Coding 1 & 2 Flashcards
1
Q
What is development?
A
A multicellular organism generate a complex where the genotype and environment form the phenotype of cells
1
Q
What is oviparity?
A
Born from eggs ex., fish
2
Q
What is viviparity?
A
Born from live eggs ex., human
3
Q
What is oviviparity?
A
Born from hatching ex., chicks
4
Q
What is between birth and fertilization?
A
An embryo
5
Q
What is differentiation?
A
Cell specialization
6
Q
What is morphogenesis?
A
An organized manner of cells specializing
7
Q
What regulates cleavage?
A
The proteins and RNA in the oocyte cytoplasm
8
Q
Does the volume of the cell change during cleavage?
A
No the number of cells increases with cell division
9
Q
What factors do model organisms depend on?
A
- Size - can it fit in the space
- Generation time - embryo to adult
- Embryo accessibility
- Organism type and phylogenetic position
- Ease of experimental manipulation
10
Q
Where does the sperm enter from?
A
Through a dimple called the blastopore
11
Q
What is the blastopore in frogs analogous to in humans?
A
The primitive streak
12
Q
What is embryogenesis?
A
The collection of stages between births and death
13
Q
What is fertilization?
A
When the maternal and paternal pro nuceli from the egg and sperm respectively fuse
14
Q
What is cleavage?
A
Following fertilization the zygote cytoplasm divides into cells
15
Q
What are the cells that form during cleavage called?
A
Blastomeres
16
Q
What is the morula?
A
That is the embryo in the intial phase of cleavage that lacks a cavity
17
Q
What is a blastula?
A
That is the embryo in the later phase of cleavage that has a cavity
18
Q
What is gastrulation?
A
This is the movement of cells that forms the germ layers
19
Q
What is the gastrula?
A
That is the embryo in the gastrulation phase
20
Q
What is organogenesis?
A
The formation of the organs following the formation of the germ layers
21
Q
What is the best way to describe species development?
A
As a cycle
22
Q
What is the yolk sac?
A
The membranous sac outside of the embryo that provides protection to the developing embryo
23
Q
What is the zygote?
A
A single-celled organism
24
What are model organisms?
The basis for understanding various process or biochemical functions in similar animals
25
What are the 3 steps in determining the function of a gene?
1. Determine the location of gene expression
2. Knockout the gene
3. Explore different mutations
26
What is the TBX5 gene responsible for?
The forelimb and heart development
27
What is the phenotype of a heterozygous mutation in the TBX5 gene?
Lack of the forelimb bone development
28
What is the phenotype of a homozygous mutation in the TBX5 gene?
No forelimbs
29
Why is the heart not impacted in the TBX5 gene?
Conditional specification
30
What is haploinsufficiency?
When 1 normal copy of the gene is not enough to form the wild type phenotype
31
What is haplosufficiency?
When 1 normal copy of the gene is enough to form the wild type phenotype
32
Why is the location of gene expression important?
Where the gene is expressed can tell you what the function is
33
What is the anterior?
The head
34
What is the posterior?
The tail
35
What is the ventral?
The front
36
What is the dorsal?
The back
37
What is the proximal?
The centre
38
What is the transverse plane?
Cross section ex., stomach
39
What is the midsagittal plane?
Down the middle ex., between the eyes
40
What is the horizontal plane?
Horizontal cut ex., hot dog bun cut
41
In vertebrae organogenesis what forms the notochord?
The cells of the mesoderm
42
What forms the episdermis?
The notochord cells redirect the surrounding ectoderm cells
43
What is the embryo when the neural tube is forming?
The neurula
44
What forms the neural tube?
The neural precursor cells which are instructed by the notochord
45
What happens after the notochord forms?
The surrounding regions continue organogenesis and form somites which begin to form the nervous system by instructing the ectoderm
46
When does the vegetal pole form in the embryo?
Later in cleavage
47
What is the purpose of the vegetal pole?
The vegetal pole is the side of the yolk that divides slowly and leads to the formation of membranes and nourishment for the embryo
48
What is the blastula called in a mammal?
Blastocyst
49
What is meroblastic cleavage?
The whole egg does NOT undergo cleavage
50
What is holoblastic cleavage?
The whole egg does undergo cleavage
51
What determines meroblastic or holoblastic cleavage?
The amount of yolk determines which type of cleavage it undergoes
52
What are the main patterns of cleavage?
For holoblastic cleavage the embryo divides and is hollow but for meroblastic cleavage the cells divide and sit on top or surrounding the yolk
53
Does the yolk inhibit cleavage?
Yes
54
is the notochord transient?
Yes, it is temporarily expressed but it is a critical structure formed by the mesoderm in vertebraes
55
What are epithelial cells?
These are cells that are tightly bound and connected in sheets and tubes
56
What are mesenchymal cells?
These are loosely indpendent units that are floating around
57
What are mesenchymal cells used for?
1. Cell division
2. Cell migration
3. Cell shape and changes
4. Cell growth
5. Cell death
6. Changes in cell membrane composition
58
What is the ectoderm?
The exterior layer ex., skin
59
What is the mesoderm?
The interior layer ex., blood and heart
60
What is the endoderm?
The innermost layer ex., the digestive tract
61
How can you visualize cell fate by injection?
The injection of a fluorescent dye to observe gene expression
62
How can you visualize cell fate by a virus infection?
Infect the embryonic cells with a virus that has been altered to express green fluorescent proteins
63
What is a transgene?
A gene that contains the DNA from another species
64
What is Van Baer's law of embryology?
That there is a phase in early embryology where all species look relatively the same
65
What is invagination?
The infolding of the epithelial sheets of a gastrula ex., sea urchin mesoderm
66
What is involution?
Inward movement of an expanding outer layer that spreads over the internal surface ex., amphibian mesoderm
67
What is delamination?
Splitting of one cellular sheet into 2 sheets of epithelium ex., hypoblast formation in birds and mammals
68
What is ingression?
Migration of cells through EMT into the embryo's interior ex., sea urchin mesoderm
69
What is epiboly?
Movement of epithelial sheets using ectodermal cells spreading as a unit to enclose the interior layers ex., ectoderm of tunicates, sea urchins, amphibians, and zebrafish
70
What is convergent extension?
The movement of more lateral cells of all germ layers towards the midline ex., ectoderm and mesoderm of amphibian, zebrafish, birds, and mammals
71
What is cell commitment?
When cells specify and mature
72
What is differentiation?
When cells form organs of varying types with unique traits
73
What happens when a cell commits?
There may be no change in biochemistry or function but it may have committed to form a cell or organ
74
What are the 2 steps of commitment?
Specification then determination
75
What happens when a cell is specified autonomously?
The cell is in a neutral environment by itself and continues to follow its fate but it is labile in this stage or reversible
76
What happens when a cell is determined autonomously?
The cell is committed to its fate even in the presence of other neighbouring cells and it is not reversible
77
What is cell fate?
The cell's path to differentiating in an undisturbed embryo
78
What does the egg cytoplasm contain to lead to cell fates being determined?
Transcription factors
79
In autonomous specification when do blastomeres know their fate?
Very early on through cytoplasmic determinants
80
What is conditional specification?
When the neighbouring cell secrete signals that lead to the cells fate
81
How does a nucleus determine fate?
The fate of emryo's nucleus is determined by its location
82
What happens from
specification->determination->differentiation?
Potency decreases
83
What does autonomous specification need to take place?
Blastomeres acquire determination factors from the egg cytoplasm
84
What is mosaic development?
When autonomous specification leads to the blastomeres producing parts of the organism like tiles of a mosaic
85
What are blastomere in conditional specification?
Totipotent
86
What is regulative development?
The embryo can respond to removal of parts of the embryo a few cells
87
What is a syncitium?
When the cell contains many nuclei and the cell failed to develop a cell membrane to divide just a common cell membrane
88
Does a cell membrane form eventually?
Yes, around each nuclei via cellularization
89
What happens to the mRNA?
It is tethered to one side of the embryo and the proteins are then secreted and forms a gradient
90
What are morphogens?
These are components that can travel far and influence many cells and form a gradient only in a syncitia can transcription factors be a morphogen because there is no cell membrane
91
What are determinants?
These are components that can only influence the cell its made in not far like a morphogen
92
What signalling molecule is most likely a morphogen?
Paracrine or juxtacrine factors
93
What signalling molecule is most likely a determinant?
Autocrine factors
94
What is totipotent?
The zygote and it can produce all the cells that it need
95
What is pluripotent?
Embryonic stem cell
96
What is multipotent?
Tissue specific stem cell
