented, vermiform, free-living soil nematode. It is a relatively simple, and precisely structured organism, extensively used as a model organism for molecular and developmental biology. The body of an adult C. … Read more

Blastocyst- Stages, Significance

The preimplantation period of human embryo development is remarkable and characterized by successive changes in terms of genetic control, physiology, and morphology of the embryo. Blastocyst (Greek, blastos= sprout + cystos = cavity) is a distinctive stage of mammalian embryo development, characterized by a … Read more

Human Embryo Transfer

Human Embryo Transfer

‘Embryo transfer’ refers to the transplantation of a mammalian preimplantation embryo into the reproductive tract of a recipient female so that it may implant and continue to develop to birth. Mammalian embryos of many species can develop in vitro from fertilization to … Read more

Human Embryogenesis

Human embryogenesis refers to the development and formation of the human embryo. It encompasses the first eight weeks of development after fertilization, in which a single cell formed at fertilization turns into an organism with a multi-level body plan. It … Read more

Gastrulation- Process, Consequences

The most characteristic event occurring during the third week of gestation is gastrulation. Gastrulation is a formative process by which the three germ layers, which are precursors of all embryonic tissues, and the axial orientation are established in embryos. During … Read more

Comparative Embryology- Principle, Significance

Comparative embryology is the branch of embryology that compares and contrasts embryos of different species, showing how all animals are related. Put simply, comparative embryology is the comparison of embryo development across species. All vertebrate embryos follow a common developmental path due to their common ancestry. … Read more

Epiblast- Development and Significance

Epiblast- Development, and Significance As implantation of the blastocyst occurs, morphologic changes in the embryoblast produce a bilaminar embryonic disc composed of epiblast and hypoblast cells. Epiblast is derived from the inner cell mass and lies above the hypoblast.  The … Read more

Morula- Stage, Development, Significance

Within twenty-four hours after fertilization, the zygote initiates a rapid series of mitotic cell divisions called cleavage. These divisions are not accompanied by cell growth, so they subdivide the large zygote into many smaller daughter cells called blastomeres. The first … Read more

The Prenatal Developmental Period

The human body, like that of most animals, develops from a single cell produced by the union of a male and a female gamete (or sex cell).  Cell division, cell migration, programmed cell death (apoptosis), differentiation, growth, and cell rearrangement transform the fertilized oocyte, a … Read more

Evolutionary Embryology

Embryology, the study of embryos, is an important cornerstone of biological evolution and can be used to help determine similarities and differences between various species. An embryo of an organism is the fertilized egg as it goes through the processes of development that is … Read more

Introduction to Embryology

Introduction to Embryology

Human development is a continuous process that begins when an oocyte (ovum) from a female is fertilized by a sperm (spermatozoon) from a male. Cell division, cell migration, programmed cell death (apoptosis), differentiation, growth, and cell rearrangement transform the fertilized … Read more