Test your basic knowledge |

GRE Molecular Biology

Instructions:

Answer 40 questions in 15 minutes.
If you are not ready to take this test, you can study here.
Match each statement with the correct term.
Don't refresh. All questions and answers are randomly picked and ordered every time you load a test.

This is a study tool. The 3 wrong answers for each question are randomly chosen from answers to other questions. So, you might find at times the answers obvious, but you will see it re-enforces your understanding as you take the test each time.

1. What does the Law of Segregation state?
Small loops of dsDNA that exist within bacterial cells - but not as a part of the single - large chromosome.They replicate independently of the larger chromosome and can be freely exchanged from bacterial cell to bacterial cell via extensions of cyto
1. Males and females are equally likely to have the trait 2. Traits often skip generations 3. only homozygous individuals have the trait 4. Traits can appear in siblings without appearing in parents 5. If a parent has the trait - those offspring who
That two alleles for a given trait separate from each other during meiosis - and thus - end up in different sperm or egg cells. So an organism can pass on a W or a w from a set of Ww - but never both
Proteins that attaches to the operator sequence only when a certain compound is present in the environment

2. Describe the lac operon model
RNA polymerase attaches to promoter sequence immediately prior to the gene that is to be transcribed - follows along the DNA strand - reading DNA into mRNA ? repressor protein (controlled by a regulatory gene) binds to operator not allowing RNA to mo
This is a genetic inheritance pattern that results from the fact that certain alleles seem to be encoded differently depending upon which parent the allele comes from.
In the nucleoid region
Rediscovered mendels work to help figure out why traits were passed on in the patterns that he saw. Helped to discover the concept of gene linkage

3. What is Mitochondrial (maternal) Inheritance?

4. What are characteristics of X-linked recessive traits?
When the different alleles for a trait each code for enough protein so that - when they occur together - two different - normal proteins are made and show up in the organisms phenotype. For examples - blood types Ia - Ib - and Ia and Ib will be codom
1. Trait is far more common in males than in females 2. All daughters of a male who has the trait are heterozygous carriers 3. There is no male-to-male transmission 4. Mothers of males who have the trait are either heterozygous carriers or homozygous
Males only have one X chromosomes in addition to their Y chromosome. If this X has the mutant gene on it - there is no normal gene to override. Female have a chance of having a normal gene on the other X that can produce enough normal protein that th
Defective proteins

5. Who is Thomas Hunt Morgan
Plasmids that contain antibiotic resistance genes - which code for enzymes that may break down or interfere with antibiotics.
Rediscovered mendels work to help figure out why traits were passed on in the patterns that he saw. Helped to discover the concept of gene linkage
Proteins that attaches to the operator sequence only when a certain compound is present in the environment
The physical features of an organism

6. Define Inducible enzymes
Enzymes that can be induced/turned on when in the presence of a particular substance
Rediscovered mendels work to help figure out why traits were passed on in the patterns that he saw. Helped to discover the concept of gene linkage
Defective proteins
The degree to which one expresses a trait depends upon the ratio of dominant to recessive alleles in that group of gene. Is responsible - for example - the variations in skin color.

7. What is a homozygous organism?
When the different alleles for a trait each code for enough protein so that - when they occur together - two different - normal proteins are made and show up in the organisms phenotype. For examples - blood types Ia - Ib - and Ia and Ib will be codom
Organisms that have two copies of the same allele
Means that a trait is expressed even if there is only one copy of the allele. Both sex linked and autosomal traits will be expressed if coded for by a dominant gene - regardless of the other copy of the gene on the homologous chromosome
The extent to which a given gene expresses itself in an individual or population

8. Dominant trait
Process that occurs between bacterial cells though cytoplasmic extensions that allow plasmids to move between cells.
Means that a trait is expressed even if there is only one copy of the allele. Both sex linked and autosomal traits will be expressed if coded for by a dominant gene - regardless of the other copy of the gene on the homologous chromosome
When bacteria pick up 'naked' DNA that has spilled out of lysed bacterial cells nearby or has been placed in a surrounding environment.
Small loops of dsDNA that exist within bacterial cells - but not as a part of the single - large chromosome.They replicate independently of the larger chromosome and can be freely exchanged from bacterial cell to bacterial cell via extensions of cyto

9. What is Conjugation?
Transduction - Transformation and Conjugation
Plasmids that contain antibiotic resistance genes - which code for enzymes that may break down or interfere with antibiotics.
Process that occurs between bacterial cells though cytoplasmic extensions that allow plasmids to move between cells.
1. When some genes normally contain terminal regions of C-A-G nucleotide repeats or other repeats that can extend up to 50 repeats long in normal - healthy individuals. 2. Huntingtons disease and the Fragile X Syndrome

10. What is the process of Transformation?

11. What are R-Plasmids?
1. Males and females are equally likely to have the trait 2. Traits do not skip generations 3. The trait is present if the corresponding gene is present 4. there is male to male and female - to - female transmission
The degree to which one expresses a trait depends upon the ratio of dominant to recessive alleles in that group of gene. Is responsible - for example - the variations in skin color.
1. All daughters of a male who has the trait will also have the trait 2. There is no male-to-male transmission 3. A female who has the trait may or may not pass on the affected X to her son or daughter (unless she has two affected X'S).
Plasmids that contain antibiotic resistance genes - which code for enzymes that may break down or interfere with antibiotics.

12. Recessive alleles when transcribed produce ___________ that cannot preform their given function
When a second gene determines whether a first gene is expressed or not.
Defective proteins
The different forms of a gene. Two copies may not be identical
That genes for one trait separate independent of genes for other traits. So - the variation of the different combinations you could get between Ww and Yy. Can find this out by doing a hybrid cross

13. What is an Operon?
When the different alleles for a trait each code for enough protein so that - when they occur together - two different - normal proteins are made and show up in the organisms phenotype. For examples - blood types Ia - Ib - and Ia and Ib will be codom
A functional unit of gene expression made up of several related genes - an operator and promoter
Process that occurs between bacterial cells though cytoplasmic extensions that allow plasmids to move between cells.
Males only have one X chromosomes in addition to their Y chromosome. If this X has the mutant gene on it - there is no normal gene to override. Female have a chance of having a normal gene on the other X that can produce enough normal protein that th

14. What is genetic anticipation?
In the nucleoid region
This is a genetic inheritance pattern that results from the fact that certain alleles seem to be encoded differently depending upon which parent the allele comes from.
The building up of a trait over the course of several generations.
The different forms of a gene. Two copies may not be identical

15. Define phenotype
Epigenesis
The physical features of an organism
1. Trait is far more common in males than in females 2. All daughters of a male who has the trait are heterozygous carriers 3. There is no male-to-male transmission 4. Mothers of males who have the trait are either heterozygous carriers or homozygous
When one'S cellular organelles derive entirely from the mother - all genes present in one'S organelles have a maternal - rather than paternal origin. Sperm contains no organelles that are transferred to the egg upon fertilization

16. Define Allele
When a second gene determines whether a first gene is expressed or not.
3 genes (lac Z - lac Y and lacA) - promoter region and an operator region. Function: responsible for the breakdown of lactose.
A functional unit of gene expression made up of several related genes - an operator and promoter
The different forms of a gene. Two copies may not be identical

17. What is Genomic Imprinting?
The building up of a trait over the course of several generations.
Males only have one X chromosomes in addition to their Y chromosome. If this X has the mutant gene on it - there is no normal gene to override. Female have a chance of having a normal gene on the other X that can produce enough normal protein that th
The degree to which one expresses a trait depends upon the ratio of dominant to recessive alleles in that group of gene. Is responsible - for example - the variations in skin color.
This is a genetic inheritance pattern that results from the fact that certain alleles seem to be encoded differently depending upon which parent the allele comes from.

18. What is a heterozygous organism?
Organisms that have one copy of a dominant allele and one recessive allele
3 genes (lac Z - lac Y and lacA) - promoter region and an operator region. Function: responsible for the breakdown of lactose.
Rediscovered mendels work to help figure out why traits were passed on in the patterns that he saw. Helped to discover the concept of gene linkage
Plasmids that contain antibiotic resistance genes - which code for enzymes that may break down or interfere with antibiotics.

19. When does Codominance occur?
When the different alleles for a trait each code for enough protein so that - when they occur together - two different - normal proteins are made and show up in the organisms phenotype. For examples - blood types Ia - Ib - and Ia and Ib will be codom
Transduction - Transformation and Conjugation
Organisms that have one copy of a dominant allele and one recessive allele
Plasmids that contain antibiotic resistance genes - which code for enzymes that may break down or interfere with antibiotics.

20. Males cannot be carriers of sex linked traits
Plasmids that contain antibiotic resistance genes - which code for enzymes that may break down or interfere with antibiotics.
The building up of a trait over the course of several generations.
Males only have one X chromosomes in addition to their Y chromosome. If this X has the mutant gene on it - there is no normal gene to override. Female have a chance of having a normal gene on the other X that can produce enough normal protein that th
This is a genetic inheritance pattern that results from the fact that certain alleles seem to be encoded differently depending upon which parent the allele comes from.

21. What is the Operon model?
The building up of a trait over the course of several generations.
The different forms of a gene. Two copies may not be identical
That genes for one trait separate independent of genes for other traits. So - the variation of the different combinations you could get between Ww and Yy. Can find this out by doing a hybrid cross
The model of how bacteria turn on and off genes

22. Define Penetrance
When bacteria pick up 'naked' DNA that has spilled out of lysed bacterial cells nearby or has been placed in a surrounding environment.
1. Incomplete dominance occurs when the dominant allele does not code for enough of a given protein. You see the full effect of the gene when two copies of the dominant allele are present in the cell. Like with flowers - 2 red alleles are red - 2 whi
The different forms of a gene. Two copies may not be identical
The extent to which a given gene expresses itself in an individual or population

23. Define Repressor Enzymes
The model of how bacteria turn on and off genes
Process that occurs between bacterial cells though cytoplasmic extensions that allow plasmids to move between cells.
Proteins that attaches to the operator sequence only when a certain compound is present in the environment
1. You have two copies of each chromosome - one from mom and one from dad. Also - 2 copies of each gene

24. Dominance has nothing to do with __________. Dominant alleles are not more common in populations than recessive alleles. Dominance is not an allele that overpowers a recessive allele.
The process by which viruses infect certain bacterial cells - allowing new baby viruses to trap bacterial genes. Can transfer DNA to new cells - which can integrate into the host cells chromosomes.
3 genes (lac Z - lac Y and lacA) - promoter region and an operator region. Function: responsible for the breakdown of lactose.
When bacteria pick up 'naked' DNA that has spilled out of lysed bacterial cells nearby or has been placed in a surrounding environment.
Frequency

25. What are characteristics of autosomal dominant traits?
This is a genetic inheritance pattern that results from the fact that certain alleles seem to be encoded differently depending upon which parent the allele comes from.
1. Males and females are equally likely to have the trait 2. Traits do not skip generations 3. The trait is present if the corresponding gene is present 4. there is male to male and female - to - female transmission
1. You have two copies of each chromosome - one from mom and one from dad. Also - 2 copies of each gene
Epigenesis

26. What are characteristics of X-Linked dominant traits?

27. What does the Law of Independent Assortment state?
That genes for one trait separate independent of genes for other traits. So - the variation of the different combinations you could get between Ww and Yy. Can find this out by doing a hybrid cross
In the nucleoid region
The physical features of an organism
RNA polymerase attaches to promoter sequence immediately prior to the gene that is to be transcribed - follows along the DNA strand - reading DNA into mRNA ? repressor protein (controlled by a regulatory gene) binds to operator not allowing RNA to mo

28. Describe how incomplete dominance occurs and what is it.
That two alleles for a given trait separate from each other during meiosis - and thus - end up in different sperm or egg cells. So an organism can pass on a W or a w from a set of Ww - but never both
1. Incomplete dominance occurs when the dominant allele does not code for enough of a given protein. You see the full effect of the gene when two copies of the dominant allele are present in the cell. Like with flowers - 2 red alleles are red - 2 whi
1. Trait is far more common in males than in females 2. All daughters of a male who has the trait are heterozygous carriers 3. There is no male-to-male transmission 4. Mothers of males who have the trait are either heterozygous carriers or homozygous
Organisms that have two copies of the same allele

29. What does it mean to be a diploid organism?
1. You have two copies of each chromosome - one from mom and one from dad. Also - 2 copies of each gene
When the different alleles for a trait each code for enough protein so that - when they occur together - two different - normal proteins are made and show up in the organisms phenotype. For examples - blood types Ia - Ib - and Ia and Ib will be codom
The process by which viruses infect certain bacterial cells - allowing new baby viruses to trap bacterial genes. Can transfer DNA to new cells - which can integrate into the host cells chromosomes.
That two alleles for a given trait separate from each other during meiosis - and thus - end up in different sperm or egg cells. So an organism can pass on a W or a w from a set of Ww - but never both

30. What are characteristics of autosomal recessive traits?
Organisms that have two copies of the same allele
1. Males and females are equally likely to have the trait 2. Traits often skip generations 3. only homozygous individuals have the trait 4. Traits can appear in siblings without appearing in parents 5. If a parent has the trait - those offspring who
When one'S cellular organelles derive entirely from the mother - all genes present in one'S organelles have a maternal - rather than paternal origin. Sperm contains no organelles that are transferred to the egg upon fertilization
1. When some genes normally contain terminal regions of C-A-G nucleotide repeats or other repeats that can extend up to 50 repeats long in normal - healthy individuals. 2. Huntingtons disease and the Fragile X Syndrome

31. What are plasmids?
1. Males and females are equally likely to have the trait 2. Traits do not skip generations 3. The trait is present if the corresponding gene is present 4. there is male to male and female - to - female transmission
Small loops of dsDNA that exist within bacterial cells - but not as a part of the single - large chromosome.They replicate independently of the larger chromosome and can be freely exchanged from bacterial cell to bacterial cell via extensions of cyto
Proteins that attaches to the operator sequence only when a certain compound is present in the environment
The model of how bacteria turn on and off genes

32. What is Transduction?
A functional unit of gene expression made up of several related genes - an operator and promoter
Frequency
The process by which viruses infect certain bacterial cells - allowing new baby viruses to trap bacterial genes. Can transfer DNA to new cells - which can integrate into the host cells chromosomes.
That two alleles for a given trait separate from each other during meiosis - and thus - end up in different sperm or egg cells. So an organism can pass on a W or a w from a set of Ww - but never both

33. What 3 ways do bacteria recombine genes and shuffle their gene pools from generation to generation in the absence of sexual reproduction?
3 genes (lac Z - lac Y and lacA) - promoter region and an operator region. Function: responsible for the breakdown of lactose.
Transduction - Transformation and Conjugation
The degree to which one expresses a trait depends upon the ratio of dominant to recessive alleles in that group of gene. Is responsible - for example - the variations in skin color.
Organisms that have one copy of a dominant allele and one recessive allele

34. In Bacteria - in what region of the cell is the DNA found?
The physical features of an organism
In the nucleoid region
That genes for one trait separate independent of genes for other traits. So - the variation of the different combinations you could get between Ww and Yy. Can find this out by doing a hybrid cross
1. When some genes normally contain terminal regions of C-A-G nucleotide repeats or other repeats that can extend up to 50 repeats long in normal - healthy individuals. 2. Huntingtons disease and the Fragile X Syndrome

35. What is the Triplet Repeat Extension? What diseases are caused by this?
When a second gene determines whether a first gene is expressed or not.
1. When some genes normally contain terminal regions of C-A-G nucleotide repeats or other repeats that can extend up to 50 repeats long in normal - healthy individuals. 2. Huntingtons disease and the Fragile X Syndrome
The building up of a trait over the course of several generations.
When bacteria pick up 'naked' DNA that has spilled out of lysed bacterial cells nearby or has been placed in a surrounding environment.

36. What is a Polygene?
1. Trait is far more common in males than in females 2. All daughters of a male who has the trait are heterozygous carriers 3. There is no male-to-male transmission 4. Mothers of males who have the trait are either heterozygous carriers or homozygous
When the different alleles for a trait each code for enough protein so that - when they occur together - two different - normal proteins are made and show up in the organisms phenotype. For examples - blood types Ia - Ib - and Ia and Ib will be codom
The degree to which one expresses a trait depends upon the ratio of dominant to recessive alleles in that group of gene. Is responsible - for example - the variations in skin color.
Epigenesis

37. Define genotype
1. Incomplete dominance occurs when the dominant allele does not code for enough of a given protein. You see the full effect of the gene when two copies of the dominant allele are present in the cell. Like with flowers - 2 red alleles are red - 2 whi
The different forms of a gene. Two copies may not be identical
Is the type of genes an organism has
That genes for one trait separate independent of genes for other traits. So - the variation of the different combinations you could get between Ww and Yy. Can find this out by doing a hybrid cross

38. When does Epistasis occur?
Epigenesis
The building up of a trait over the course of several generations.
Frequency
When a second gene determines whether a first gene is expressed or not.

39. Genomic Imprinting is also known by what other name?
Epigenesis
Is the type of genes an organism has
Means that a trait is expressed even if there is only one copy of the allele. Both sex linked and autosomal traits will be expressed if coded for by a dominant gene - regardless of the other copy of the gene on the homologous chromosome
1. All daughters of a male who has the trait will also have the trait 2. There is no male-to-male transmission 3. A female who has the trait may or may not pass on the affected X to her son or daughter (unless she has two affected X'S).

40. What are the parts of a lac operon? What is its function?
Frequency
Transduction - Transformation and Conjugation
1. Males and females are equally likely to have the trait 2. Traits do not skip generations 3. The trait is present if the corresponding gene is present 4. there is male to male and female - to - female transmission
3 genes (lac Z - lac Y and lacA) - promoter region and an operator region. Function: responsible for the breakdown of lactose.