BSC 2010 Lecture Notes - Lecture 8: X-Ray Crystallography, Erwin Chargaff, The Double Helix
Document Summary
Get access
Related Documents
Related Questions
1. | In addition to identifying the genetic material, the experiments of Avery, MacLeod, and McCarty with different strains of Streptococcus pneumoniae demonstrated that | ||||||||||
|
2. | In order to show that DNA in cell extracts is responsible for genetic transformation in Streptococcus pneumoniae, important corroborating evidence should indicate that _______ also destroy transforming activity. | ||||||||||
|
3. | Based on what you have learned about the experiments conducted by Griffith and Avery and colleagues with bacteria, which of the following would result in transformation of living R cells? | ||||||||||
|
4. | A-T base pairs in a DNA double helix | ||||||||||
|
5. | If 23 percent of the bases in a sample of double-stranded DNA are adenine, what percentage of the bases are uracil? | ||||||||||
|
6. | The uniform diameter of the DNA structure provides evidence for | ||||||||||
|
7. | If a sequence of one strand of DNA is 5â²-TGACTATC-3â², what is the complementary strand? | ||||||||||
|
8. | What structural aspect of the DNA facilitates dissociation of the two DNA strands for replication? | ||||||||||
|
9. | If the MeselsonâStahl density gradient experiment had resulted in two bands of DNA molecules after only one round of replication, one containing only 15N and the second only 14N, this result would have indicated that replication was | ||||||||||
|
10. | The nucleoside analogue acyclovir, which is used to treat herpes simplex virus (HSV) infections, lacks a 3â² hydroxyl group (âOH). Predict what will happen if the host cell DNA polymerase incorporates a molecule of acyclovir into an elongating strand of HSV DNA. | ||||||||||
|
11. | Which of the following does not demonstrate the stability of the DNA double helix? | ||||||||||
|
12. | What effect would a primase inhibitor have on DNA replication? | ||||||||||
|
13. | To replicate their DNA in a timely manner, most eukaryotic chromosomes | ||||||||||
|
14. | Which statement about DNA replication is false? | ||||||||||
|
15. | In many eukaryotes, there are repetitive sequences called telomeres at the ends of chromosomes. After successive rounds of DNA replication, the _______ strand becomes shorter. In some cells, an enzyme called _______ repairs the shortened strand. | ||||||||||
|
16. | A researcher studies normal human fibroblast cells. They can be maintained in culture but die off after about 30 cell generations. Unexpectedly, a colony of cells continues to survive and divide past 30 generations. Which scenario is most likely true for these cells? | ||||||||||
|
17. | If DNA polymerase III introduces an incorrect nucleotide, what is the first corrective action made by the DNA repair system? | ||||||||||
|
18. | Choose the correct order of the following four events in the excision repair of DNA: (1) Base-paired DNA is made complementary to the template. (2) Damaged bases are recognized. (3) DNA ligase seals the new strand to existing DNA. (4) Part of a single strand is excised. | ||||||||||
|
19. | Six complete cycles of PCR should result in a _______-fold increase in the amount of DNA. | ||||||||||
|
20. | When double-stranded DNA is heated to temperatures above 90°C, it denatures. Denaturation is a process that | ||||||||||
|
If an organismâs diploid chromosome number is 18, how many different possible combinations of homologous chromosomes lining up during meiosis exist for the eggs or sperm produced by that organism?
A. | 512 | |
B. | 9 | |
C. | 18 | |
D. | 128 | |
E. | 36 |
At the end of metaphase I, _______________ separate.
A. | sister chromatids | |
B. | germ cells | |
C. | homologous chromosomes | |
D. | haploid chromatids | |
E. | centrioles |
Mendel observed that dominant traits
A. | are seen in all of the F1 hybrid pea plants in his experiments. | |
B. | are expressed in all plants. | |
C. | were absent in the F1 generation of pea plants that he used in his experiments. | |
D. | were the only traits seen in the F2 generation of pea plants in his experiments. | |
E. | are only expressed in hybrids. |
Cytokinesis in plant cells differs from cytokinesis in animal cells because
A. | there is no difference. | |
B. | in plant cells, the cell plate must also divide into two parts. | |
C. | the contractile protein, actin, is important only in plant cells. | |
D. | plant cells have a rigid cell wall. | |
E. | a contractile ring forms only in plant cells. |
Sickle cell anemia is an example of what type of inheritance?
A. | complete dominance | |
B. | incomplete dominance | |
C. | codominance | |
D. | multiple alleles | |
E. | recessive dominance |
Which of the following statements is true:
A. | The dominant allele is masked in homozygous dominant individuals. | |
B. | With recessive genetic disorders, if both parents are carriers, the offspring will all be affected. | |
C. | In carriers, the recessive allele causes an intermediate phenotype. | |
D. | In recessive genetic disorders, the mother and/or father of an affected individual must also be affected. | |
E. | With dominant genetic disorders, the mother and/or father of an affected individual must also be affected. |
Skin cancers typically develop in the
A. | upper layers of the epidermis. | |
B. | lower layers of the dermis. | |
C. | subcutaneous layer. | |
D. | lower layers of the epidermis. | |
E. | upper layers of the dermis. |
Duchenne muscular dystrophy (MD) is inherited from an X-linked recessive allele. What is the probability that a son with Duchenne MD inherited this disease from his biological father?
A. | 1/2 | |
B. | 0 | |
C. | 1/16 | |
D. | 1/4 | |
E. | 1/8 |
The genetic makeup of a particular trait in an individual is its
A. | genotype. | |
B. | heterozygosity. | |
C. | phenotype. | |
D. | filial. | |
E. | dominance. |
What structure holds the sister chromatids to the spindle fibers?
A. | chromatin | |
B. | kinetochore | |
C. | MPF | |
D. | centromere | |
E. | cyclin |
If you view a cell in which the genetic material is beginning to be visible as separate bodies, and the nucleus has disappeared from view, you may surmise that the cells is in
A. | telophase. | |
B. | anaphase. | |
C. | interphase. | |
D. | metaphase. | |
E. | prophase. |
Gregor Mendel was successful in his analysis of the genetics of pea plants because
A. | he examined and analyzed both the F1 and F2 generations. | |
B. | he studied the parental plants to determine their differences. | |
C. | he decided to only look at his results in an objective manner. | |
D. | he studied a trait that had a strange inheritance pattern. | |
E. | pea plants have genetics different from other organisms. |
Tall corn plants (T) are dominant to dwarf plants (tt). Solid green leaves (G) are dominant to leaves with a white tip (gg). A cross between two corn plants yielded the following phenotypes: 51 tall plants with a white tip on their leaves; 43 dwarf plants with solid leaves; 48 dwarf plants with white tips on their leaves; 45 tall plants with solid leaves. What are the genotypes of the parents that produced these plants?
A. | None of the above | |
B. | TtGg x Ttgg | |
C. | ttGG x TTgg | |
D. | TtGg x TtGg | |
E. | TtGg x ttgg |
In humans, a gene that has been identified as causing a type of skin cancer is the
A. | superwoman echidna. | |
B. | mutant superman. | |
C. | sonic hedgehog. | |
D. | mutant mole rat. | |
E. | superhero aardvark. |
The segregation principle states that in sexually reproducing diploid organisms the two copies of each gene
A. | segregate from each other during meiosis. | |
B. | must always be the same allele. | |
C. | separate from each other during mitosis. | |
D. | will both wind up in either the sperm or egg. | |
E. | move together as a unit during meiosis. |
In what phases is the genetic material in the cell correctly referred to as chromatids?
A. | metaphase and telophase | |
B. | anaphase and metaphase | |
C. | interphase and telophase | |
D. | interphase and prophase | |
E. | metaphase and prophase |
Consider two traits for an organism, determined by two genes, each of which is governed by at least two alleles. In the case of a dihybrid individual, the gametes formed will be of either the parental type or the recombinant type. Recombinant type gametes are formed because of
A. | the principle of dihybrids. | |
B. | multiple alleles. | |
C. | heterozygosity. | |
D. | incomplete dominance. | |
E. | independent assortment. |
An allele is
A. | an alternate form of a gene. | |
B. | always recessive. | |
C. | the main factor determining a trait. | |
D. | always one of a pair. | |
E. | the dominant form of a gene. |
After the DNA is replicated, and it condenses in prophase, two identical rods of DNA are seen. These are
A. | spindle fibers. | |
B. | kinetochores. | |
C. | chromatids. | |
D. | chromatin. | |
E. | centromeres. |
Special cells found in the gonads that give rise to gametes upon division are called
A. | egg cells. | |
B. | somatic cells. | |
C. | germ cells. | |
D. | stem cells. | |
E. | basal cells. |
Q:
If an organismâs diploid chromosome number is 18, how many different possible combinations of homologous chromosomes lining up during meiosis exist for the eggs or sperm produced by that organism?
A. | 512 | |
B. | 9 | |
C. | 18 | |
D. | 128 | |
E. | 36 |
At the end of metaphase I, _______________ separate.
A. | sister chromatids | |
B. | germ cells | |
C. | homologous chromosomes | |
D. | haploid chromatids | |
E. | centrioles |
Mendel observed that dominant traits
A. | are seen in all of the F1 hybrid pea plants in his experiments. | |
B. | are expressed in all plants. | |
C. | were absent in the F1 generation of pea plants that he used in his experiments. | |
D. | were the only traits seen in the F2 generation of pea plants in his experiments. | |
E. | are only expressed in hybrids. |
Cytokinesis in plant cells differs from cytokinesis in animal cells because
A. | there is no difference. | |
B. | in plant cells, the cell plate must also divide into two parts. | |
C. | the contractile protein, actin, is important only in plant cells. | |
D. | plant cells have a rigid cell wall. | |
E. | a contractile ring forms only in plant cells. |
Sickle cell anemia is an example of what type of inheritance?
A. | complete dominance | |
B. | incomplete dominance | |
C. | codominance | |
D. | multiple alleles | |
E. | recessive dominance |
Which of the following statements is true:
A. | The dominant allele is masked in homozygous dominant individuals. | |
B. | With recessive genetic disorders, if both parents are carriers, the offspring will all be affected. | |
C. | In carriers, the recessive allele causes an intermediate phenotype. | |
D. | In recessive genetic disorders, the mother and/or father of an affected individual must also be affected. | |
E. | With dominant genetic disorders, the mother and/or father of an affected individual must also be affected. |
Skin cancers typically develop in the
A. | upper layers of the epidermis. | |
B. | lower layers of the dermis. | |
C. | subcutaneous layer. | |
D. | lower layers of the epidermis. | |
E. | upper layers of the dermis. |
Duchenne muscular dystrophy (MD) is inherited from an X-linked recessive allele. What is the probability that a son with Duchenne MD inherited this disease from his biological father?
A. | 1/2 | |
B. | 0 | |
C. | 1/16 | |
D. | 1/4 | |
E. | 1/8 |
The genetic makeup of a particular trait in an individual is its
A. | genotype. | |
B. | heterozygosity. | |
C. | phenotype. | |
D. | filial. | |
E. | dominance. |
What structure holds the sister chromatids to the spindle fibers?
A. | chromatin | |
B. | kinetochore | |
C. | MPF | |
D. | centromere | |
E. | cyclin |
If you view a cell in which the genetic material is beginning to be visible as separate bodies, and the nucleus has disappeared from view, you may surmise that the cells is in
A. | telophase. | |
B. | anaphase. | |
C. | interphase. | |
D. | metaphase. | |
E. | prophase. |
Gregor Mendel was successful in his analysis of the genetics of pea plants because
A. | he examined and analyzed both the F1 and F2 generations. | |
B. | he studied the parental plants to determine their differences. | |
C. | he decided to only look at his results in an objective manner. | |
D. | he studied a trait that had a strange inheritance pattern. | |
E. | pea plants have genetics different from other organisms. |
Tall corn plants (T) are dominant to dwarf plants (tt). Solid green leaves (G) are dominant to leaves with a white tip (gg). A cross between two corn plants yielded the following phenotypes: 51 tall plants with a white tip on their leaves; 43 dwarf plants with solid leaves; 48 dwarf plants with white tips on their leaves; 45 tall plants with solid leaves. What are the genotypes of the parents that produced these plants?
A. | None of the above | |
B. | TtGg x Ttgg | |
C. | ttGG x TTgg | |
D. | TtGg x TtGg | |
E. | TtGg x ttgg |
In humans, a gene that has been identified as causing a type of skin cancer is the
A. | superwoman echidna. | |
B. | mutant superman. | |
C. | sonic hedgehog. | |
D. | mutant mole rat. | |
E. | superhero aardvark. |
The segregation principle states that in sexually reproducing diploid organisms the two copies of each gene
A. | segregate from each other during meiosis. | |
B. | must always be the same allele. | |
C. | separate from each other during mitosis. | |
D. | will both wind up in either the sperm or egg. | |
E. | move together as a unit during meiosis. |
In what phases is the genetic material in the cell correctly referred to as chromatids?
A. | metaphase and telophase | |
B. | anaphase and metaphase | |
C. | interphase and telophase | |
D. | interphase and prophase | |
E. | metaphase and prophase |
Consider two traits for an organism, determined by two genes, each of which is governed by at least two alleles. In the case of a dihybrid individual, the gametes formed will be of either the parental type or the recombinant type. Recombinant type gametes are formed because of
A. | the principle of dihybrids. | |
B. | multiple alleles. | |
C. | heterozygosity. | |
D. | incomplete dominance. | |
E. | independent assortment. |
An allele is
A. | an alternate form of a gene. | |
B. | always recessive. | |
C. | the main factor determining a trait. | |
D. | always one of a pair. | |
E. | the dominant form of a gene. |
After the DNA is replicated, and it condenses in prophase, two identical rods of DNA are seen. These are
A. | spindle fibers. | |
B. | kinetochores. | |
C. | chromatids. | |
D. | chromatin. | |
E. | centromeres. |
Special cells found in the gonads that give rise to gametes upon division are called
A. | egg cells. | |
B. | somatic cells. | |
C. | germ cells. | |
D. | stem cells. | |
E. | basal cells. |