Prelims Exam Flashcards
(36 cards)
Who is considered the first embryologist?
Aristotle
He noted the formation of major organs by opening a 3-week incubated chick egg.
What is developmental biology?
The study of embryonic and other developmental processes starting from a zygote.
Define embryogenesis.
The process of a fertilized egg becoming an embryo.
What occurs during fertilization?
Fusion of the gametes’ nuclei gives genome to the embryo.
What is cleavage in embryonic development?
Zygote cytoplasm divides into blastomeres, forming a blastula.
What do inner and outer cells form during cleavage?
- Inner cell: Different cell types
- Outer cell: Contributes to placenta and nourishes the embryo.
What is gastrulation?
The process where the embryo differentiates into germ cells: mesoderm, ectoderm, and endoderm.
What is organogenesis?
The process where cells interact and rearrange to produce tissues and organs.
What is gametogenesis?
The process of setting aside gametes for reproduction.
What does comparative embryology study?
How anatomy changes during development.
What is evolutionary embryology?
The study of how developmental changes drive evolutionary shifts.
What is tetralogy in the context of embryology?
The study of birth defects.
Differentiate between epigenesis and preformation.
- Epigenesis: Organs form from scratch
- Preformation: Organs are already present in miniature form.
What are the three germ layers?
- Ectoderm: Produces skin, brain, and nervous system
- Mesoderm: Generates blood, heart, kidney, and muscles
- Endoderm: Produces digestive tube epithelium.
What are Karl Ernst von Baer’s principles?
- General features develop before specialized features
- A species’ embryo diverges from adult stages of lower animals.
What is morphogenesis?
The process through which cells, tissues, and organs acquire shape.
What are the two types of cells in the embryo?
- Epithelial: Tightly connected
- Mesenchymal: Unconnected, independent.
What are fate maps used for?
To identify which parts of the embryo become larval or adult structures.
What are homologous structures?
Organs from the same ancestry, e.g., wing of a bat and forelimb of a human.
What are analogous structures?
Same function but different ancestry, e.g., bird wing and butterfly wing.
What is differential gene expression?
The process where different genes are activated in a cell, defining its function.
Define stem cells.
Undifferentiated cells that can become any cell type depending on gene activation.
What are exons and introns?
- Exons: Coding regions of DNA or RNA
- Introns: Noncoding regions removed before mRNA translation.
What is the role of the TATA box?
A region within the promoter where RNA polymerase attaches to initiate transcription.
