Animal development 1 Flashcards
What 5 processes are needed for development?
Cell division (cleavage) Pattern formation (spatial organisation of cells) Morphogenesis (changes in form) Differentiation (cell specialisation) Growth
How do genes influence development?
Gene expression controls cell behaviour by determining which proteins are made by the cell
The pattern of gene expression gives cells identity and makes them behave differently
What are the 5 key cell activities?
Cell-cell communication Cell shape changes Cell movement Cell proliferation Cell death (apoptosis)
What is the A/P axis?
The anterior/posterior axis (head/tail)
What is the D/V axis?
The dorsal/ventral axis (upper/lower) (back/front)
What does cranial refer to?
Cephalic/anterior (head)
What does rostral refer to?
Towards the oral/nasal region
What does caudal refer to?
Tail or tail like (posterior)
What is the P/D axis?
The proximal/distal axis (near/far)
What does medial refer to?
The middle
What does lateral refer to?
To the side
What does apical refer to?
At the apex, point, or tip
What does basal refer to?
At the base
What does the transverse (coronal) section refer to?
The cross-section
What does the sagittal (longitudinal) section refer to?
The lengthways section
What are the germ layers?
Endoderm
Mesoderm
Ectoderm
Describe pattern formation
Cells become organised in time and space and acquire an identity about what they will become (positional info)
The early stages involve cells being allocated to different germ layers that will give rise to different types of tissue
What does the endoderm form?
The gut, liver, and lungs
What does the mesoderm form?
The skeleton, muscle, kidney, heart, and blood
What does the ectoderm form?
The epidermis of the skin, and nervous system
What is mosaic development?
Specific determinants in the zygote are distributed unequally to the daughter cells during cleavage
The fate of each cell is predetermined in the egg by the factors it receives internally during cleavage- the cell’s environments cannot influence it
What is regulative development?
Depends on interactions between ‘parts’ of the developing embryo by cell communication
The cell’s environment can influence its developmental fate
The embryo is able to develop normally even when parts are removed or rearranged
