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
DNA stands for Deoxyribonucleic Acid which is a molecule that contains the instructions an organism needs to develop, live and reproduce. These instructions are found inside every cell and are passed down from parents to their children. It is a nucleic … Read more
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 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 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
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 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 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
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
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
DNA Methylation Definition DNA methylation is a process by which methyl groups are added to the DNA molecule. It is an epigenetic mechanism that occurs by the addition of a methyl (-CH3) group to DNA, thereby often modifying the function of the genes and affecting gene expression. … Read more
‘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 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
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 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 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
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 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
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
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