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105 Cards in this Set
- Front
- Back
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The inactivation of the X chromosome is called a?
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Barr body
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Barr bodies result in cells that have either and active or inactive x chromosome. This is called a ____ of expressivity.
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Mosaic
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Examples for mosaicism in females from class are?
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sweat spots
R/G color blindness calico cats |
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T or F?
A women expresses both X when she is conceived? |
True
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T or F?
All daughter cells of the cell with the barr body will express different x chromosomes? |
False
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T or F?
Not all individuals need an X chromosome to survive? |
False
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How is sex-linked different than sex-influenced traits?
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Sex-linked traits can only occur in that sex and occur on the sex chromosomes. Sex-influenced traits behave differently in males and females, and they occur on autosomal chromosomes.
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An example of a sex-influenced trait from class is?
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Male-pattern baldness
Dominant in males Recessive in females |
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What is an inherited condition that is not traceable to the genome?
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cytoplasmic inheritance
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Why is mitochonrial DNA so much more likely to develop mutations?
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Has no repair mechanisms
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T or F?
All mtDNA comes from maternal cytoplasm? |
True
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What system is most affected by faulty cytoplasmic inheritances?
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CNS
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A pedigree showing the inheritance of cytoplasmic inheritance caused by mitochondrial mutations shows that who can only transmit mutations to offspring?
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females
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Characteristics of Leber Hereditary Optic Neuropathy.
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degeneration of optic nerve
center field of vision goes 1st 20-30 year olds mtDNA disorder variable expressivity |
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X-linked condition
Long,large face Protruding ears Varying mental retardation |
Fragile X
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What is the penetrance of Fragile X in men and females?
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80 percent in males
40 percent in females |
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Explain anticipation.
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Condition that shows frequency and severity in subsequent generations.
More frequency=more severity |
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What does fMRP stand for and what is its function?
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fragile x mental retardation protein
codes for TNR |
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What is the basis of the cause of Fragile x syndrome?
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TNRs
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What are the amount of repeats that a NL, pre-mutated, and mutated individuals?
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NL 5-50
Pre-mutated 50-200 Mutated 200-4000 |
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What is the reason for the TNR stutter?
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Composition of C-G complexes
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What deals with the entire chromosome number?
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Cytogenics
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What is characterized by the correct chromosome number?
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Euploid
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What is characterized by an entire extra chromosome set?
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Polyploid
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What is characterized by having one extra or one missing chromosome?
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Aneuploid
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What are two types of aneuploid?
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Monosomy-missing
Trisomy-extra |
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What lab is usually run to diagnose any trisomies?
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Lab 21,13,18
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What is the most common reason for aneuploidy?
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non-disjunction
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Non disjunction occurs during what phase?
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anaphase
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Characteristics of Trisomy 21
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mental retardation
upward slanting of upper and lower eyelids(palpebral fissure) hypotonia short neck prone to GI obstruction Increase risk of Leukemia |
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What is the occurance of Trisomy 21?
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1/1000 live births
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What are the 6 anticipatory guidances in children with Trisomy 21?
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Heart defects by age 1
Strabismus by age 4 Hypothyroidism annually Sensorineural and hearing loss by 6-8 mths Instability of T1-2 Developmental interventions |
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What syndrome is the 2nd most common trisomy, characterized by a small face, mouth, misshapen ears, small for gestational age, clenched fists with overlapping fingers?
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Trisomy 18- Edwards
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What is the occurance of Trisomy 18?
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1/6000
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Characteristics of Trisomy 13?
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Cleft lip, septal defects, lethal in first year, mental impairment
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What is the occurance of Trisomy 13?
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1/10000
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Characterized by XXY, long limbs, gynecosmastia, abnormally small testes, learning deficiencies, and prone to breast cancer?
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Klinefelter Syndrome
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What is the occurance of Klinefelter syndrome?
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1/1000
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X-O, short, webbing at neck, heart disease, no secondary sex characteristics
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Turner's Syndrome
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what is the occurance of Turner's syndrome?>
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1/2000
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T or F?
Can Turner syndrome be treated with estrogen at a very young age? |
True
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In banding patterns of chromosomes, the "p" arm is___ and the "q" arm is?
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p = short
q = long |
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What is the meaning of
C8q21? |
Chromosome 8, long arm q, region 2, region 1 of region 2
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What is the gene that determines the path of the embryo?
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TDF, testes determining factor
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What is the result of a hitch-hiking TDF?
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XX males
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What is the result of an absent TDF?
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XY females
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What is it called when some genes on chromosomes are not accessible?
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imprinting
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What chromosome did we discuss in class that is involved in imprinting diseases?
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15
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What disorder results from the the deletion of the gene on the paternal chromsosome and is not replaced by a gene on the maternal chromsosome?
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Prader-Willi syndrome
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What disorder is characteristic of a deletion on the maternal chromosome with no replacement by the paternal chromosome?
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Angelmans
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What are the clinical features of prader-willi?
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overweight, extreme hunger, complications with obesity, may frequently choke, mild-severe mental retardation
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What are clinical features of Angelmans?
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Ataxic gait, standing on one foot, odd posture, always smiling, mild-moderate mental retardation
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What are disorders stemming from missing or malfunctioning enzymes involved with?
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Metabolism disorders
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T or F
Most metabolic disorders are found in the sex chromosomes? |
False, most are autosomal
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T or F?
Carriers of metabolic disorders are asymptomatic? |
True
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What disorder is characterized by not being able to convert phenyl-alanine, causing a build up?
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PKU
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May form severe types of mental retardation, all infants are tested at birth, affected individuals are on a restricted medical diet?
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PKU
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T or F?
A female with PKU doesnt have to go on a restricted medical diet while pregnant? |
PKU
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Describe Galactosemia?
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Hepatic insufficiency
Cataracts Failure to thrive Developmental delay Medical diet restriction of galactose |
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Describe MCAD deficiency?
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Multiple organ failure
Cerebral edema Liver/kidney damage Vomit and lethargy after fasting Add glucose to IV Lead to death by 2 |
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A carbohyrdate disorder
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galactosemia
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A fatty acid disorder
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MCAD deficiency
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A lysosomal storage disorder
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Hurler
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Describe Hurler syndrome?
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Multi-organ dysfunction
enlarge liver bone disorders Gargoyle appearance degree of mental retardation |
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What is the fertilized egg called?
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zygote
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What is the division stage called?
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cleavage
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Upon the first cleavage of the embryo what results?
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2 celled embryo (day 2)
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T or F?
The 2 cell embryo is totipotent? |
True
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What does totipotent mean?
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Ability to develop into the entire embryo plus fetal contribution, utilization of entire genome
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When does a cell lose its ability to be totipotent?
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After compaction
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At what stage does compaction take place?
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Morula, 16 cell stage, at day 4-5
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How many cells become entraped during compaction?
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2
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At day 6-7, a solid ball hollows out, and cells become limited or ______ .
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Pluripotent
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What does the 2 entraped cells become?
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ICM
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From the 14 cells that surround the 2 cells, it becomes the___?
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Trophoblast
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What are the two populations that the trophoblast becomes?
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syncytium
and cytotrophoblast |
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What is the role of the syncytium?
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secretes enzymes to degrade endometrium
responsible for attachment and implantation |
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What is the role of the cytotrophoblast?
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Remains after implantation as the trophoblast reminant and becomes fetal part of placenta
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T or F?
While the trophoblast does it's job, the ICM flattens out? |
True
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What is the term given to the flattened ICM?
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epiblast
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What are the three layers of the epiblast and what do they make up?
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Ectoderm-CNS, skin, and hair
Endoderm-Gut, digestive tract Mesoderm-muscles, cardio, vessels, bone, cartilage |
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What is the origin of the chorion?
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cytotrophoblast
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What are the fingerlike projections from the chorion called?
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chorionic villi
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Fetal capillaries under the chorionic villi connect to the fetal capillaries in the mesoderm to form the_____?
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umbilical cord
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Extra cells from the blastocyst (2 cells engulfed previously) form a dome called the?
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Amnion
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T or F?
The embyro eats the amnion? |
False, the embryo backs into the amnion after the amnion forms from the blastocyst
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As the embryo forms, a plate develops in the center. The mesoderm subset forms a rod of tissue called ____?
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notochord
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What is the function of the notochord?
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Sends signals to layers and lays down rules for differentiation
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If you remove this it will cause the stoppage of the growth of the limbs?
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AER, apical epidermal ridge
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This controls set up of polarity.
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ZPA, zone of polarizing activity
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What is a teratogen?
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Birth defect causing agent
Ex: retinoic acid, disrupts cellular activity |
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What is a blastema?
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A mass of stem cells that forms under a stump, de-differentiated cells that are capable of regrowing
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What organism has been studied and compared to human development?
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fruit fly, drosophilia
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Bad signals cause mutations and can cause______?
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SIM, segment identity mistakes
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The gene is found in most organisms. Specifically found on a chromosome segment of drosophila; segments line up to mimic head and tail.
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HOX genes
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These control expression of genes responsible for making anatomical structures
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Hox genes
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T or F
Hox genes do not code for transcriptional factors |
False, they do code for TFs
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Transcription factors code for?
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DNA binding proteins
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What is secreted from cells to stimulate secreted ligands?
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diffusible factors
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This is a 2nd way of communication, signals AER, notochord, ZPA. Bind to receptors and stimulate cell to release own ligands.
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Secreted ligands
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T or F
Cells that secrete Hox genes will ship them out for other cells to use? |
False, cells that secrete hox genes will use them locally
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What is the basic fundamental signal that embryos use for correct development?
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SHH, sonic hedge hog gene
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What is a disorder caused by a SIM and is charactistic of a fused nose, and cyclops appearance?
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holoprosencephaly
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What did cloning proove?
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That differentiation was not permanent.
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T or F?
Cloning involves the fustion of an enucleated oocyte and donar cell fibroblast? |
True
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