Overview of Development and Genomic Equivalence. Flashcards
Define fertilisation?
The union of 2 gametes (sperm and egg) to form a zygote.
Define gametogenesis?
The production of eggs in women and sperm in men.
Define organogenesis?
The interactions and cell movements that occur to produce various body organs.
What is cleavage characterised by?
By rapid cell divisions in the cytoplasm of a zygote cytoplasm to blastomeres.
What is a blastula?
A hollow ball of blastomere cells.
What occurs in gastrulation?
The point of development where the cells of the embryo
for 3 distinct germ layers.
What are the 3 germ layers that are formed during gastrulation?
Ectoderm.
Mesoderm.
Endoderm.
What are the 3 body parts that are formed by the ectoderm?
The epidermis.
The brain.
The spinal cord.
What are the 6 body parts that are formed by the mesoderm?
Muscle.
Skeletal tissue.
Blood.
Heart.
Kidneys.
Gonads.
What are the 2 body parts that are formed by the endoderm?
The gut.
Respiratory tract linings.
What are the 7 stages of the reproductive cycle, from birth to maturity?
Gametogenesis.
Fertilisation.
Cleavage.
Gastrulation.
Organogenesis.
Larval stages.
Maturity.
Define embryonic development?
The process of change that transforms a fertilized egg into a complex multicellular organism.
What is reproduction characterised by?
The production of a fertilised egg from 2 gametes.
What is embryonic development characterised by?
The development of a zygote to form larvae or a juvenile organism.
What is metamorphosis characterised by?
The development of larvae into an adult.
What is maturation characterised by?
The development of a juvenile organism into an adult.
What is senesence characterised by?
Adulthood to death.
Define preformation?
The belief that mini organisms were found in the embryo and that they got bigger during development.
Define epigenesis?
The belief that an embryo develops progressively from an undifferentiated egg cell.
What would be an example of a totipotent cell?
A cell that can form any cell within the body, including the placenta and umbilical cord.
Define a pluripotent cell?
A cell who can develop into any cell within the body, except for the placenta and umbilical cord.
Define a determined cell?
When a cell and its progeny are irreversibly committed to one become one partiular cell type.
Define a differentiated cell?
A cell that exhibits a clear phenotype that can identify it as a specialised cell.
All cells within an embryo are descended from what?
A fertilised egg.
What was Rouxs developmental experiment and what was his conclusion?
He took a 2 celled blastomere and destroyed 1 cell and only half the embryo developed.
He concluded that half of the total genetic material was found in each cell.
The bastomere cells of a balstula have what potency or genetic potential?
They are totipotent.
What did Dreisch discover after his experiment?
He separated a cell blastomere into individual cells and each cell developed into an embryo.
He concluded each cell has the possibility to develop and form an organism.
Do the cells of the embryo remain totipotent forever?
No, totipotency will decrease as the embryo gets older .
What kind of cells are found in an embryo after they have lost their totipotency?
Pluripotent cells.
What will lead to the production of identical clones?
The transplantation of nucei that have been donated from the same individual produces identical clones.
All somatic cells will retain what throughout development?
The same genes.
Does cell differentiation arise from the loss of genes?
No, cell nver lose genes, they just express different genes and this is known as differential gene expression.
What are luxury genes?
Specialised genes that are expressed by specific cell types.
E.g. A liver cell will express different luxury genes to a muscle cell.
What determines a cells phenotype?
The type of luxury genes that are expressed by that cell.
What are house keeping genes?
Genes expressed by almost every cell in the body and they provide proteins for cell structure and metabolism.
