Embryonic development

zygote

A fertilised egg

Morula

A solid ball of cells that has undergone mitosis to divide to 2 cells up to 16 cells.

Blastocyst

A fluid-filled sphere formed about 5 days after fertilization. Cell differentiation begins. Has an outer cell layer that becomes the placenta and an inner cell mass that will become the embryo

gastrula

An embryonic stage in animal development encompassing the formation of three layers: ectoderm, mesoderm, and endoderm.

Differentiation

process in which cells become specialized in structure and function

embryo

the developing organism from 3 weeks after fertilization through to the second month where organs begin to develop

foetus

what the embryo developing in the uterus is known as from eight weeks onward. Major organs have developed.

stem cells

unspecialized cells that are able to renew themselves for long periods of time by cell division

embryonic stem cells

An undifferentiated cell, taken from an embryo that has potential to give rise to various other cell or tissue types

Endoderm

the inner germ layer (of cells) that develops into the lining of the digestive and respiratory systems, the lining of the liver, pancreas and other organs

Mesoderm

middle germ layer; develops into muscles, bone, blood, kidneys, connective tissue and related structures and much of the circulatory, reproductive, and excretory systems

Ectoderm

outermost germ layer; produces sense organs, nerves, tooth enamel and outer layer of skin

Germ layers

Three main layers that form the various tissues and organs of an animal body.

pluripotent stem cells

can differentiate in to all types of tissues and cells in the body.

Multipotent stem cells a

can differentiate in to several different cell types

Totipotent stem cells

can differentiate into any type of specialised cells found in organisms of that species.

Unipotent

describes the condition of being committed to a single specialized cell type

adult stem cells

stem cells that are found in children and adults that can differentiate and form a limited number of cells

Gametes

a mature haploid male or female germ cell that is able to unite with another of the opposite sex in sexual reproduction to form a zygote.

Tissue

A group of similar cells that perform the same function.

Cells

Basic unit of life

Organs

Groups of tissues that work together to perform a specific function or related functions

Body Systems

Groups of bodily organs acting together to perform one or more functions.