Cell Cycle NJCTL Notes Flashcards
the life of a eukaryotic cell can be defined by the … between cell divisions. when a parent cell divides (mitosis) it produces … Over time each daughter cell will go through a series of events that will lead to the daughter cell becoming a …
time; 2 daughter cells; parent cell
the cell cycle is the stages a cell goes through from .. to ….
It includes these stages: … (M), … (I), … (G1), … (S), …(G2), … (G0)
division; division; mitotic phase; interphase; Gap phase 1; DNA synthesis phase; Gap Phase 2; Gap phase 0
(Mitotic Phase) this phase is the mechanical division of the … and … of the cell which results in full cell division. both daughter cells will enter … phase after the mitotic phase is complete
nucleus; cytoplasm; G1
(Mitotic Phase) After a cell completes its preparation for division, it enters the … phase. There are 2 sub-phases to the mitotic phase- … (the division of the …) and … (the division of the …)
mitotic; mitosis; nucleus; cytokinesis; cytoplasm
(Mitotic Phase) cleavage furrow: in .. only –> ring of .. that gets progressively smaller and pinches in
animals; microtubules
(Mitotic Phase) stages of mitosis: …, .., …, …, and …
prophase; prometaphase; metaphase; anaphase; telophase
(Cell cycle control) cells divide only when the correct set of … and … signals are present, allowing the cell to enter the next phase of the cell cycle. if a cell fails to recognize the proper conditions it will lead to … that should not occur, or … when its necessary
internal; external; divisions; no divisions
(Cell cycle control) when one is cut, cells… to fill the gap
divide
(Cell cycle control) density dependent inhibition: … control, cells are able to determine the .. of the cells around them by …. the more cells, the higher the level of signal
external; density; chemical signals
(Cell cycle control) for human tissue, a single cell layer covers it, otherwise it would be a
tumor
(Cell cycle control) anchorage dependence: many human cells require a … (…) to … to before they can divide. A signal from … in the … enable the cell to progress through the cell cycle.
substrate; surface; adhere; proteins; plasma membrane
(Cell cycle control) growth factors: … regulators; a growth factor is a naturally occurring substance capable of stimulating .., …, and … Usually it is a … or a …. They are important for regulating a variety of cellular processes
external; cellular growth; division; differentiation; protein; steroid hormone;
(Cell cycle control) growth factors typically act as … molecules between cells. examples are … and hormones that bind to specific receptors on the surface of their target cells.
without the correct growth factors present, a normal cell cannot …
signalling; cyclin; divide
(Cell cycle control) cell growth is further controlled by cell cycle … that ensure the proper division of cells. These checkpoints verify whether the processes at each phase of the cell cycle have been accurately completed before progression into the next phase. The cell cycle checkpoints are made up of … and … that all play roles in the maintenance of the cell division.
checkpoints; protein kinases; adaptor proteins
(Cell cycle control) cyclin-dependent kinases (CDKs) are a family of .. first discovered for their role in regulating the cell cycle. Kinases are enzymes that catalyze the transfer of a … from … to a … When activated, these proteins have a large impact on cellular processes.
CDKs must be activated by a chemical known as a … The complex is known as … (…)
protein kinases; phosphate group; ATP; specified molecule; cyclin; maturation promotion factor; MPF
(Cell cycle control) The CDK, cyclin, MPF control system is highly complex. Many factors are still unknown. The important pts are:
- various cyclins exist in the cell, each one signalling that a cellular activity has been …
- when cyclin and CDK combine and form high concentration of MPF in the cell, the cell will begin to …
- When chromosome pairs are successfully separated there is a release of a chemical that …, reducing … This low … induces the start of …
successfully completed; enter M phase; breaks down cyclin; MPF; MPF; G1 phase
(Cell cycle control) there is a cycle of cyclin … and …
production; degradation
(Cell cycle control) G1 checkpoint: the first checkpoint is located at the end of the cell cycle’s …, before entry into … This is a key point that dictates whether the cell should …, …, or enter a … High concentrations of particular … and … molecules signal the cell to move on to the … phase.
G1 phase; S phase; divide; delay division; resting stage; cyclins; CDK; S phase
(Cell cycle control) liver cells enter mitosis only … a year. The…. is where eukaryotes typically arrest the cell cycle if cell division is unnecessary or impossible. Then the cell passes into … for an extended period of …. or …
twice; G1 checkpoint; G0; no division; growth
(Cell cycle control) G2 checkpoint: the second checkpoint is located at the end of … phase, triggering the start of the .. phase. In order for this checkpoint to be passed, the cell has to check a number of factors to ensure the cell is ready for … Most importantly is that the chromosomes have … properly. If this checkpoint is passed, the cell initiates many molecular processes that signal the beginning of …
G2; M; mitosis; duplicated; mitosis
(Cell cycle control) metaphase checkpoint: the … checkpoint occurs at the point in metaphase where all the chromosomes have … The tension created by spindle fibers, the mechanism for …, is what is checked before division proceeds.
If this checkpoint is not passed the cell division will be .. and the cell will … If this mechanism has failed then the resulting daughter cells may be dangerous to the rest of the organism
mitotic spindle checkpoint; aligned at the mitotic plate; pulling chromsomes apart; halted; die
(Cell cycle control) when cells do not respond normally to internal or external signals and begin to divide when they are not supposed to, serious problems arise. They .., they … areas of the organism that should not be interfered with, and they could … the organism. These rogue cells are known as .. cells
divide uncontrollably; invade; kill; cancer
(Cancer) cancer is a general term for many diseases in multi-cellular organisms which is caused by .. cancer cells and normal cells are identical, with the exception that cancer cells …
cancer cells are non-responsive to the …, allowing them to constantly undergo …
uncontrolled cell division; divide uncontrollably; cell cycle control system; cytokinesis
(Cancer) the progression of cancer cells begins most often with a mutation in a … these are genes that promote normal cell division by producing …
when they become damaged and begin to cause too much cellular growth and division, then they are referred to as .., or …-causing genes
proto-oncogene; growth factors; oncogenes; tumor
(Cancer) an example of a proto-oncogene is the … gene, which is normally activated by a growth factor. When mutated, it can become .. and lead to excessive cellular division by triggering a …
ras; hyperactive; kinase cascade
(Cancer) an oncogene will cause a cell to ignore … or … this cell will proceed through the cell cycle. When it divides, the two daughter cells both have the … and quickly proceed through their cell cycle. As the process repeats, cells …, forming a …, as shown below
cell density; anchorage; oncogene; accumulate; tumor
(Cancer) once a tumor is formed it can be a serious problem for the organism. if the tumor remains localized and does not threaten the health of the overall organism it is called a … tumor. However, if left unchecked most tumors will cause more severe problems. Benign tumors may become malignant if …
benign; more mutations occur
(Cancer) If the tumor does not invade the … or other … it will remain benign
baasement membrane; tissues
(breast cancer) breast cancer awareness is focused on the idea of … if a tumor in the … is detected early, it minimizes the damage caused by the diseased cells and may only require a simple .. to remove the tumor. This is because, as tumor cells stay, they can spread and undergo … and …
early detection; mammary gland; surgery; metastasis; angiogenesis
(breast cancer) if a recently formed tumor is detected it is possible that the lump can be removed in a surgical procedure known as a … This is minimally invasive and the patient should return to normal quickly
lumpectomy
(breast cancer) if the tumor grows larger and interferes with the tissue of the … then it may be necessary to completely remove the … This is now a … tumor because it is interfering with … This … requires removal of the entire breast
mammary gland; mammary gland; malignant; normal organism functions; mastectomy
(breast cancer) f the tumor escapes the immediate surroundings and cancerous cells enter the blood or lymph systems the cancer has … It may now lead to cancer .. throughout the organism. This patient will require a … as well as … and … treatments to avoid tumors appearing in other organs
metastasized; spreading; mastectomy; chemotherapy; radiation
(breast cancer) metastasis is extremely dangerous to the host organism. With breast cancer, the most likely place for new cancer to appear is in the … Many forms of .. cancer are incurable.
brain; brain
(breast cancer) beyond metastasis, tumor cells can undergo … in which they induce the production of … to provide … that will sustain them
angiogenesis; blood vessels; nutrients
(breast cancer) It is also important to know family history. since we inherit genes from our parents, grandparents etc., certain people can be more likely to get cancers that their ancestors had. if a woman’s mother had breast cancer she is more likely to get breast cancer in her life, because they may have inherited … genes with the … allele, increasing their risk. proper precautions should minimize the damage
BRCA; mutated
(Meiosis) the sex cells or organisms are called … eggs in female animals, sperm in male animal; … and .., respectively in plants.
in many eukaryotic organisms, the somatic cells (those that are not …) have two sets of … (…).
Gametes have one set of … (…) and they are produced by ..
Sexual life cycles alternate between … and … phases
gametes; ovules; pollen; sex cells; chromosomes; diploid; chromosomes; haploid; meiosis; haploid; diploid
(Meiosis) Fusion of haploid gametes during fertilization results in a
diploid offspring
(Meiosis) the pairs of matching chromosomes in the somatic cells of diploid organisms are called …. In humans, each somatic cell contains … chromosomes, which make up …
homologous chromosomes; 46; 23 homologous pairs
(Meiosis) homologous chromosomes share … and … and .., each pair controlling the same … Each pair is inherited from the …, one from …, one from … (the sets are combined in the first cell following fertilization and then passed down by mitosis)
shape; size; genetic loci; inherited characteristics; parents; mother; father;
(Meiosis) synapsis: homologus pairs … to exchange segments of …, forming …
cross over; DNA; synpases
(Meiosis) a … is a photographic inventory of chromosomes- the chromosomes are digitally separated and ordered
karyotype
(Meiosis) homologous chromosomes can carry different versions of the same gene. These versions are called …
alleles
(Meiosis) Meiosis reduces … in diploid organisms to create sex cells.
Like mitosis, meiosis is begun by a single … of … Unlike mitosis, the overall result of meiosis is …, each with … the number of … (…)
chromosome numbers; duplication; chromosomes; 4 daughter cells; half; chromosomes; haploid
(Meiosis) the process involves 2 consecutive divisions, simply called … and ….
Halving the actual chromosome number occurs in … Then, the sister chromatids separate in …, resulting in … cells
Meiosis I; Meiosis II; Meiosis I; Meiosis II; 4
(Meiosis) prophase I: the … disappears and the … begins to form. … chromsomes (replicate during …) pair to form a …
nuclear envelope; spindle; homologous; interphase; tetrad
(Meiosis) crossing over occurs during .. this is a genetic rearrangement between 2 … that happens at a site called a …
crossing over increases the … of the offspring. Since this can occur several times at variable location in each tetrad, the variation which can occur between 2 parents is extremely large. This is one of the reasons that, with the exception of identical twins, everyone is a unique genetic entity
prophase I; homologus chromsomes; chiasma; genetic variation;
(Meiosis) metaphase I: the tetrads … at the … of the cell
The way this occurs gives each cell a unique combination of genes from each parent’s chromosomes (an …).
Along with crossing over, these methods account for most of the genetic variation in populations
line up; equator; independent assortment
(Meiosis) independent assortment: given n pairs of chromosomes, there are … ways in which chromosomes can line up during metaphase I.
In humans there are … (.. million) ways of combining homologues. This means combining human gametes can produce .. combinations in the zygote
Mendel’s law of …
2^n; 2^n; 8; 64 trillion; assortment
(Meiosis) anaphase I: the tetrad ..,maternally and paternally inherited chromsomes moving to .. or the other, independent of the other chromsomes. .. remain attached
splits; one pole; sister chromatids
(Meiosis) telophase I: .. reforms, nucleus is now …
interkinesis: .. of the …, similar to…
nuclear envelope; haploid; division; cytoplasm; cytokinesis
(Meiosis) meiosis II
prophase II: … disappears; … forms
metaphase II: chromosomes with … sister chromatids ..
anaphse II: .. split apart, one … moving to each pole
telophase II: … reappears
cytokinesis: … divide
daughter cells are …
nuclear envelope; spindle; 2; line up at the equator; chromosomes; chromatid; nuclear envelope; cytoplasm; genetically identical
(Meiosis) … is the failure of chromsome pairs to .. either during … or … –> either homologues/sister chromatids
nondisjunction; separate; meiosis I; meiosis II
(Meiosis) fertilization of an egg resulting from nondisjuction with a normal sperm results in a zygote with an … —> can lead to … or …
cases where offspring is born:
Turner’s (…) —> … chromosomes
Down syndrome –> … chromosomes
kleinfelter’s —> … chromsomes
only … involves less chromosomes than normal
abnormal chromosome number; miscarriage; spontaneous abortion; XO; 45; 47; 47; Turner’s
(Meiosis) In most cases, human offspring which develop from zygotes with incorrect numbers of chromosomes … This is one reason for the large number of miscarriages which happen during the first trimester of pregnancy.
There are two main types of alterations: … and …
abort spontaneously; aneuploid; polyploidy
(Meiosis) aneuploidy occurs when a gamete which has undergone a faulty meiosis and has an abornmal number of chromsomes unites with a ..or … The zygote formed will have an abnormal number of …
in a trisomy, the zygote has an … of a chromsome (e.g. down syndrome, kleinfelters)
if the zygote is missing a chromosome, it is called a … (e.g. Turner’s)
normal egg; sperm; chromosomes; extra copy; monosomy
(Meiosis) trisomy 21- Down syndrome
trisomy 21 is the most common chromosome-number abnromality with 3 copies of … It occurs in 1 out of 700 births.
Incidence of Down Syndrome increases with … of the mother
Down syndrome (common name for Trisomy 21) includes a wide variety of …, …, and … features
(the incidence rate also increases with the … of the father)
chromosome 21; age; physical; mental; disease-susceptibility; age
(Meiosis) people with down syndrome are likely to have …, … (skin s very …), … disease, … rapidly
diabetes; skin disorders; thick; heart; age
(Meiosis) unusual numbers of sex chromosomes (those that determine sex, such as X, Y) do not upset the genetic balance as much as unusual numbers of … (all other chromosomes)- perhaps due to the fact that Y chromosome carries ..
abnormalities in sex chromosomes result in individuals with a variety of characteristics, the most seriously affecting … and …
the greater the number of … chromosomes, the greater likelihood for mental retardation
autosomes; fewer genes; fertility intelligence; X
(Meiosis) sex chromsome abnormalities illustrate the role of the .. chromosomes in determining a person’s sex
a single Y chromosome is enough to produce “…” even in combination with a number of X chromsomes (e.g. Klinefelter’s – …)
the lack of a second X or Y chromosome will still result in “…” due to the presence of X chromsome (e.g. Turner’s)
Y; maleness; XXY; femaleness
(Meiosis) polyploidy is lethal in humans. it occurs when an organism has extra …
polyploidy isnormal in … and is sometimes normal for completion of certain stages in their life cycle.
full sets of chromosomes; plants
(Meiosis) polyploid plants tend to be … and better at … in …
larger; succeeding; farm fields
(fertilization & development) although all species pass their alleles to their offspring, the way in which they are passed varies. Some different ways include:
…, …, …, …
the first three are considered … reproduction because they don’t involve … from more than one individual
fission; budding; fragmentation; sexual reproduction; asexual; mixing genes
(fertilization & development) fision is when the parent organism … into “…” organisms. In other words the parent … and is … by its offspring.
splits; daughter; ceases to exist; replaced
(fertilization & development) bacteria divide by .. one parent splits into two offspring. the parent’s genes are … and one copy is given to each of the of offspring
binary fission; copied
(fertilization & development) budding is when a few cells from a parent organism grow into an … this happens mostly in .., .., or simple … such as the …
adult offspring; plants; unicellular organisms; animals; hydra
(fertilization & development) fragmentation passes alleles from parent to offspring by … it is different from budding because the offspring begins to grow from a … of the parent that has been …
breaking a piece off of the parent; piece; removed
(fertilization & development) fragmentation
starfish can produce offspring by removal of an .. the parent will grow back the .. and the offspring will grow a body from that arm
… of starfish (…) allows for this
arm; removed arm; central disk; brain
(sexual reproduction) sexual reproduction is unique to the other forms for several reasons:
it requires .., one … and one …
genes from the participants are …
each parent contributes … their genes to the offspring.
each offspring is … from its parents and its siblings, with the exception of …
requires either … or …
may utilize chemical signals known as …
this process is considerably more complex, burns valuable … and requires elaborate .. in many species
2 individuals; male; female; mixed together; half; genetically unique; identical twins; external; internal fertilization; pheromones; energy; mating rituals
(sexual reproduction) asexual organisms can:
reproduce ..
pass .. their genes to their offspring (not half)
produce offspring with no need to ..
spend … producing sex cells (egg/sperm)
faster; all; find a mate; no energy
(sexual reproduction) the process of sexual maturity, like most processes of growth and development is directed and maintained by … two main hormones govern sexual maturity, although many other hormones play a lesser role.
… is a lipid hormone that generally promotes the maintenace of female sexual characteristics
.. is a lipid hormone that generally promotes the maintenace of male sexual characteristics.
sexual maturation begins at puberty in the … and … of the brain with the release of … (..)
hormones; estrogen; testosterone; hypothalamus; pituitary glands; gonadotropin-releasing hormone; GnRH
(sexual reproduction) GnRH (proteinaceous) intiates the release of … (…) and … (…) from the pituitary. These hormones initate different cellular responses in males and females.
follicle-stimulating hormone; FSH; luteinizing hormone; LH
(sexual reproduction) FSH in males stimulates the testes to .. , in females regulates development of the … and secretion of … by the …
produce sperm; follice; estrogen; follicle
(sexual reproduction) LH in males stimulates … secretion, and in females stimulates … secretion
testosterone; estrogen
(sexual reproduction) female reproductive system:
ovaries: female …; produce . (…)
fallopian tubes: not connected to …, … occurs here; paired .. leading from each ovary to the …
uterus (…): .. organ; … will develop inside the uterus
cervix: opening of the …, will constrict during … and … in preparation for birth
vagina: passage way to …; receives …; also ..
gonads; ova; eggs; ovaries; fertilization; tubes; uterus; womb; muscular; fetus; uterus; fetal development; dilate; uterus; sperm; birth canal
(sexual reproduction) oogenesis is the development of female … or … the development of ova occurs in females while they are still in … ovaries in the female fetus begin to develop … (the precursors to ..) but development of ova is halted at … until …
gametes; ova; their mother’s womb; oogonia; ova; meiosis I; puberty
(sexual reproduction) at puberty, meiosis resumes generating 1 … and 3 … for each cell undergoing meiosis. In humans, 1 or 2 eggs will mature approximately every … days
haploid cell; basal bodies; 28
(sexual reproduction) each primary cell divides … the divisions produce only one … and three …
twice; mature ovum; polar bodies
(sexual reproduction) polar bodies normally … and contain less cytoplasm than ova. ova is what will be combined with sperm to produce offspring
disintegrate
(sexual reproduction) in humans, the process of ovulation (releasing an …) the thickening of the … in preparation for an … is knwon as … or the …
ovum; uterine walls; embryo; menstruation; menstrual cycle
(sexual reproduction) male reproductive system:
testes (contained in …): male …; produce …
epididymis/ Vas deferens: tubes leading from the … to the …; store …
epididymis is .., to increase …
sperm enters the … when matured
vas deferens pass through …
urethra: pathway for … and … although not at the same time
penis: male … organ; deposits .. inside the female
seminal vesicles/prostrate gland/bulbourethral glands: … organs which produce … to nourish and protect …; combination of … and … is termed semen
scrotum; gonads; sperm; testes; urethra; sperm; coiled; SA; vas deferens; abdominal cavity; sperm; urine; reproductive; sperm; accessory ; fluids; sperm; sperm; fluids
(sexual reproduction) spermatogenesis is the development of … or … Spermatogenesis begins at … and generally continues for the … of the male. Mature sperm are the only human cells capable of … (they have …)
Sperm are “stripped down” to the basic essentials for a cell. They contain only a …, …, a …, and … to dissolve the protective coating of the … cell
male gametes; sperm; puberty; life; motility; flagella; nucleus; mitochondria; protein coating; enzymes; egg
(sexual reproduction) each primary cell for spermatogenesis divides .. The divisions produce ..
primary cell –> secondary cell –> .. –> …
twice; 4 mature sperm; spermatid; sperm
(sexual reproduction) in humans when an ovum has been fertilized, the genetic makeup of the .. determines the sex of the embryo. human ova contain only … as the 23rd chromosome. human sperm can have either an .. or a … chromosome. thus, the default state of a human embryo is … the … chromosome contains a number of genes that code for various proteins which induce male development and fertility
sperm; X chromosomes; X; Y; female; Y
(sexual reproduction) fertilization occurs when one sperm and one ovum unit their individual … and return the organism to its … state
DNA; diploid
(sexual reproduction) aquatic animals usually utilize .. In this type of fertilization, both sperm and eggs are … in large numbers into …
external fertilization; released; water
(sexual reproduction) humans, mammals, and most other land animals utilize …: sperm are deposited … the body of the female.
In in vitro fertilization, sperm and ovum are united in a … under .. conditions
internal fertilization; inside; laboratory; sterile
(sexual reproduction) as sperm approach an egg, several begin to .. through the protective coatings (…) but only one will be able to .. the egg. This process consists of the .. int he sperm and the … in the egg
burrow; zona pellucida; fertilize; acrosome reaction; cortical reaction
(sexual reproduction) acrosome reaction (sperm): the enzyme in the … of each sperm cell are released to breakdown the …. of the egg. once one spermcell reaches the plasma membrane of the egg, its nucleus and DNA is.. into the egg cell. immediately the … occurs
acrosome; protective coverings; released; cortical reaction
(sexual reproduction) cortical reaction (egg): once one sperm has penetrated the egg, a number of … and … occur within the egg to … the plasma membrane and ensure no other sperm are allowed to enter
biochemical; electrical; fuse;
(sexual reproduction) electrical reactions for cortical reaction entails influx of … and changes …
Ca2+; electrochemical gradient
(genetics of development) the most difficult task for the genes of a multicelled complex organism is to develop the organism from a
single cell
(genetics of development) development is a process where the products of some genes turn other genes … or … Even before fertilization, this is occurring. the egg supplies information to establish a … this system provides a way of determining which future cells will become differentiated into … of the organism
on; off; molecular coordinate system; certain parts
(genetics of development) the nuclei of the sperm and the nuclei of the egg are termed
pronuclei
(genetics of development) after fertilization, the nuclear membrane of each pronuclei … and homologus chromosomes .. the cell is stimulated to begin a number of …
… is occurring here
degenerates; pair together; mitotic divisions; selection
(genetics of development) twins can occur either when:
more than one egg is .. and … at the same time (… twins/ … twins)
one of the first few divisions completely separates into … or … (… twins/ … twins)
frathernal twins have a … placenta, while identical twins have a … placenta
released; fertilized; fraternal; dizygotic; two separate cells; cell masses; identical; monozygotic; separate; shared
(genetics of development) basics of human deveopment
day 0: …
day 1-4: .. cell … (do not include all stages of .. –> no …)
day 4-5: … (ball of …) stage
day 5-6: … ball; … stage. characterized by a … which forms in the center while at the same time cells …, migrate to …, and differentiate into …
Day 6-9: embryo now .. into uterus, and the … forms
Day 13-15: … the cell layers fold … forming three … (…, …, and …)
day 15-21: the … cells multiply, and migrate along the … (…) side of the embryo –> … tube (…)
fertilzation; mitotic cell divisions; interphase; growth; morula; cells; hollow; blastocyst; cavity; flatten; one side; basic cell types; implants; placenta; gastrulation; inward; distinct layers; ectoderm; mesoderm; endoderm; ectodermal; dorsal; back; neural; spinal cord
(genetics of development) zygote doesn’t change shape/size until after .. stage
zygote and … are same size, but … is made up of …
afte rmorula stage, cell becomes …
morula; morula; morula; many cells; larger
(genetics of development) the three germ layers (gastrulation)
- ectodermal cells next … themselves into a neural … and neural … which … and then fold … forming the ..
- the neural tube will eventually form the … consisting of the …, …, and … other ectodermal tissues form the …, outer … of … and the outer … of …
the mesoderm will give rise to the .., most …, and the inner … of the …
the endoderm will give rise to the … and … systems
align; groove; plate; thicken; inward; neural tube; nervous system; brain; spinal cord; nerves; sensory organs; linings; organs; layer; skin; muscles; internal organs; layers; skin; respiratory; digestive
(genetics of development) stem cells are … cells- cells that have not decided what type of cell to become. scientific research has investigated the use of stem cells to treat various human diseases. bone marrow transplants have for many years isolated … from …
stem cells can also be isolated from the ..; these are termed … stem cells can be isolated and removed from discarded …
cells isolated from the three germ layers are termed .. stem cell research using these stem cells has been impeded by moral questions and the tendency of these cells to divide ..
undifferentiated; adult stem cells; bone marrow; umbilical cord; umbilical stem cells; human embryos; embryonic; unpredictably
(genetics of development) one of the best understood examples of molecular coordination in development is the patterning along the future … and … of the fruit fly, Drosophilia melanogaster. These are fundamental genes that give way to the developmental structure of the fly. The genes that are involved are: … and …
anterior; posterior; maternal effect genes; homeotic genes
(genetics of development) before a fruit fly egg is fertlized, genes are being … one of those genes is known as the … gene. this maternal effect gene produces … that float in the cytoplasm. Its uneven distribution (due to the location of the …) creates a gradient
expressed; bicoid; RNA molecules; nucleus
(genetics of development) bicoid diffuses from … to .. and is most concentrated at ..
anterior; posterior; anterior
(genetics of development) after the egg is fertilized it begins to divide by … but there is no increase in the amount of … as these first quick divisions occur. each of these new stem cells contains a slightly different concentration of bicoid RNA
this process of keeping size but division occurring is …
mitosis; cytoplasm; cleavage
(genetics of development) this coordinate system provides a way of determining which end is … or … the cells with high bicoid concentration will activate genes for tissues in the … of the organism. Decreasing amounts lead to the proper order of … and very low will become the …
posterior; anterior; head; segments; tail
(genetics of development) similar gradients will also determine … and … of the developing fly more bicoid is at the … side
dorsal; ventral; ventral
(genetics of development) the unique concentration of several maternal effect gene products ensures each cell in the eveloping embryo has different … and ..
transcription factors; gene expression
(genetics of development) recall that before cells become differentiated into their specific type, they are a stem cell. these contain the entire .. of the organism but have not received the … needed to become a specific type of cell. bicoid concentration is the first step in a … of reactions that result in the … into …
genome; signals; cascade; transformation of stem cells; specialized cells
(genetics of development) maternal effect genes act as …, turning other genes on or off, and as a result, formed the segmented pattern of the fruit fly. the homeotic genes, having been turned on or off by he cascade of gene expression started by the maternal effect genes, also produce .. they influence the expression of numerous other genes and determine the … of the segment they are in
transcription factors; transcription factors; identity
(genetics of development) it has been found that the sequence of homeotic genes in fruit flies known as the … genes are lined up in exactly the same order as the … they affect. the first gene affects the mouth, the second the face, the third the top of the head, and so on up until the eighth and final gene that affects the abdomen
hox; part of the fly
(genetics of development) the proteins that Hox genes produce determine the type of … such as legs, antennae, and wings in fruit flies or the different vertebrae ribs in humans
segment structures
