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Definition
| Orderly set of stages between cell division and the next cell division. This includes Interphase and Mitosis |
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Definition
-Majority of Cell cycle (90%)
-Cell performs usual functions
-varies from few hours in embryos to 20 hours in adults
-NOT resting, VERY busy |
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Definition
Growth prior to DNA replication
Recovery from previous division
increased in size, doubles organelles & acquires material for DNA replication
Nerve and Muscle cells instead enter G0 because they do not replicate |
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Definition
DNA synthesis
-starts w/ 1 DNA 2x helix and ends with 2 DNA 2x helix |
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Each DNA double helix (the replicated copies are known as sister chromatids)
Sister chromatids are identical chromosomes attached at centromere |
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Completion of DNA Replication
Initiates Mitosis
synthesis of proteins to assist cell division (microtubules for example) |
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Definition
| Nuclear division of a cell into two identical daughter cells |
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Definition
| Division of the cytoplasm |
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Definition
Interphase (G1, S, G2)
Mitosis (Propase, metaphase, anaphase, telophase)
Cytokinesis |
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Term
| Control of the Cell cycle |
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Definition
cell cycle checkpoints the primary one is G1 checkpoint but G2 checkpoint will stop cell division if DNA isn't done replicating or if cell is in need of repair before M
Cell stops in M phase checkpoint if chromosomes are not properly attached to mitotic spindle |
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Definition
internal signaling proteins that control cell cycle
-P53 is a cyclin that stops cell cycle at G1 checkpoint if DNA is damaged. It attempts to initiate cell repair but if levels are high than it initiates apoptosis |
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Definition
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Definition
| protein responsible for interpreting growth signals and nutrient availability |
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Definition
| cells round up and disengage form neighboring cells (lose contact), nucleus breaks down and PM blisters then fragments are engulfed by WBC through phagocytosis |
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Definition
| enzymes that cause apoptosis; they are always in cell but are inhibited unless activated by p53 |
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| apoptosis and cell division |
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Definition
opposing systems that keep cell # in check for somatic cells
both are normal parts of growth and development
limits cancer and spread of virsuses |
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Definition
-associated with histones (proteins involved in organizing chromosomes)
-When cell isn't dividing DNA is in chromatin but it condenses before mitosis
-diplod=2n and haploid=n |
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Term
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Definition
Chromosome duplication (during S stage)
Division of centrosome |
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Term
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Definition
| protein complexes that develop on either side of centromere |
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Definition
main microtubule organizing center of cell
in animal cells contains pair of barrel-shaped organelles called centrioles
job is to organize mitotic spindle(which is many fibers, microtubules composed of tubulin) |
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Definition
-chromatin condensed
-nucleolus disappears and and nuclear envelope fragments
-spindle begins to assemble and centromeres distance themselves
-asters develop (array of microtubules that aerve to brace centrioles) |
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Term
| Prometaphase (late prophase) |
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Definition
-prep for sister chromatid seperation
-kinetochores are on each side of centromere and attach to spindle fibers
-chromosomes pulled from one pole to another and begin to align |
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Definition
-centromeres align on center of cell
-metaphase plate=imaginary line where they align=future axis of division
-polar spindle fibers pass metaphase plate |
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Definition
-shortest phase
-separation of chromatids @ centromere
-start to move toward opposite poles
-kinetochore and spindle fibers begin to disassemble at centromere
-kinesin & dyein involved in sliding process |
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Definition
-spindle fibers disappear
-new nuclear envelope forms
-remnants of polar spindle fibers still present
-chromosomes become diffuse chromatin again |
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Term
| Cytokinesis in Animal and Plant Cells |
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Definition
-if cytokinesis does not occur and mitosis does it results in a multinucleate cell
-division of cytoplasm is in anaphase, telophase and interphase
in animal cells there is the cleavage furrow (indent in membrane) and in plant cells cell plate forms and cell wall grows |
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Term
| More details on cleavage furrow |
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Definition
| just as anaphase is ending it appears and then deepens when a band of actin filaments (contractile ring) slowly forms a circular constriction between cells |
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Definition
permits growth and repair
meristematic tissue in plants allows it to keep growing (think roots)
stem cells=retain ability to divide (red bone marrow cells)
therapeutic cloning is used to produce human tissues and there is also reproductive cloning |
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Definition
| cellular growth disorder when cells divide uncontrollably |
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| Characteristics of Cancer cells |
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Definition
-gradual development (pre-cancerous to cancerous)
1. lack differentiation-not specialized and don't contribute any function
2. Abnormal nuclei-enlarged and abnormal # of chromosomes, some may have deleted portions
3. Don't undergo apoptosis
4. Form tumors=no contact inhibition
5. Metastasis and angiogenesis=tumor within capsule that can't be invaded by adjacent tissue
metastasis=spread out forming new tumors
angiogenesis=blood vessel formation for nutrients to cancer cells |
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Definition
| code for proteins to promote cell cycle and prevent apoptosis |
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Term
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Definition
| code for proteins that inhibit cell cycle and promote apoptosis |
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Term
| Proto-oncogenes become oncogenes |
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Definition
Proto-oncogenes extend from PM to nucleus. include receptors and signal molecules that make up pathway
When mutations occur they become oncogenes (uncontrolled cell division ensues)
there are 100 oncogenes in human cells and most belong to RAS family |
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Term
| Tumor Suppressor genes become inactive |
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Definition
-tumor suppressor genes which inhibit cell cycle and prevent cell division are turned off.
There are 6 tumor suppressor genes (RB and p53 are included)
-1/2 of cancers are caused by abnormal or deleted p53 gene
other causes are mutation of enzyme that regulates telomeres |
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Term
| Prokaryotic cell division |
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Definition
| involves duplication of single chromosome that results in 2 new individuals=asexual reproduction |
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Term
| the prokaryotic (bacteria and archaea) chromosome |
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Definition
dont have a nucleus but do have 1 chromosome and the associated proteins (many less though)
chromosome appears as nucleiod and is a circular loop 1000x's length of cell |
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Definition
| cell enlarges, DNA replication, chromosomes attach to PM and seperate by cell elongation. New PM and cell wall grow inward to help cell divide. E. COli only take 20 min (1 million cells in 7 hours) |
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Term
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Definition
both produce 2 genetically identical daughter cells
proK produce 2 whole individuals while euK use it for repair, renewal and growth
-in euK histones allow chromatin in interphase and coil in mitosis
-spindle involved in distributing chromosomes in EuK, not in BF |
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Definition
| type of nuclear division that reduces the crhomosome # by 1/2 |
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Definition
| reproductive cells that have haploid chromosome # |
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Term
| Homologous pairs of chromosomes |
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Definition
| look alike, same length and centromere position, similar banding pattern |
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| alternative form of a gene |
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Definition
-requires 2 nuclear divisions and produces 4 haploid daughter cells w/ 1 of each kind of chromosome
-the daughter cells are not genetically identical to each other nor the parent cell
-Dna replication occurs prior to meiosis I
-During meiosis I homologs come together and align side by side (synapsis) and result in bivalent chromosomes (tetrads)
-following synapsis, homologues align at metaphase plate and members seperate
-during meiosis II, sister chromatids seperate and go to poles
-at end of meiosis II, sister chromatids separate and each cell has a single chromatid |
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Term
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Definition
-plants=haploid spores germinate and produce gametocytes by mitosis
-animal=daughter become gametes and then they combine to form zygote |
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Term
| How does meiosis ensure genetic variation? |
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Definition
| crossing over and independent assortment |
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Term
| Genetic recombination (Crossing Over only) |
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Definition
-crossing voer=exchange of genetic material between non-sister chromatids during meiosis I. 2 or 3 exchanges per chromosome
-at synapsis homologues line-up side by side and a nucleoprotein lattice appears between them ensuring correct alignment of genes
-as lattice breaks down, chiasmata hold the pair together
-crossing over recombines alleles resulting in different offspring |
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Term
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Definition
| homologous chromosome pairs separate independently and in a random manner |
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| Significance of Genetic Variation |
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Definition
Humans= over 8 million combinations of gametes from 1 person
-enhanced by fertilization 70 trillion combinations w/o crossing over |
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Term
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Definition
| -prep for nuclear division, spindle forms, centrosomes migrate away from each other, nuclear envelope and nucleolus dissolve, synapsis forms bivalents, crossing over, gradual condensing of chromosomes |
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Term
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Definition
| bivalents move to metaphase plate, kinetochores seen, bivalents independently align |
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Term
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Definition
| -prep for nuclear division, spindle forms, centrosomes migrate away from each other, nuclear envelope and nucleolus dissolve, synapsis forms bivalents, crossing over, gradual condensing of chromosomes |
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Definition
| homologues separate and move to opposite poles but sister chromatids remain attached to each other |
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Definition
| not necessary during meiosis (spindle disappears but new nuclear envelopes do not need to be formed. |
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Term
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Definition
| similar to interphase but no DNA replication |
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Term
| Meiosis II and gamete formation |
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Definition
-starts w/ 2 daughter cells w/ haploid # of chromosomes
-metaphase II=chromosomes align at metaphase plate
-anaphase II=sister chromatids separate becoming daughter chromosomes that aren't duplicated
-at end of telophase II and cytokinesis there are 4 haploid daughter cells
-alternation of generations=plant cells that are haploid spores that become diploid and back to haploid |
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Term
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Definition
Meiosis=2 nuclear divisions, Mitosis=1
haploid (half or parents), diploid (same as rents)
no genetically identical, genetically identical to each other and rents
only certain times in life cycle of sexually reproducing organisms, more common b/c it occurs in all tissues for growth and repair |
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Definition
crossing over only prophase I
independent alignment is only metaphase I
bivalents separate in anaphase I |
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Definition
| nuclei contain haploid # and produces total of 4 in meiosis II |
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Definition
| all reproductive events that occur from one generation to the next similar generation in plants (includes alteration between diploid and haploid generations) |
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| Haploid and Diploid names in plants |
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Definition
haploid=gametophyte
diploid=sporophyte |
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Definition
| in testes, stem cells as spermatogonia turn into primary spermatocytes then meosis I turns into secondary spermatocytes and then 4 spermatids and then spermatozoa |
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Definition
| in ovaries, stem cells are oogonia then primary oocyctes then meiosis I=secondary oocyte and polar body and then meiosis II than stops ar metaphase II . It either disintegrates or is fertilized where meiosis II is resumed and forms second polar body |
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| Types of changes in chromosome # |
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Definition
| reult in aneuploidy including monosomy, trisomy, |
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Definition
| change in correct number (euploidy) of chromosomes due to nondisjunction |
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Definition
2n-1
when only 1 chromosome of pair is present |
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Term
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Definition
| (2n+1)= 3 of a type of chromosome |
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Definition
| both homologous chromosomes go into same cell |
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Definition
| meiosis II when sister chromatids go into same gamete in humans only viable for chromosome 13,18,21 |
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Definition
trisomy 21
-short stature, eyelid fold, flat (moon) face, stubby fingers, gap between toes, large tongue, round head, palm crease, heart problems and mental retardation |
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Term
| Nondisjuntion in sex chromosomes |
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Definition
XO=turners syndrome female, short, broad chest, far apart nipples, neck webbing, underdeveloped female parts
XXY=Klinefelter male, testes underdeveloped, giant hands and feet
Poly X female=tendency to be tall and thin (usually fine)
Sawyer=XY female (no SRY gene)
de Lachapelle sydrome=XX w/ SRy male
Jacobs syndrome (XYY) tall w/ acne & learning disabilities |
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Term
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Definition
| extra non-functioning chromosome |
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| Changes in chromosome structure |
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Definition
| may be caused by radiation, viruses, chemicals |
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Definition
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Definition
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Definition
| 180 degree rotation of segment |
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Definition
| movement of segment from 1 chromosome to an unrelated one |
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Definition
| deletion of end of chromosome #7. turned up noses, wide mouths, large ears |
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Definition
| chromosome #5 missing end, mentally retarded and facial abnormalities |
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Definition
| explain stability and variations of inheritance for agriculture, breeding and medicine |
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| Blending concept of inheritance |
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Definition
| outdated and disproved by mendel, this theory said that the offspring's traits would be intermediate of parents |
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| Mendel's particulate theory of inheritance |
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Definition
| reshuffling of same genes from generation to generation |
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| Mendel...why garden peas? |
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Definition
| easy to cultivate, short generation time, cross pollination by hand but otherwise true breeding, many varieties, simple and discrete traits, no intermediate traits |
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Term
| Mendel's Law of Segregation |
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Definition
| each individual has 2 factors for each trait, the factors segregate during formation of gametes, each gamete contains only 1 factor from each parent's pairs, fertilization gives each new individual 2 factors for each trait |
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| Mendel's conclusion regarding monohybrid crosses |
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Definition
| 3:1 ratio phenotypically, 1:2:1 genotypically |
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| Mendel's cross as viewed by classical genetics |
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Definition
gene locus=particular location where gene occurs
alleles=alternative versions of a gene
dominant=masker
recessive=not expressed except for in absence of dominant
homozygous=2 identical alleles
heterozygous=2 different alleles
genotype=alleles an individual receives
phenotype=physical appearance of individual |
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Term
| Mendel's law of independent assortment (dihybrid cross that resulted in 9:3:3:1) |
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Definition
| each pair of factors segregates independently of other pairs, all possible combinations of factors can occur in the gametes BUT applies only to alleles on diff. chromosomes |
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| Mendel's Law and Human genetic disorders |
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Definition
| autosome=any chromosome other than a sex chromosome, autosomal patterns of inheritance, carriers=appear normal but may have a child with the disorder |
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| Autosomal recessive disorders |
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Definition
| most affected children have unaffected parents, heterozygotes are unaffected, 2 affected parents always have affected child, close relatives that reproduce are far more likely to have affected children |
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| Autosomal dominant disorders |
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Definition
| Affected children usually have affected parent, heterozygotes are affected, 2 affected parents could produce unaffected child, 2 unaffected parents cannot have affected child |
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Definition
| autosomal recessive disorder, relatively harmless, accumulation of methemoglobin in blood, blueish purple skin, lack enzyme diaphorase, chromosome 22 |
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Definition
| autosomal recessive, most common lethal genetic disease in caucasians in US, 1 in 20 white americans is a carrier, 1 in 2000 newborns has the disorder, extremely salty sweat, think mucous interferes w/ function of lungs and pancreas, mucous must be broken up by patting and enzyme consumption, defective Cl- channel that is encoded by CFTR allele on chromosome 7 |
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Definition
| autosomal recessive disorder, infants w/ jaundice feeding difficulties enlarged abdomen and mental retardation, type A and B caused by defective versions of gene on chromosome 11, codes for the enzyme that breaks down lipid sphingomyelinase so the lipid accumulates in liver, lymph nodes, spleen and brain |
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Definition
| autosomal dominant, brittle bone disease (9 types), 1 in 5,000 live births, linked to 2 genes necessary for collagen synthesis, treatable w/ bone mass increasing drugs, blue tint to eye white, reduced skin elasticity, weakened teeth, heart valve abnormalities |
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Definition
| autosomal dominant, defective copy of ankyrin-1, gene on chromosome 8, RBC form spherical shapes (fragile and burst easily), 25% result from new mutation and may be cases of incomplete penetrance |
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| Multiple Allelic Traits-cases of co-dominance |
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Definition
| blood types for example, A and B can both be present |
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Definition
| heterozygote has an intermediate phenotype such as hypercholesterolemia (HF) |
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Definition
| Dominant allele not leading to dominant phenotype, polydactyly (may only have 1 extra digit) |
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Definition
| single mutant gene affects 2 or more distinct and "unrelated" traits. Marfan syndrome is example: abnormal connective tissue leads to long arms and legs, weakened aorta, poor eye sight yet all caused by mutated gene (FBN) on chromosome 15 which codes for fibrillin |
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Definition
| another example of pleiotropy, chemical inefficiency in production of hemoglobin, photosensitivity, abdominal pain, wine-colored urine, paralysis |
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| trait governed by 2+ sets of alleles, multifactorial traits controlled by polygenes subject to environmental influences, skin tone, height, eye color, also cleft lip, club foot, congenital dislocation of hip, hypertension, diabetes, schizophrenia, allergies and cancers |
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Definition
| discovered through Morgan's experiment w/ Drosophilia melanogaster . Red and white eyes...noticed more affected males, males are hemizygous for X-linked traits, only 1 allele for trait |
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| Color-blindness and male pattern baldness |
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Definition
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Definition
| kinky hair due to accumulation of copper in some parts of body and lack in other parts, poor muscle tone, seizures, low body temp, skeletal anomolies, steely hair, die in first years of life |
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Definition
| duchane is X-linked, wasting away of voluntary muscles, 1 out of 3,600 male births, toe walking, frequent falls, due to absence of dystrophin protein |
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Definition
| x-linked, ALD, failure of carrier protein to move enzyme into peroxisome so fatty acids aren't broken down, accumulate in cells, damage nerve cells, adrenal glands don't function, poor circulation, progressive loss of hearing, vision, speech |
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Definition
| A is due to absence of clotting factor VII, B is due to IX, must be given plasma transfusions or concentrates fo clotting factor proteins |
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