genetics terminology + terminology

Question 1

age of onset is earlier and earlier presentation in successive generations or severity of disease worsens with successive generations

Answer 1

anticipation

Question 2

diseases with anticipation

Answer 2

Huntington disease: trinucleotide repeats expand with successive generation

Question 3

how often a genotype causes a particular phenotype
not all with mutant genotype show mutant phenotype
mutation appears to skip generations but still present

Answer 3

incomplete penetrance (may not get cancer)

Question 4

2 alleles

neither is dominant

Answer 4

codominance (ABO blood type)

Question 5

severity of phenotype varies from one individual to another

Answer 5

variable expression (tuberous sclerosis - different disease severity)

Question 6

single gene has more than one effect on phenotype

Answer 6

pleiotropy (PKU: ID, light skin, musty body odor)

Question 7

mutations at different loci can produce the same phenotype

Answer 7

locus heterogeneity:
marfanoid body habitus in:
marfan syndrome
MEN-2B
homocysteinuria

Question 8

cells in body have different genetic makeup (lose genetic information during mitosis)

Answer 8

mosaicism

Question 9

phenotype differences depend on whether mutation comes from mother’s or father’s genetic material (some genes normally inactivate one of the sex’s chromosome)

Answer 9

imprinting:
both caused by deletion of gene on chrom 15
Prader-willi syndrome
angelman syndrome

Question 10

deletion of gene on chrom 15

deletion of assigned active allele: paternal

Answer 10

Prader-Willi syndrome = Paternal

Question 11

deletion of gene on chrom 15

deletion of assigned active allele: maternal

Answer 11

angelMan syndrome = Maternal

Question 12

presents in infancy: hypotonia, poor feeding, almond-shaped eyes, downward turned mouth
symptoms: hyperphagia, obesity, short stature (partial GH deficiency), ID, behavior: tantrum, skin-picking, OCD, hypogonadotropic hyopgonadism → genital hypoplasia,childhood OP, delayed menarche

Answer 12

Prader-Willi syndrome = Paternal

Question 13

diagnosis of prader-willi syndrome

Answer 13

FISH

Question 14

ID
seizure
ataxia
inappropriate laughter

Answer 14

Angelman syndrome

Question 15

amplify a sequence of DNA in 3 steps:

1) DNA denaturation: heat DNA → 2 strands separate
2) annealing: cool DNA + add DNA primers (in vivo is RNA primer) that bind to sequence to be amplified
3) elongation: DNA poly replicates sequence after the primer

Answer 15

PCR

Question 16

sort + separate PCR DNA fragments based on size

Answer 16

gel electrophoresis

Question 17

put PCR products in wells
run current through gel: DNA travels toward + electrode (anode)
smaller molecules travel further

Answer 17

gel electrophoresis

Question 18

gel to separate protein particles

Answer 18

protein electrophoresis

Question 19

1) separated DNA by size with gel electrophoresis
2) take DNA sample and put on filter and denature DNA to separate strands → labeled DNA probe (radioactive or fluorescent) binds/identifies DNA sample

Answer 19

southern blot
Down south = DNA
DNA sample
DNA probe

Question 20

use DNA probe to identify RNA sample

Answer 20

northern blot
Rude yankees = RNA
RNA sample
DNA probe

Question 21

use antibody probe to identify protein sample

Answer 21

western blot
Beef: protein
protein sample
antibody probe

Question 22

use oligonucleotide probe to identify DNA binding proteins sample (TF)

Answer 22

southwestern blot

Question 23

analyze patient’s blood to determine if ANTIGEN is present in blood using antibodies (in wells of a plate)
anti-antigen antibodies added (an enzyme substrate) and bind to antigen →emit a color which detects the antigens presence

Answer 23

direct ELISA test

Question 24

analyze patient’s blood to determine if ANTIBODIES are present in blood using antigen (in wells of plate)
anti-antibody antibodies added (an enzyme substrate) and bind to antibodies → emit a color which detects the antigens presence

Answer 24

indirect ELISA test

HIV antibodies in blood: ELISA screening test
if +: confirmatory test is western bloot

Question 25

use DNA or RNA fluorescent probe to bind to gene of interest

no fluorescence = deleted gene

Answer 25

FISH

Question 26

cloning recombinant DNA molecules
use mRNA that corresponds to gene to be cloned
use reverse transcriptase to turn mRNA → complementary DNA (cDNA) (only contains EXONS since from mRNA = coding region)
insert cDNA into bacterial plasmid: replicate cDNA as bacteria replicates

Answer 26

cloning

Question 27

delete gene from mouse’s genome: knock-out mouse
insert gene: knock in mouse
insert gene randomly: constitutive insertion
targeted insertion: conditional insertion

Answer 27

modifying gene expression

Question 28

metaphase chromosomes (condensed)
diagnose chromsomal imbalances by gross architecture

Answer 28

karyotyping

trisomy or sex-chromosome disorders

Question 29

amniotic fluid test to diagnose trisomy 21 in utero

Answer 29

karyotyping