bio14 test review

18.Animals that possess homologous structures probably _____.

evolved from the same ancestor

15. Which of the following is not true of RNA processing? -Exons are cut out before mRNA leaves the nucleus. -RNA splicing can be catalyzed by spliceosomes. -A primary transcript is often much longer than the final RNA molecule that leaves the nucleus. -Nucleotides may be added at both ends of the RNA. -Ribozymes may function in RNA splicing.

Exons are cut out before mRNA leaves the nucleus.

________________is the movement of genetic material from the environment into a cell.

Transformation

The anticodon of a particular tRNA molecule is

complementary to the corresponding mRNA codon

Which of the following evolutionary forces can introduce new genetic variation into a population?

mutation and gene flow

18.In two related species of fish, one reproduces only in cold water, while the other only reproduces in warm water. This is an example of a:

prezygotic barrier.

15. Which component is not directly involved in translation?

DNA

Which branch point on the phylogenetic tree represents the most recent common ancestor of chickens and frogs?

3

14) Which of the following must exist in a population before natural selection can act upon that population?

A) genetic variation among individuals

Scientists divide organisms into which Three Domains of Life?

Bacteria, Archaea, Eukarya

18.Imagine you have discovered a new lizard that lives in a foggy desert in southwestern South America. As fog rolls in, this lizard stands on its head and lets water condense on its back and roll in grooves to its mouth. Considering the similar behavior of the Namibian beetle (from Namibia, Africa) in the figure below, this trait is an example of which of the following?

Convergent evolution

15. The final product of an expressed gene can be which of the following? Find all of the correct choices. a) mRNA b) tRNA c) rRNA d) polypeptide

D) polypeptide The entire process is called gene expression. In translation, messenger RNA (mRNA) is decoded in a ribosome to produce a specific amino acid chain, or polypeptide. The polypeptide later folds into an active protein and performs its functions in the cell.

14.A biochemist isolates, purifies, and combines in a test tube a variety of molecules needed for DNA replication. When she adds some DNA to the mixture, replication occurs, but each DNA molecule consists of a normal strand paired with numerous segments of DNA a few hundred nucleotides long. What has she probably left out of the mixture?

DNA Ligase

he frequency of dark peppered moths in England during the Industrial Revolution increased. This is an example of:

Directional selection

14.Although the proteins that cause E. coli chromosomes to coil are not histones, what property would you expect them to share with histones given their ability to bind to DNA,

Expected to contain many basic (positively charged) amino acids which can form weak bonds with the negatively charged phosphate groups on the sugar-phosphate back bone of the DNA molecule.

6) ________________is the movement of genetic material from one species to anothe

Horizontal gene transfer

15. Which of the following is not true of a codon? -It may code for the same amino acid as another codon. -It consists of three nucleotides. -It never codes for more than one amino acid. -It extends from one end of a tRNA molecule. -It is the basic unit of the genetic code.

It extends from one end of a tRNA molecule.

Which population would be more likely to be affected by genetic drift?

Snails on an island in the Mississippi River

18.Two species of birds have different mating songs and so do not interbreed. This is an example of:

behavioral isolation

A species of flower on an island has individuals with red flowers and some with white flowers. After a hurricane, only red flowered plants remain, thus demonstrating

bottleneck

Which type of selection results in greater genetic variance in a population?

diversifying selection

14. The elongation of the leading strand during DNA synthesis: a. progresses away from the replication fork b. occurs in the 3' to 5' direction c. produces Okazaki fragments d. depends on the action of DNA polymerase e. does not require a template strand

e. does not require a template strand

4) A new allele can be introduced to a population by either a mutation or

genetic drift

What do scientists use to apply cladistics?

homologous traits

Population genetics is the study of

how selective forces change the allele frequencies in a population over time

) The scientific field in which information is used to classify organisms based on evolutionary relationships is known as

phylogenetic tree

18.When hybrids between two newly formed species are weak, this results in a continuation of species separation termed:

reinforcement

18.Two closely related species remain separate but occasionally produce healthy hybrids. This situation would be classified as

stability.

14. The leading and the lagging strands differ in that...

the leading strand is synthesized in the same direction as the movement of the replication fork, and the lagging strand is synthesized in the opposite direction

18. What is Sympatric Speciation?

the process through which new species evolve from a single ancestral species while inhabiting the same geographic region

15. What is the promoter?

the promoter is the region of DNA to which RNA polymerase binds to begin transcription

14._______________ creates temporary nicks in DNA that prevents DNA from supercoiling ahead of the replication fork.

topoisomerase