Embryonic development -- Lecture 19

Question 1

embryonic development (definition)

Answer 1

process of gene-directed changes that occur after fertilization that lead to the formation of an organism

Question 2

4 subprocesses of embryonic development:

Answer 2

(1) cell division
(2) cell differentiation
(3) pattern formation
(4) morphogenesis

Question 3

embryonic development:

4 subprocesses:

(1) cell division

Answer 3

cleavage

Question 4

embryonic development:

4 subprocesses:

(2) cells differentiation

Answer 4

cells become particular cell-types

Question 5

embryonic development:

4 subprocesses:

(3) pattern formation

Answer 5

cells detect positional information w/in the embryo, a body plan takes shape

Question 6

embryonic development:

4 subprocesses:

(4) morphogenesis

Answer 6

the form of the body (organs and anatomical features) take shape

Question 7

cell division in development:

cleavage:

animal embryos have a ___ cleavage (cell division) following ___

Answer 7

rapid

fertilization

Question 8

cell division in development:

cleavage:

how do cells in the embryo divide?

so, initially, the size of the embryo ___

Answer 8

of cells increases but size of cells decrease (no cell growth b/n divisions)

does not change

Question 9

cell differentiation in development:

in the 1-16 cell stage, are human embryonic cells able to became any cell type?

Answer 9

yes

Question 10

cell differentiation in development:

cell differentiation (definition)

Answer 10

as development proceeds, cells differentiate – commit to becoming particular cell types

Question 11

cell differentiation in development:

what determine’s a cell’s fate?

Answer 11

exposure to different ligands

physical contact w/ other cells

Question 12

cell differentiation in development:

cells ultimately adopt a fate appropriate for their ___

Answer 12

location in the embryo

Question 13

cells differentiate in stages:

totipotent cells (what are they)

Answer 13

can become any cell type

Question 14

cells differentiate in stages:

pluripotent cells (what are they)

Answer 14

inner cell mass cells can become any cell type except placenta

Question 15

cells differentiate in stages:

multipotent cells (what are they)

Answer 15

can become only certain cell types

Question 16

cells differentiate in stages:

unipotent cells (what are they)

Answer 16

can be only 1 cell type (fully differentiated)

Question 17

cell differentiation and cancer:

differentiated cells can acquire mutations allowing them to ___, in early stages of ___

Answer 17

dedifferentiate

oncogenesis

Question 18

cell differentiation and cancer:

dedifferentiated cells are able to ___ the cell cycle and become ___ (tumor formation and metastasis)

Answer 18

re-enter

mobile

Question 19

pattern formation in development:

embryonic cells use ___ information in the embryo to determine the ___ of the organism

Answer 19

positional

basic body plan

Question 20

pattern formation in development:

positional information leads to changes in a cell’s ___

Answer 20

gene expression

Question 21

pattern formation in development:

cells ultimately adopt a fate appropriate for their ___ in the embryo

Answer 21

location

Question 22

pattern formation:

radially symmetrical embryos develop ___ to define the basic body plan

Answer 22

axes

Question 23

pattern formation:

2 axes:

Answer 23

anterior-posterior axis

dorsal-ventral axis

Question 24

pattern formation:

polarity (definition)

Answer 24

the acquisition of axial differences in a developing organism

Question 25

morphogens in pattern formation:

morphogens (definition)

Answer 25

diffusible ligands that affect cell fate during development

secreted from a certain group of cells called organizers

or they can come from the mother

Question 26

morphogens in pattern formation:

morphogen gradient

Answer 26

high concentration at one end

gradient in b/n

low concentration at other end

Question 27

morphogens:

morphogen gradient provides ___

different ___ affect gene expressions differently

Answer 27

positional cues

different concentrations affect gene expressions differently

Question 28

morphogens:

organizer (definition)

Answer 28

cluster of cells that release morphogens that will affect the fat of the cells around it

Question 29

morphogens:

notochord (definition)

Answer 29

organizer that secretes morphogens to stimulate Neurulation (formation fo the brain, spinal cord, vertebrae)

Question 30

morphogens:

notochord ___ after development

Answer 30

disappears

Question 31

morphogens:

___ is a morphogen involved in neurulation

Answer 31

sonic hedgehog

Question 32

morphogens:

sonic hedgehog (definiton)

Answer 32

morphogen discovered in Drosophila

morphogen secreted by organizers

guides neurulation and other developmental processes in Drosophila

Question 33

naming of sonic hedgehog (SHH):

mutation of SHH results in ___

Answer 33

embryos covered in small pointy projections