PLS170C1 Exam 2 Questions with
Correct Answers
What constitutes an individual's genome? - Answer-all of its DNA
A particular protein is 400 amino acids long. How many nucleotides in the template
strand of DNA are required to code for this protein? - Answer-1200
When examining the genetic code, it is apparent that ____________________. -
Answer-There can be more than one codon for a particular amino acid
The relationship between a gene and a messenger RNA is as follows: - Answer-mRNAs
are made from genes.
Making a complementary copy of the genetic code in DNA by synthesis of RNA is called
________________________. - Answer-transcription
___________________ refers to converting the codons in RNA to an amino acid
sequence of a protein. - Answer-Translation
Which of the following is the correct RNA sequence for the DNA sequence
GCCATAAGT? - Answer-CGGUAUUCA
The anticodon is found on the ________________ which is essential for converting
codons on mRNA to an amino acid sequence of proteins. - Answer-tRNA
Heritable changes in the DNA of an organism are referred to as _____________. -
Answer-mutations
The original source of all genetic variation is ___________________. - Answer-mutation
What is meant by a paternal chromosome? - Answer-the member of a homologous pair
that was inherited from the father
Crossing over during prophase I of meiosis usually contributes to genetic variation by
exchanging chromosomal segments between _______________. - Answer-homologous
chromosome pairs
How many different combinations of maternal and paternal chromosomes can be
packaged in gametes made by an organism with a diploid chromosome number of 6 (2n
= 6)? - Answer-8
, Genetic variation, provided through sexual reproduction, offers more opportunity for
offspring to survive in changing environments. What two aspects of meiosis provide
sources of such variation? - Answer-crossing over and independent assortment of
chromosomes
What is genetic recombination? - Answer-the new combination of maternal and paternal
chromosome segments that result when homologs cross over
A farmer uses triazine herbicide to control pigweed in his field. For the first few years,
the triazine works well and almost all the pigweed dies; but after several years, the
farmer sees more and more pigweed. Which of these explanations best describes this
observation? - Answer-Only triazine-resistant weeds survived and reproduced, so each
year more pigweed was triazine-resistant.
Resistance to a wide variety of insecticides, fungicides, antibiotics, antiviral drugs, and
herbicides has recently evolved in hundreds of insects, fungi, bacteria, viruses, and
plants. Why? - Answer-Humans are altering the environments of these organisms, and
the organisms are evolving by natural selection.
________________ is defined as the tendency of organisms that have favorable
adaptations to their environment to survive to reproduce. - Answer-Natural selection
Which environmental influences are likely to have caused the evolution of
developmental changes in early primitive plant species? - Answer-Presence of
herbivores, Rainfall, Temperature
Which environmental influences are NOT likely to have caused the evolution of
developmental changes in early primitive plant species? - Answer-Chemicals released
by human pollution
Radioisotopes are often used to determine the time of death of fossilized remains.
Tritium has a half-life of 12.3 years. That means that 24.6 years after an organism dies
it will have _______ of the original radioactive tritium. - Answer-1/4
What types of plants would you NOT expect to see during a walk in a forest about 250
million years ago? - Answer-Flowering Plants
Evolution of species on Earth _____________________. - Answer-has occurred
throughout Earth's history and is still under way.
A gene pool consists of all the alleles ___________________. - Answer-present in a
specific population
Evolution occurs at the level of ________________________. - Answer-The Population
Correct Answers
What constitutes an individual's genome? - Answer-all of its DNA
A particular protein is 400 amino acids long. How many nucleotides in the template
strand of DNA are required to code for this protein? - Answer-1200
When examining the genetic code, it is apparent that ____________________. -
Answer-There can be more than one codon for a particular amino acid
The relationship between a gene and a messenger RNA is as follows: - Answer-mRNAs
are made from genes.
Making a complementary copy of the genetic code in DNA by synthesis of RNA is called
________________________. - Answer-transcription
___________________ refers to converting the codons in RNA to an amino acid
sequence of a protein. - Answer-Translation
Which of the following is the correct RNA sequence for the DNA sequence
GCCATAAGT? - Answer-CGGUAUUCA
The anticodon is found on the ________________ which is essential for converting
codons on mRNA to an amino acid sequence of proteins. - Answer-tRNA
Heritable changes in the DNA of an organism are referred to as _____________. -
Answer-mutations
The original source of all genetic variation is ___________________. - Answer-mutation
What is meant by a paternal chromosome? - Answer-the member of a homologous pair
that was inherited from the father
Crossing over during prophase I of meiosis usually contributes to genetic variation by
exchanging chromosomal segments between _______________. - Answer-homologous
chromosome pairs
How many different combinations of maternal and paternal chromosomes can be
packaged in gametes made by an organism with a diploid chromosome number of 6 (2n
= 6)? - Answer-8
, Genetic variation, provided through sexual reproduction, offers more opportunity for
offspring to survive in changing environments. What two aspects of meiosis provide
sources of such variation? - Answer-crossing over and independent assortment of
chromosomes
What is genetic recombination? - Answer-the new combination of maternal and paternal
chromosome segments that result when homologs cross over
A farmer uses triazine herbicide to control pigweed in his field. For the first few years,
the triazine works well and almost all the pigweed dies; but after several years, the
farmer sees more and more pigweed. Which of these explanations best describes this
observation? - Answer-Only triazine-resistant weeds survived and reproduced, so each
year more pigweed was triazine-resistant.
Resistance to a wide variety of insecticides, fungicides, antibiotics, antiviral drugs, and
herbicides has recently evolved in hundreds of insects, fungi, bacteria, viruses, and
plants. Why? - Answer-Humans are altering the environments of these organisms, and
the organisms are evolving by natural selection.
________________ is defined as the tendency of organisms that have favorable
adaptations to their environment to survive to reproduce. - Answer-Natural selection
Which environmental influences are likely to have caused the evolution of
developmental changes in early primitive plant species? - Answer-Presence of
herbivores, Rainfall, Temperature
Which environmental influences are NOT likely to have caused the evolution of
developmental changes in early primitive plant species? - Answer-Chemicals released
by human pollution
Radioisotopes are often used to determine the time of death of fossilized remains.
Tritium has a half-life of 12.3 years. That means that 24.6 years after an organism dies
it will have _______ of the original radioactive tritium. - Answer-1/4
What types of plants would you NOT expect to see during a walk in a forest about 250
million years ago? - Answer-Flowering Plants
Evolution of species on Earth _____________________. - Answer-has occurred
throughout Earth's history and is still under way.
A gene pool consists of all the alleles ___________________. - Answer-present in a
specific population
Evolution occurs at the level of ________________________. - Answer-The Population
