Shared Flashcard Set

Details

ch 21 terms
blah
52
Biology
11th Grade
12/10/2007

Additional Biology Flashcards

 


 

Cards

Term
drosphila fruit fly
Definition
chosen by TH morgan
generation time of 2 weeks
180 million bases, and 13,700 genes.
Term
nematode
Definition
matures in 3.5 days.
genome is 97 million bases long.
19,000 genes.
they are hermaphrodites
Term
model organism
Definition
an organism chosen for study, nemotode, fruity fly etc.
Term
Mouse
Definition
this is a vertebrate.
genome is 2,600 million base pairs
25,000 genes. about the same as humans
generation time of 9 weeks
Term
Zebrafish
Definition
embryos develop outside mother
generation 2-4 months.
early and fast development by the first 24 hours
1700 Million base pairs long
Term
common wall cress
arabidopsis thaliana
Definition
in the mustard family
can germinate and produce thousands in 8 weeks.
118 million base pairs long
25,500 genes
Term
cell differentiation
Definition
process in which cells become specialized in structure and function, organized into tissues/organs
Term
morphogenesis
Definition
"creation of form," organized into tissues and organs
Term
animal development
Definition
blastula - sphere of cells surrounding a fluid filled cavity.
when this folds inward it is a gt, gastrula.
Term
plant development
Definition
in morphogenesis - cell division and cell wall expansion rather than cell tissue movement in animals. apical meristems develop.
Term
genomic equivalence
Definition
they all have the same genes
Term
FC steward
Definition
worked with carrot plants, showed that cell differentiation does not necessarily involve irreversible changes in the DNA.
Term
apical meristems 
Definition
structures responsible for plants continual growth and formation of new organs @ the tips of shoots and roots.
Term
topipotent  
Definition

mature cells can dedifferentiate and then give rise to all the specialied cell types of the mature organism.

 

ability of a single cell to divide and produce all the differentiated cells in an organism, including extraembryonic tissues.

Term
nuclear transplantation  
Definition
remove the nucleus of an unfertilized egg cell or zygote and replace it with the nucleus of a differentiated cell.
Term
Robert Briggs, Thomas King and Extended by John Gurdon  
Definition

they transplanted a nucleus from an embryonic or tadpole cell into an enucleated egg of the same species.

 

concluded that: something in the nucleus does change as animals differentiate. nuclear potency 

Term
stem cell  
Definition
relatively unspecialized cell that can both reproduce itself indefinetely and under appropriate conditions differentiate into specialized cells of one or more types.
Term
pluripotent  
Definition

able to give rise to multiple but not all cell types,

 

contrast of totipotent embryonic stem cells 

Term
therapeutic cloning  
Definition
cloning to produce embryonic stem cells to treat disease
Term
determination  
Definition

the events that lead to the observable differentiation of a cell

 

the out come of differentiation is marked by the expression of genes for tissue specific proteins.  

Term
tissue specific proteins
Definition
proteins found only in a specific cell type and give the cell its characteristic structure and function
Term
myoblast 
Definition
is a type of stem cell that exists in muscles.
Term
cytoplasmic determinants
Definition
maternal substances in the egg that influence the course of early development
Term
induction
Definition

signal molecules cause changes in nearby target cells.

 

signal molecules usu change their gene expression and this results in observable cellular changes. 

Term
pattern formation
Definition

development of a spatial organization in which the tissues and organs of an organism are all in their characteristic place.

 

"setting up and animals body" 

Term
positional information
Definition
the molecular cues that control pattern formation, provided by cytoplasmic determinants and inductive signals.
Term
metamorphosis
Definition
change from larva to adult fly.
Term
Edward B. Lewis
Definition

this revealed the specific molecules that guide development.

he used mutants to investigate fly development. located abnormalities to specific genes.

GENES DIRECT THE DEVELOPMENTAL PROCESSES. 

Term
Nusslein-Volhard and Eric Wieschaus.
Definition
studied pattern formation during early development. tried to identify all the genes that affect segment formation.
Term
embryonic lethals
Definition
mutations with phenotypes causing death at embryonic or laval stage, these never reproduce and cannot be bred for study.
Term
maternal effect gene
Definition
a gene that, when mutant in the mother, results in a mutant phenotype in the offspring, regardless of genotype.
Term
egg polarity genes
Definition
maternal effect genes are these. control the oreientation (polarity) of the egg and the fly.
Term
gradient hypothesis
Definition

gradients of substances called morphogens establish an embryos axes and other features of its form

 

 

Term
morphogen
Definition
 a substance governing the pattern of tissue development and, in particular, the positions of the various specialized cell types within a tissue. It spreads from a localized source and forms a concentration gradient across a developing tissue.
Term
segmentation genes
Definition
genes of the embryo whose products direct formation of segments after the embryos major body axes are defined.
Term
3 sets of segmentation genes
Definition
gap genes, pair rule genes and segment polarity genes.
Term
homeotic genes
Definition
the segments set by master regulatory genes, discovered by Edward Lewis
Term
nematodes are very useful in research of
Definition
cell signaling.
Term
cell lineage
Definition
the entire ancestry of every cell in the body. shows the fate of all the cells in the developing embryos
Term
vulva
Definition
arises from 6 precursor cells on the embryos ventral surface
Term
apoptosis
Definition

programmed cell death.

2 genes in nemotodes are ced-3 and ced-4 

Term
caspases
Definition
the main proteases of apoptosis, these are activated the by apoptosis pathways and cut up DNA
Term
three proteins critical to apoptosis
Definition
ced3,ced4,ced9
Term
 John Sulston and Robert Horvitz
Definition
studied roles of induction and apoptosis during development of nematodes. advanced understanding of how genes regulate organ growth and process of programmed cell death.
Term
organs in a flower
Definition

carpels (contain egg cells)

stamens (contain sperm pollen)

petals

sepals(leaflike structures outside the petals) 

Term
chimeras
Definition
organisms with a mixture of genetically different cells
Term
organ identity gene
Definition

genes controlling organ identity, determines the type of structure that will grow from a meristem.

analogous to homeotic genes in animals 

Term
homeobox
Definition
a 180 nucleotide sequence, which specifies a 60 amino acid homeodomain in the protein
Supporting users have an ad free experience!