Studied by 0 peoplegoal of development
adult body
stages of development
cleavage
gastrulation
neurulation
growth
cleavage
make cells (skip G1 and G2)
no change in size
gastrulation
rearrangement of cells into three major body tissues
ectoderm
mesoderm
endoderm
ectoderm
skin and nerve
mesoderm
muscle and bone
endoderm
digestive tract and lungs
neurulation
making of backbone
totipotent
cells that can become anything
pluripotent
can become many things (limited)
transcription factors
proteins that bind to DNA at promoter regions or enhancers
job of transcription factors
to stimulate or repress gene expression
structure/function in TFs
shape of protein (TF) defines its function
binds to DNA
information flow in TFs
info in DNA makes proteins needed at right time/place
regulates which genes become proteins
regulation of body plan
one gene regulates expression of many genes
one TF regulates group of genes
trophoblast
cells that become placenta
inner cell mass
cells that become the embryo
therapeutic cloning
producing genetically identical stem cells
regulation of gene expression
must be way to turn on/off genes
control
transcription control
DNA methylation
enhancers
DNA methylation
methyl groups added to C bases in promoters/enhancers
blocks transcription factors and their access to information
enhancers
responsible for differences in genetically similar species
post-transcriptional control
controls availability of mature mRNA
splicing and polyA tail
translational control
quick way to get proteins
RNA interference
RNA interference
mRNA blocked by proteins
miRNA acts as on/off switch
post-translational control
protein folding/modification
inactive →active protein
cell signaling
cells need to monitor environment and communication with other cells
ligand
molecule that signals
receptor
protein that binds ligand
autocrine
cell signals itself
juxtacrine
cell signals neighbor
paracrine
cell signals nearby
endocrine
cell signals far away
hydrophobic ligands
pass through membrane
use intracellular receptors
hydrophilic ligands
cannot pass through membrane
use membrane receptors
kinase
adds phosphate group to protein
phosphatase
removes phosphate group from protein
concept of gene
factor somewhere in cells cause appearance
two factors in each cell - one can be dominant over the other
genes are the factors, versions of genes are alleles
genes are on chromosomes in nucleus
genes are DNA
allele
version of a gene
monohybrid cross
follows two variations of one gene
homozygous
two of the same allele
heterozygous
two different allele
principle of segregation
two alleles segregate in gametes during meiosis and rejoin at random during fertilization
test cross
crossing with recessive
used to tell genotype
dihybrid cross
follows two genes
principle of independent assortment
alleles for each gene separate independently
sex linked
alleles attached to sex chromosomes
hemizygous
only one allele is present
sex linked
incomplete dominance
heterozygote is intermediate between two homozygotes
ex: red + white = pink
co-dominance
each allele is fully seen in phenotype
ex: ABO blood group
Note
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