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BIO355
Genetics
31
Biology
Undergraduate 4
03/12/2012

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Term
Outcomes of meiosis vs mitosis (types of cells)
Definition
the outcome of meiosis is four (genetically unique) haploid (1N) cells, compared with the two (genetically identical) diploid (2N) cells produced from mitosis
Term
Interphase
Definition
process that occurs before meiosis, 3 stages: gap one where proteins are made, organelles are copied and proteins replicated, cell growth (checkpoint- controlled by gatekeeper genes, w/o appropriate signal, cell goes into gap 0), synthesis is where the DNA replicates, and gap 2; same as mitosis, make more cytoplasm
Term
Goal of Meiosis
Definition

goal is to half the # of chromosomes in each cell

 (per cell- 46-->23 chromosomes)[image]

Term
Prophase I
Definition

Pairing btw homologous cs; forms tetrad (4 Chromatids)

nuclear membrane dissolves, centriole pairs split, every replicated cs will have one centromere and will condense

[image]

Term
chiasmata
Definition
point of intermingling btw nonsister ct on homologous cs, allows crossing over
Term
crossing over
Definition
occurs during prophase I, Crossing-over is the process that can give rise to genetic recombination ( a molecule of nucleic acid is broken and then joined to a different one), physical exchange of cs parts, exchange btw homologous cs
Term
Metaphase I
Definition
Need spindle fibers to attach to centromere before can start, independent assortment,The centrioles are at opposite poles of the cell.

Term
Mendels law of independent assortment
Definition
cs pair aligns at equator independent of ALL other cs pairs
Term
Anaphase I
Definition
Law of Segregation, "like" genes on homologous cs seperate during gamete formation, the sister chromatids remain attached at their centromeres and move together toward the poles. A key difference between mitosis and meiosis is that sister chromatids remain joined after metaphase in meiosis I, whereas in mitosis they separate.
[image]
Term
telophase I
Definition
replicated cs moved to the poles,The homologous chromosome pairs complete their migration to the two poles as a result of the action of the spindle. Now a haploid set of chromosomes is at each pole, with each chromosome still having two chromatids.

• A nuclear envelope reforms around each chromosome set, the spindle disappears, and cytokinesis follows
Term
cytokinesis
Definition
cytoplasm divides, forming 2 cells each with 23 repliaced cs
Term
interkinesis
Definition
resting time btw meiosis I and II,
Term
Meiosis II
Definition
Ct of each replicated cs seperate; forming haploid cells, similar cs movement as mitosis except half the diploid # of cs (23cs)
Term
prophase II
Definition
replicated cs condense (2 sister ct joined by a centromere), microtubules attach to the cs, spindle fibers attach
Term
metaphase II
Definition
23 Unpaired cs attach to spindle fibers at centromere and pushed to equator
Term
anaphase II
Definition
Ct on replicated cs seperate each becoming a cs, centromeres seperate
Term
telophase II
Definition
Cs decondense (same as Meiosis I), Nuclear membrane forms, genetic material at the poles, 46 unrepliacted cs in cell (23 at each end)
Term
4 ways male gamete development differs from female development
Definition

1) amount of gametes- males continuously produce new sperm,  The production of one egg cell via oogenesis normally occurs only once a month, from puberty to menopause.

2)oogenesis only leads to the production of one final ovum, or egg cell, from each primary oocyte (in contrast to the four sperm that are generated from every spermatogonium)

3) Meiosis II is completed in females only upon fertilization vs. males produce spermatids after meiosis II regaurdless

4) males start process at puberty vs females start at birth (born with amount of primary oocytes) 

 

 

 

 

Term
Difference btw homologus cs and sister ct
Definition
Sister chromatids are two identical copies of a chromatid connected by a centromere. Compare sister chromatids to homologous chromosomes, which are the two different copies of the same chromosome that diploid organisms (like humans) inherit, one from each parent. In other words, sister chromatids contain the same genes and same alleles, and homologous chromosomes contain the same genes but two copies of alleles, each of which might or might not be the same as each other.
Term
genotype
Definition
two allelic forms (one from mom and one from dad) of a specific gene in a person
Term
phenotype
Definition
observed expression of a particular trait
Term
How inheritance is determined in humans
Definition
pedigree analysis
Term
determines potential gametes
Definition
fork-line method (take multiple traits that can be discerned and make multiple gametes)
Term
Determines potential offspring
Definition
punnett square (can see how many times have a certain phenotype)
Term
Huntingtons Disease
Definition
Disruption of brain chemistry, muscular twitching, chorea(abnormal involuntary movement), emotional distrubances-->demetia (phenotypic expession similar to Alzheimers), cant do purposeful motions, make protein and cant be broken down in dominant allele, basal ganglia destroyed, more then 36 CAG repeats means + for Huntingtons Disease
Term
porphyria
Definition
can not metabolize Heme, a product of RBC breakdown, causes neurological problems like mental breakdown heme accumulates-->causing hyperaccumulation, organs can build heme causing problems
Term
Marfan Syndrome
Definition
defects in fibrillin, a gylcoprotein of connective tissue, affects eye lens, long bones,aorta (suspectible to weakness in aortic arch, causing an aneurysm), can occur from a new mutattion (de novo)
Term
Neurofibromatosis
Definition
benign tumors on the nervous system, may be caused de novo, may appear as cafe au lait spots, without tumors,  if only one parent has neurofibromatosis, his or her children have a 50% chance of developing the condition as well.
Term
Proteus Syndrome
Definition
Genetic defect, tumors, can deform the bone, congenital disorder that causes skin overgrowth and atypical bone development, often accompanied by tumors over half the body
Term
achondroplasia
Definition
(Dd) genetic dwarfism (disportionate), can be caused de novo, (DD) homozygous dominant is lethal(sponatenously aborts)
Term
2 ways of coding for MOST genes
Definition
dominant and recessive alleles, can distinguish via phenotypic effects
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