Question 1

Direction of shell coiling in Lymnaea peregra is strongly and most directly influenced by ____.

Accepted Answer

A) the phenotype of the father 
B) the genotype of the mother 
C) the genotype of the embryo itself 
D) the genotype of the father 
E) the phenotype of the mother

Question 2

The genes for light eyes lt; light and straw bristles stw; straware tightly linked on chromosome 2 in Drosophila melanogaster.The Malpighian tubes of lt larvae and adults are maternally affected in that Malpighian tubes of lt/lt organisms,whose mothers were lt⁺/lt and have more yellow pigment than those from lt/lt mothers.There is no maternal effect associated with the straw locus.Give the phenotypes of the offspring from the following crosses.

Accepted Answer

The answer of The genes for light eyes lt; light...

Question 3

In aerobically cultured yeast,you isolate a petite mutant.You believe it is a suppressive mutant.Which cross would you do below to determine that it is indeed suppressive?

Accepted Answer

A) petite × petite yields half petite and half wild type 
B) petite × petite yields all petite 
C) wild type × wild type yields petite 
D) petite × wild type yields all petites 
E) petite × wild type yields half petite and half wild type

Question 4

You discover a new alien race that you decide to call the PAMMARIANS.They are different from us in that they have three sexes,called Q,R,and S.All three sexes must fuse their gametes to form a new PAMMARIAN and you thought dating on the Earth was hard! .They have nuclear DNA and extrachromosomal organelles,similar to mitochondria,called MITOCHLORIANS,which have their own DNA.The R gender is like human females they donate the cytoplasm during the mating .Q and S do NOT donate cytoplasm during mating,like human males.Which of the following is TRUE?

Accepted Answer

A) In a mating,if only the S gender individual has a mitochlorian DNA mutation that causes a phenotype,the offspring WILL HAVE a mitochlorian mutant phenotype. 
B) In a mating,if only the Q gender individual has a mitochlorian DNA mutation that causes a phenotype,the offspring WILL HAVE a mitochlorian mutant phenotype. 
C) In a mating,if the S and Q genders have a mitochlorian DNA mutation,the offspring will be mutant as well. 
D) In a mating,if only the Q gender individual has a mitochlorian DNA mutation that causes a phenotype,the offspring will have NO mitochlorian mutant phenotype. 
E) In a mating,if only the R gender individual has a mitochlorian DNA mutation that causes a phenotype,the offspring will have NO mitochlorian mutant phenotype.

Question 5

To which of the following does the term heteroplasmy refer?

Accepted Answer

A) conditions in which the germ plasm is a mixture of dominant and recessive genes 
B) cells with a variable mixture of normal and abnormal organellar genomes 
C) heterozygous individuals with more than one gene pair involved 
D) a circumstance that is homologous to incomplete dominance 
E) various stages of development of mitochondria and chloroplasts

Question 6

Kearns- Sayre syndrome KSS results in progressive loss of vision and hearing,as well as heart defects.What is the genetic basis for this disease?

Accepted Answer

A) ATP builds up and runs the electron transport chain backwards. 
B) Reactive oxygen species mutate DNA. 
C) Ageing shortens the telomeres of the mitochondrial DNA. 
D) Too much sunlight damages mtDNA. 
E) Deletions occur in mtDNA,and the proportion of defective mtDNAs increases as the severity of the symptoms increases.

Question 7

In organelle heredity,which of the following is TRUE?

Accepted Answer

A) In a reciprocal cross,the offspring will always have the phenotype that the mother egg has. 
B) In a reciprocal cross,the offspring will have the phenotype of the mother's genotype. 
C) In a reciprocal cross,the offspring will have different phenotypes depending on which phenotype the father has. 
D) In a reciprocal cross,the offspring will have varied phenotypes depending on which X chromosome is converted into a Barr body. 
E) In a reciprocal cross,the imprinted gene will always come from the mother.

Question 8

Molecular/structural orientations gradients)in an egg are thought to play a significant role in development.What evidence indicates that the maternal genotype is involved in providing such gradients?

Accepted Answer

A) Results indicate that the snail shell coiling is passed exclusively from the mother. 
B) The snail shell coiling depends on the genotype of the mother and the offspring. 
C) The snail's father's genotype dictates the next generation's phenotype. 
D) Snail shell's coil based on environmental conditions. 
E) Results non- Mendelian)indicate that the direction of shell coiling in snails is determined by the genotype of the mother,not the genotype of the zygote.

Question 9

Why is variegation in four o'clock plants determined by the phenotype of the ovule source?

Accepted Answer

A) Dominant genes demonstrating variegation come from the ovule. 
B) The mitochondria determine the leaf coloration,and the mitochondria are inherited through the ovule. 
C) Recessive genes demonstrating variegation come from the ovule. 
D) The chloroplasts determine the leaf coloration,and the chloroplasts are inherited through the ovule. 
E) The ovule nuclear genome contains the genes for leaf coloration.

Question 10

In what way do segregational petite mutations differ from neutral petites?

Accepted Answer

A) Segregational petites follow Mendelian inheritance as a result of the influence of nuclear genes; neutral petites,when crossed to wild type,produce only wild- type,normal- sized colonies. 
B) When a neutral petite is crossed to a segregational petite,all offspring are neutral petites. 
C) Neutral petites follow Mendelian inheritance as a result of the influence of nuclear genes; segregational petites,when crossed to wild type,produce only wild- type,normal- sized colonies. 
D) When a segregational petite is crossed to a wild- type cell,all offspring are petite.However,when a neutral petite is crossed to a wild- type cell,all offspring are wild type. 
E) Neutral petites are dominant and segregational petites are recessive mitochondrial genes.

Question 11

Which of the following matings indicates that a Chlamydomonas mutant with photosynthetic defects that resulted from a deficiency in chloroplast translation is located on the chloroplast genome?

Accepted Answer

A) mt+ photo- × mt- photo+ yields all str- 
B) a petite × alpha wild type yields all petite 
C) mt+ photo+ × mt- photo- yields all str- 
D) mt+ photo- × mt- photo+ yields mt+ photo+ and mt- photo- 
E) mt+ photo- × mt- photo+ yields mt+ photo- and mt- photo+

Question 12

Molecular/structural orientations gradients in an egg are thought to play a significant role in development.What is the origin of such gradients?

Accepted Answer

A) During formation of the egg,nutritional as well as informational molecules RNAs)are placed in appropriate positions for the development of the embryo. 
B) When an egg is fertilized,the gradient is set up based on the side of the egg on which the most mitochondria reside. 
C) During early development,the nucleus is placed into position of the highest concentration. 
D) Where the sperm penetrated the egg is the area of highest concentration. 
E) The side facing up has the lowest concentration of molecules.

Question 13

Which of the following organelles are involved in the general category of organelle heredity?

Accepted Answer

A) lysosomes and peroxisomes 
B) factors and episomes 
C) mitochondria and chloroplasts 
D) Golgi apparatus and rough endoplasmic reticulum 
E) Golgi apparatus and nuclei

Question 14

Name two human disorders that appear to be transmitted extrachromosomally.

Accepted Answer

A) Duchenne muscular dystrophy and Down syndrome 
B) cri- du- chat syndrome and Leber's hereditary optic neuropathy 
C) poky chromosome syndrome and kidney cancer 
D) myoclonic epilepsy and ragged red fiber disease and Leber's hereditary optic neuropathy 
E) reactive oxygen syndrome and myoclonic epilepsy and ragged red fiber disease

Question 15

Approximately one in 5000 humans either have a mitochondrial DNA disorder or are at risk for developing such a disorder.What future approach involving nuclear transplantation might be available to treat mtDNA- based human disorders?

Accepted Answer

A) mitochondrial suppression 
B) mitochondrial activation 
C) mitochondrial replacement therapy 
D) nuclear disintegration 
E) nuclear activation

Question 16

____phenotypes are passed equally to offspring by both males and females.

Accepted Answer

A) Autosomal recessive 
B) X- linked dominant 
C) X- linked recessive 
D) Mitochondrial 
E) Autosomal dominant

Exam 9: Extranuclear Inheritance