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65 terms

Essential Biology Chapter 11: How Genes Are Controlled (Questions)

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(CH 11) ______ interacting with ______ turn ______ genes on or off in response to environmental changes
Proteins, DNA, prokaryotic
overall process of information flow from genes to proteins
Gene expression
level in which gene expression is controlled
transcription
gene is ____ ____ when it is being transcribed to produce mRNA that is translated to make its corresponding protein
"turned on"
organisms control gene expression in order to respond to _____ ____
environmental changes
group of genes under coordinated control in bacteria
operon
active repressor binds to the operator. inducer binds to and inactivates the repressor
inducible operon
common example of an inducible operon
lactose (lac) operon
includes three adjacent genes for lactose-utilization enzymes. Promoter sequence where RNA polymerase binds
lactose (lac) operon
____ ____ is where a repressor can bind and block RNA polymerase
operator sequence
if the operon is turned off, transcription does occur or does not occur
does not occur
binds to DNA to block RNA polymerase action in forming mRNA
repressor
the ________ of lactose in the repressor causes the repressor to bind to the operator and prevent RNA polymerase transcription
absence
a common example of a repressible operon
tryptophan (trp) operon
in a situation with a repressible operon the repressor is initially _____
inactive
in a situation with an inducible operon the repressor is initially _____
active
the operon is turned on and transcribed in the ______ of tryptophan
absence
a cell (usually embryonic) that has not specialized yet
stem cell
a group of genes under coordinated control in bacteria (located all in one line on the DNA)
operon
three adjacent genes for lactose-utilization enzymes, operator sequence where a repressor can bind and block RNa polymerase action
lac operon
allows cell to have glucose for cellular respiration, happens only in prokaryotic cells
lac operon
results from the expression of different combinations of genes. involves cell specialization, in both structure and function. Controlled by turning specific sets of genes on or off.
differentiation
muscle cells and red blood cells are both very _____ cells
specialized
multiple levels of folding and coiling that is undergone by eukaryotic cells. helps with gene expression. Can prevent transcription
DNA packing
formed when DNA is wrapped around 8 histone proteins
nucleosomes
proteins DNA wraps around in order to form nucleosomes
histones
during what phase of meiosis and mitosis represents the highest level of packing?
metaphase
in _____ mammals one X chromosome is inactive in each somatic cell
female
name for one X chromosome not being active in each somatic cell of a female mammal. Responsible for tortoiseshell fur coloration in heterozygous female cats
X-chromosome inactivation
In female mammals one of two X chromosomes is highly _____ and transcriptionally ______
compacted, inactive
the inactivation of either the maternal or paternal chromosome is _______
random
X chromosomal inactivation occurs _____ in embryonic development, and ____ cellular descendants have the same inactivated chromosome
early, all
inactivated X chromosome
Barr body
process of root cells cultured in nutrient medium, cell division within culture, plantlet, then adult plant.
plant cloning
plant cloning proves that differentiated cells may retain (all, some, or none) of their genetic potential
all
Gene that has its own promoter and terminator
Eukaryotic gene
promote RNA polymerase binding to the promoter
transcription factors
______ proteins bind to control sequences
regulatory
where activator proteins bind to and interact with other transcription factors
DNA enhancers
repressors that inhibit transcription
silencers
can be used to clone animals. replacing the nucleus of an egg cell or zygote with a nucleus from an adult somatic cell
Nuclear transplantation
early embryo
blastocyst
take blastocyst and implant it in female species' uterus. implant embryo in surrogate mother for development. new animal will be genetically identical to nuclear donor
reproductive cloning
used to produce animals with desirable traits. animals could then produce agricultural products, therapeutic agents, or restore endangered animals
reproductive cloning
remove embryonic stem cells and grow in culture for medical treatments. induce stem cells to differentiate
therapeutic cloning
can produce stem cells with great medical potential
therapeutic cloning
a cell of an undifferentiated embryo
embryonic stem cell
a cell that can be induced to give rise to differentiated cells
stem cell
a cell that can differentiate into a variety of types
embryonic stem cell
a cell that can give rise to many but not all types of cells
adult stem cell
a process that can supply cells to treat human diseases
therapeutic cloning
results from mutations in genes that control cell division
cancer
first person to connect a job with the onset of a cancer (believed chimney sweeps developed scrotum cancer b/c of the dust getting in the skin)
Perceville Pot
rare form of cancer that is in the eye and can spread to the brain, traveling through the optic nerves to the back of your brain. Happens in 1 in 20,000 children. Showed cancer could be genetic b/c occurred 3 times in one family.
Retinoblastoma
can cause skin cancer from being exposed to harmful rays through machinery. Marie Cury
X-ray radiation
can cause skin cancer from the sun
UV light
tell cell to keep dividing
proto-oncogenes
mutation in this gene can enhance its normal function, causing cancer
proto-oncogene
inhibits cell division
tumor-suppressor gene
mutation in this gene allows uncontrolled cell division to occur
tumor-suppressor gene
_____ or more somatic mutations are usually required to produce a cancer cell
four
inactivation of a tumor suppressor gene causes formation of a ______
benign tumor
additional mutations can lead to a _______
malignant tumor
a tumor that does not spread
benign tumor
(CH 11 - eof) a tumor that spreads
malignant tumor