There is a null allele that is common among french canadians. The allele is defined by a frameshift mutation in the portein-encding region of the FAH gene. Individuals homozygous for this allele would show:

a) reduced levels of transcrption of the FAH gene which would result in the production of reduced amounts of functional enzyme.

b)nomral levels of transcription of the FAH gene which would result in the production of a poorly functioning enzyme

c) normal levels of transcription of the FAH gene but the enzyme prouced would be nonfunctional

d)no transcription of the FAH gene and therefore no enzyme would produced would be nonfuncationl

e) more than one of teh aboce is possible

c) normal levels of transcription of the FAH gene but the enzyme prouced would be nonfunctional

Liver and kidney cells contain hight levels of fumarylacetoacetate hydrolase and this is correlated with a high rate of FAH transcription. Other types of human cells contain little or no fumarylacetoacetate hydrolase. What best explains this situation?

a)Liver an kidney cells have high rates of transcription of the FAH gene because these cells have the FAH gene. Many other cell types lack the FAH gene.

b) Liver and kidney cells have the regulatory region for the FAH gene and other types of cells lack the regulatory region for the FAH gene.

c) Fumarylacetoaceate hydrolase could be absent in certain cell types because these cells lack certain transcription factors required to activate transcription of the FAH gene.

d) Fumarylacetoaceate hydrolase could be absent in certain cell types becaseu the FAH gene is unmethylated in these cells.

e) none of the above

c) Fumarylacetoaceate hydrolase could be absent in certain cell types because these cells lack certain transcription factors required to activate transcription of the FAH gene.

A number of otehr genetic condionts have symptoms very similar to HT1. For example, Hereditary Tyrosinemia Type 2 and Hereditary Tyrosinemia Type 3 produce phenotypes that are very similar to HT1. HT2 is controlled by a gene which maps to chromosome 16 and HT3 is controlled by a gene which maps to chromosome 12.

What explains this phenomena?

Symptoms similar to those seen in HT1 can be seen in patients who have liver problems due to alcholism.

what explains this phenomena?

In the french canadian population several different mutant alleles of the FAH gene are present. Individuals homozygous for this null allele defined by frameshift mutation in the protien encoding region of the FAH gene, show severe, early onset of symptoms. Individuals homozygous for certain nonsense mutations of the FAH gene can also show severe symptoms but the onset may occur later in life. A less evere phenotype is sometiems seen in individuals who are homozygous for missense mutations of teh FAH gene.

What explains this phenomena?

Charles Drawin used Gregor Mendel's laws of ingeritance to explain the diversity of phenotypes seen in various breeds and species.

true or false?

In tay Sachs Disease an enzyme involved in the biosynthesis of gangliosides is non-functional.

True or False

Wildtype rat snakes are black. Snake breeders have rat snakes that are pale tan and pale yellow. Pale tan colour is controlled by recessive allele, t, and pale yellow colour is controlled by recessive allele y. Bredders wondered if alleles t and y were allels of same gene or alleles of two different genes. Snakes homozygous for t allele were crossed to snakes homozygous for y allele. Which of the following results would convince you that t and y are ealleles of two different genes?

a) F1 all balck, F2: 113 black, 38 tan, 34 yellow, 13 albino

b) F1 all are intermediate (yellow tan) F2: 58 tan, 48 yellow, 100 intermediate

c) F1: all intermediate (yeelow tan) F2: 300 black, 100 intermediate

d) F1: all tan F2: 150 tan, 50 yellow

e) more than one of the above

If tortoiseshell cat is crossed to black cat, resulting female offspring can have black coats, yellow coast and tortoiseshell coats.

True or False

In referance to meiosis and mitosis in humans:

i) non-identical sister chromatids separate during anaphase II of meiosis

ii) After S phase there are 92 chromosomes

iii) first polar body contains the same number of chromatids as the secondary oocyte

iv) The X and Y chromomes pair during prophase I of meiosis in males.

v) females are born with their primary oocytes arrested in prophase I of meiosis

Which statment is incorrect?

Cock-feathering in chichkens is a sex-limited trait determined by the autosomal recessive genotype, c. The dominat allele, C, produces hen-feathering. Only homozygous recessive males are cock-feathered. Another gene which maps to the Z chromosome, controls barred plumage. Birds with the dominant allele, B, have barred feathers. Birds homozygous or hemizygous for the recessive allele are non-barred. Two birds were crossed many times and the following offspring were produced:

females

barred + cock-feathered: 0

nonbarred + cock-feathered: 0

barred +hen-feathered: 51

Non-barred + hen-feathered: 53

males

barred +cock-feathered: 47

non-barred + cock feathered: 0

barred +henfeathered: 50

non-barred+henfeathed: 0

which best describes parents of these offspring?

a) male parent heterozygous for both genes

b)female parent has non-barred feathers and hen-feathering

c)male parent has non-barred feathers and hen-feathering

d) female parent could be heterozygous for both genes

e) female parent is cc and Bb.

a) male parent heterozygous for both genes

Males Z^BZ^b --c (half of his daughters are barred)

Females Z^BW - C (she has no barred sons)

The number of genes in the human genome is the same as the number of proteins found in human cells.

True or False?

megaspores of flowering plant have 34 chromoemes. How many chromosomes would be found in egg cell of endosperm of this plant?

34 in egg cell, 102 in endopserm

megaspore (4 produced 1 survies) --> mitosis --> female gametophyte: embryo sac --> double fertilzation --> one sperm fertilizes the egg cell and the other sperm combines with 2 polar nuceli --> 2N zygote and 3N endosperm prodcued

a flowering plant that is 2N=64

i) cells of the gametophtye would have 64 chromosomes and the cells of the sporophyte would have 128 chromomes

ii) the cells of the embryo sac are haploid

iii) one microsporoctye undergoes mitosis and

iv) in prophase I of meioisi there would be 64 chromsomes (consisting of 2 chromatids each) and in propahse II of meiosis there would be 32 chromomes (constisting of 1 chromated each).

v) teh pollen grain is the male sporophte

which is correct?

Statement II

megasporcyte --> meiosis-->megaspore (4 produced 1 survived) -->mitosis--> female gametophyte: embryo sac

Baby girl has normal alleles for hexosamindase A gene and yet she is severaly affected with Tay Sachs Disease.

What phenomenon could best exlpan this situation?

Gregor mendel would have been aware of wich of the following sceintific discoveries?

a) watson and crick's double helix model for DNA structure

b) The Cell Theory as prosoposed by Scheidan, Schwann and Virchow

c)Dawrin's theories on speciation and natural selection

d) chromosome strucutre as propsed by sutton

e) more than one of the above

Immediately after S phase of cell cycle, a nomral human cell has 92 chromosomes. 

vrai ou faux?

Rats of the dumbo breed have large falt ears. there are two varieties of dumbo rats -- one with tulip ears and one with saucer ears. saucer ear phenotype is due to a recessive allele sa. the tulip ear phenotype is due to another reciessive mutation called tu. Alleles sa and tu could be alleles of the same gene or the could be alleles of two different genes. To answer this quetion, rats homozygous for the sa allele were crossed to rats homozgous for the tu alele. which of the following rulstles  would best convince you that sa and tu are two different allels of the same gene?

 if F1 was:

a) all normal/ wildtype ears

b) all have tulip ears

c)all have saucer ears

d) all have ears which are intermediate between tulip and saucer

e) more than one of the above

e) more than one of the above

(b,c,d)

The following statments reger to meiois and mitsos in a flowering plant that is 2N=42

a) in prophase 1 of meiosis, there would be 42 chromosomes (consisting of 2 chromatids each) and in prophase II there would be 21 chromomes consting of 1 chromatid each)

b) THe cells of the embryo sac have 42 chromosomes 

c) The male gametophyte is the pollen grain

d) Megaspores undergo meiosis to form the female gametophyte and microscopores undergo meiosis to form the male gametophypte. 

e) endopserm cells produced by this plant would have 21 chromosomes 

which statement is true?

c) male gametophyte is the pollen grain

in human meiosis and mitosis,

a) non-identical sister chromatids separate during anaphase II of meiosis

b) DNA replication occurs once before meiosis I and once meiosis II

c) The first polar body contains the same number of chromatids as the secondary oocyte

d) a zygote has 23 chromosomes and 46 chromatids

e) Males are born with their primary spermatocytes arrested in prophase I of meiosis 

which of these statments are correct (more than one)

a) non-identical sister chromatids separate during anaphase II of meiosis

d) A zygote has 23 chromosomes and 46 chromatids 

The start codon AUG initiates transcription in the nucleus of eukaryotic cells.

True or False

False

AUG inititates translation in the cytoplasm of eukaryotic cells 

Ehlers Danlos Syndrodrom Type III is a rare single gene disorder. The gene is fully penetrant. THe gene responsible for this disorder, COL#A1 maps to chromosome 2 and encodes collagen III. Collagen III is found in skinm tendons and bone, Individuals with EDS III show joint laxity, skin hyper-extensibility and bruise easily.

Which statment best explains the high rate of COL3A1 gene transcription in skin, tendon and bone cells?

a) skin tendon and bone cells have high rates of transcripition because only these cells have the CO3A1 gene. 

b) COL3A1 gene expression is high in skin, tendon and bonecells because certain transcripiton factors are bound to the regulatory region of the COL3A1 gene.

c) All cells would transcribe the COL3A1 gene but only skin, tendon andb one cells would translate the COL3A1 mRNA.

d) The skin, tendon and bone cells have the promoter region for the COL3A1 gene and all other cells lack the promoter region for the COL3A1 gene. 

e) moretha one of the above is true

When COL3A1 gene is transcribed, the resulting mRNA is a complemtary copy of both the regulatory region and the protien encoding region.

True or Flase

a rare hpomorphic allele of the COL3A1 gene. Allele is defined by a missense mutation in the protien encdoing region of the COL3A1 gene. Transcription of this allele would:

a) result in the production of reduced amounts of collagen III

b) result int hte production of increased amounts of collagen III

c) result in the proudction of nonfuncational collage II

d)result in the absnece of collagen III

e) result in the prodcution of a poolry fucntioning collagen III

e) result in the production of a poorly functioning collagen III

hypomorphic - reduced

protein-encoding region- protein doesnt fuction prop. 

Many other forms of EDS. EDS Type II is controled by the COL5A gene which maps to chromosome 9. EDS-Type VI is contrlled by a gene that encodes lysyl hydroxylase which maps to chromome 1. Patients affected with EDS-VI or EDS-II share many of the symptomes seen in pateints with EDS-III.

What explains this phenomena?

Individuals woh inherit a mutant COL3A1 allele from their mothers are more liekly to be severly affected with EDS III than inidivduals who inherit a mutant COL3A1 allele from their fathers.

What explains hits phenomena?

NUmber of different mutant alleles of the COL3A1 gene. A particular null allele is associated with people of Irish descent and affected individuals bruise easily. Individuals with the mutant allele assosiated with EHlers-Danolas Syndrome Type III,  bruise easly, have joint laxity and show skin hyper-extensibility. Some indiviudals who have certain mutatn COL3A1 alleles only show skin hyper extensiliblty. 

WHat explains this phenomina? 

The probibility that you have inherited 23 of your maternal grandomthers chromosomes is 50%

true of false.

false. 

fucker.

which of the following proteins is nonfunctional in Tay Sachs Disease?

a) tyrosinase

b) hexosaminidase A

c) lysosomal alpha-glucosidase

d)phenylaline hydoxylase

e) alpha antitrypsin

Barred feathering in birds is controlled by a dominant sex linked allele B. Bireds with non barred featering are homozygus or hemizygous for the recsissive allele, b. Two birds were crossed many times and the following offspring were produced. 

females: barred 53, nonbarred 52

males: barred 105, nonbarred 0

which statment correctly desrbies parents of offspring?

a) both male nad female parents have barred feathers

b) male parent is homzygous for recssive allele b, an female parent is hemizgous for dominant allele B

c) both male parent and female parent are heterozygous for barred feathering gene

d) female parent is heteryoygous Bb and male parent is hemizygous for the dominant allele B.

e) none of the above

In a male affected with sex linked ADL, all X chromosomes would be euchromatic.

True or False

True,

in males X must be activated

euchromatic - activated

Rare hypomorphic allele of the GSDII gene.  The allele is defined by a missense muation in the protien encoding region of the GSDII gene. In indivuduals homozygus for this allele there would be:

a) reduced levels of transcription of the GSDII gene which would result in the production of reduced amounts ofthe alpha-glycosidase

b) normal levels of thranscription of the GSDII gene which would reslut in the production of a poorly functioning alpha-glycosidase

c) normal levels of transcription of the GSDII gene but the alpha glycosidase produced would be nonfunctional

d) no transcription of the GSDII gene and therefore no alphaglycosidase produced would be nonfunctional

e) more than one of the above is possible

An individual with DSDII was found to have two nomrall allels or the GSDII gene. Researchers later noted that both normal GSDII alleles were highly methylated. 

What explains the following phenomena?

Some of the cardiac symptoms seen in GSDII can be seen in patients who have bacterial and viral infections.

What explains this phenomina?

there are a number of different mutant alleles of the GSDII gene. Null alleles are usually associated with adult onset of the diease.

What explains this phenomina?

Cardiac and skeletal muscle cells show very high transcription rates of the alpha glycosidase gene. Which of the following statments best explains the high rate of alpha-glycosidase gene transcription in cardiac and skeletal muscle cells?

a) cardiac and skeltal muscle cells have high rates of transcription because only theses cells have the alpha-glycosidase gene

b) muscle cells have apromoter region for the alpha glycosidase gene and all otehr cells would lack the promoter region for tha lpha glycosidase gene.

c) all cells would transcribe the alpha glycosidase gene but only muscle cells would translate the alpha glycoidase mRNA

d) Alpha glycosidase gene expression is high in muscle cells because certain transcription factors are bound to the regulatory region of the alpha glycoisdase gene in these cells.

e) more than one of the above

In patients affected with GSDII, the excess cellular glycogen is stored in the lysomsomes. A simlar storage situation is seen in which of the following diseases?

a) PKU

b) Tay Sachs Disease

c) Sickle Cell Anemia

d) Albinism

e) more than one of the above

e) more than one of the above

PKU and Tay sachs disease 

Fifty percent of sperm cells produced by a rooster (male chicken. a durrh) contain a Z chromosome and fifty percent contain a W chromosome.

True or False?

False

all would be ZZ in rooster. 

In genomic imprinting, certain alleles can expand from generation to generation.

True or False

False

The Stop codon, UAA, UAG, and UGA, terminate transcription in the nucleus of eukarytoic cells. 

True or False?

False,

AVG, UAG, and UGA are stop codons. 

A number of different alleles (in the homozgygous condtion) can cause TAY Sachs disease

true or false?

TRUE

mild vrs bad

Which statement is true in reference to a flowing plant that is 2N=24?

a)Megaspores undergo meiosis to form the embryo sac

b) Tube cell of the male gametophyte has 42 chromosomes

c) The female gametophyte is located in the stamens of flowers

d) In prophase I of meiois there would be 42 chromomes (consisting of 2 chromoatids each) and in prophase II of meiosis there would be 21 chromosomes (consisting of 1 chromatids each) 

e) Endosperm cells produced by this plant would have 63 chromosomes.

e) Endosperm cells produced by this plant would have 63 chromosomes

endosperm  is 3N.

so 42/2*3= 63.