🧬 Embryo Development & Stem Cells

What is a model organism in developmental biology?

An organism used to study development because it is easy to maintain, manipulate, and has relevance to other species. Examples: zebrafish, Xenopus, chick, mouse.

What is pattern formation?

The process by which cells acquire positional information and differentiate into spatial patterns during development.

What is organogenesis?

The formation and development of organs from germ layers.

What are the three germ layers?

Ectoderm (skin, nervous system), mesoderm (muscle, bone, blood), endoderm (gut, lungs, liver).

What is a stem cell?

A cell that can self-renew and differentiate into specialised cell types.

What is the difference between embryonic and adult stem cells?

Embryonic = pluripotent, can become any cell type. Adult = multipotent, limited to certain lineages.

What is an induced pluripotent stem cell (iPSC)?

A adult cell reprogrammed to pluripotency by introducing specific transcription factors.

What is an organoid?

A 3D mini-organ grown in vitro from stem cells. Mimics structure and function of real organs.

What is a signalling pathway in development?

A cascade of molecular events that transmits signals to control gene expression and cell behaviour. Examples: Wnt, Notch, Hedgehog, BMP.

Why is developmental biology relevant to disease?

Many diseases arise from developmental defects or reactivation of developmental programmes (e.g., cancer