Biology Exam Wilkerson
Unlock all answers in this set
Unlock answersquestion
Each pea-plant gamete has how many alleles for the height gene?
answer
1
question
The different forms of a gene are called
answer
alleles
question
Gregor Mendel removed the male parts from the flowers of some plants in order to
answer
control crosses between plants
question
If a pea plant has a recessive allele for green peas, it will produce
answer
green peas if it does not also have a dominant allele for yellow peas
question
When Gregor Mendel crossed a tall pea plant with a short plant, the F1 plants inherited
answer
one allele from each parent
question
If pea plant's alleles for height are tt, what is true of its parents?
answer
Both parents contributed a recessive allele
question
When Gregor Mendel crossed true-breeding tall plants with true-breeding short plants, why was it impossible to observe segregation?
answer
Alleles in the F1 must be Tt to have height variety in the F2
question
A tall plant (TT) is crossed with a short plant (tt). If the tall F1 pea plants are allowed to self-pollinate,
answer
the offspring can be tall or short.
question
In the P generation, a tall plant was crossed with a short plant. Short plants reappeared in the F2 generation because
answer
the alleles for both heights segregated when the F1 plants made gametes.
question
When you flip a coin, what is the probability that it will come up on tails?
answer
1/2
question
The principles of probability can be used to
answer
predict the traits of the offspring of genetic crosses.
question
A heterozygous tall pea plant is crossed with a short pea plant. The probability that an F1 plant will be tall is
answer
50%
question
Organisms that have two identical alleles for a particular trait are said to be
answer
homozygous.
question
In the Punnett square shown in figure 11-1, which of the following is true about the offspring resulting from the cross?
answer
All are expected to be tall
question
What principle states that during gamete formation genes for different traits separate without influencing each other's inheritance?
answer
principle of independent assortment
question
Gregor Mendel's principles of genetics apply to
answer
all organisms.
question
Why did Thomas Hunt Morgan use fruit flies in his studies?
answer
Fruit flies produce a large number of offspring.
question
Roan cattle show codominance for the color of their hair. There are alleles for red hair and white hair. What would you expect a heterozygous roan bull to look like if the trait showed incomplete dominance instead?
answer
It would be pink
question
A breed of chicken shows codominance for feather color. One allele codes for black feathers, another codes for white feathers. The feathers of heterozygous chickens of this breed will be
answer
speckled.
question
Situations in which one allele for a gene is not completely dominant over another allele for that gene are called
answer
incomplete dominance.
question
In rabbits, there are four different versions of the gene for coat color. What pattern of inheritance is this?
answer
multiple alleles.
question
Variation in human skin color is an example of
answer
polygenic traits.
question
What determines the color of western white butterflies?
answer
temperature and genes
question
Which of the following supports the claim that the environment can affect genetic traits?
answer
Hydrangea flower color varies with soil pH.
question
The arctic fox is blue-gray in the summer and white in the winter. What most likely influence(s) this change?
answer
genes and the environment
question
The number of chromosomes in a gamete is represented by the symbol
answer
N.
question
If an organism's diploid number is 12, its haploid number is
answer
6.
question
Gametes have
answer
one allele for each gene.
question
Gametes are produced by the process of
answer
meiosis.
question
What is shown in Figure 11-4?
answer
crossing-over
question
Unlike mitosis, meiosis results in the formation of
answer
haploid cells.
question
What is formed at the end of meiosis?
answer
four genetically different cells
question
Which of the following assort independently? chromosomes linked genes multiple alleles codominant alleles
answer
chromosomes
question
Which bacteria killed the mice in Griffith's transformation experiment?
answer
live, harmless bacteria and heat-killed, harmful bacteria
question
Griffith called the process he observed transformation because
answer
the harmless bacteria had been transformed.
question
What did Avery conclude caused transformation?
answer
DNA was the transforming factor.
question
What happened when Griffith injected mice with the harmless, R-strain bacteria alone?
answer
The mouse lived.
question
Griffith's experiments advanced the study of genetics by proving that
answer
there is a chemical that contains genetic information that can be passed from one organism to another.
question
What is inside a bacteriophage?
answer
nucleic acid.
question
What so bacteriophages infect?
answer
bacteria.
question
Which part of the bacteriophage in Figure 12-1 contains genetic material?
answer
the inside of the "head"
question
What stores information in a cell?
answer
DNA
question
What happens when a piece of DNA is missing?
answer
Genetic information is lost.
question
In what way is DNA like a book?
answer
DNA has stored information, that can be copied and passed on.
question
In which cells is the accurate transmission of information most important?
answer
sex cells
question
Figure 12-2 shows the structure of
answer
a DNA molecule.
question
Which of the following is a nucleotide found in DNA?
answer
deoxyribose + phosphate group + cytosine
question
Because of base pairing in DNA, the percentage of
answer
thymine molecules in DNA is about equal to the percentage of adenine molecules.
question
The table in Figure 12-3 shows the result of measuring the percentages of the four bases in the DNA of several different organisms. Some of the values are missing from the table. Based on Chargaff's rule, the percentages of guanine bases in chicken DNA should be around
answer
21.5%
question
Based on Chargaff's rule, the percentage of cytosine in the DNA of the Bacterium, S. Lutea in Figure 12-3 should be around
answer
36.6%
question
What structural problem prevents adenine from pairing with guanine?
answer
The bases are both long.
question
DNA makes a good molecule for storing information because
answer
its bases can be joined together in any order, like the letters of the alphabet can be strung to form different words.
question
Which of the following best describes Rosalind Franklin's contribution to our understanding of the structure of DNA?
answer
She purified large amounts of DNA, stretched the fibers so the strands were parallel, and used an X-ray beam to produce an image of the molecule.
question
Rosalind Franklin contributed to the understanding of DNA by
answer
producing images of DNA molecules using X-rays.
question
Which of the following statements correctly describes Chargaff's contribution to the study of DNA?
answer
Chargaff showed that adenine and thymine were found in equal percentages in DNA, but he did not know this was because of base-pairing.
question
Which scientist(s) figured out that the shape of a DNA molecule is a double helix?
answer
Watson and Crick
question
Which scientist made x-ray diffraction photos of DNA?
answer
Franklin
question
The table in Figure 12-4 shows the percentages of bases in a DNA sample. How much Thymine should you expect to find in the sample? A C G T 22 - 28 -
answer
22%
question
What would happen to the percentage of G in Figure 12-4 if the percentage of A rose to 25%? A C G T 22 - 28 -
answer
G would drop to 25%
question
Which of the following forms a base pair with thymine?
answer
adenine
question
What did Rosalind Franklin contribute to the effort to identify the structure of DNA?
answer
x-ray diffraction photos of the DNA molecule
question
Watson and Crick discovered the two strands in DNA
answer
run in opposite directions.
question
DNA replication results in two DNA molecules,
answer
each with one new strand and one original strand.
question
During DNA replication, a DNA strand that had the bases CTAGGT produces a strand with the bases
answer
GATCCA.
question
What enzyme works to add DNA to ends of chromosomes in rapidly dividing cells such ass those found in an embryo, to prevent genes from being lost during replication?
answer
chromatin
question
In Figure 12-5, what nucleotide is going to be added at point 1, opposite from thymine?
answer
adenine
question
In Figure 12-5, what is adding base pairs to the strand?
answer
DNA polymerase
question
In eukaryotes, DNA
answer
is located in the nucleus.
question
Which would be greater in a eukaryote than in a prokaryote?
answer
The number of replication forks on a strand of DNA.
question
In both prokaryotes and eukaryotes, how many copies of the chromosome are left after replication?
answer
2
question
In both prokaryotes and eukaryotes, DNA replication happens
answer
before cell division.
question
RNA contains the sugar
answer
ribose.
question
Unlike DNA, RNA contains
answer
uracil.
question
Which of the following are found in both DNA and RNA?
answer
phosphate groups, guanine and cytosine
question
Which nucleotide in Figure 13-1 indicates the nucleic acid above is RNA?
answer
uracil
question
Which of the following is true? RNA is usually single-stranded. DNA is usually single-stranded. DNA contains uracil. RNA contains thymine.
answer
RNA is usually single-stranded.
question
Which type of RNA brings the information in the genetic code from the nucleus to other parts to the cell?
answer
mRNA
question
Which molecules are involved in protein synthesis?
answer
messenger RNA, ribosomal RNA, and transfer RNA
question
From which are mRNA molecules transcribed?
answer
DNA
question
What is produced during transcription?
answer
RNA molecules
question
During eukaryotic transcription, an RNA molecule is formed that is
answer
complementary to part of the strand of DNA.
question
What does Figure 13-2 show?
answer
the genetic code
question
How many nucleotides are needed to specify three amino acids?
answer
9
question
There are 64 codons and 20 amino acids. Which of the following is true?
answer
Several different codons can specify the same amino acid.
question
In Figure 13-3, which amino acid is specified by the mRNA code CCC?
answer
Pro
question
According to Figure 13-3, which code specifies the same amino acid as UAU?
answer
UAC
question
What happens during translation?
answer
The cell uses a messenger RNA code to make proteins.
question
During translation, the type of amino acid that is added to the growing polypeptide depends on the
answer
codon on the mRNA and the anticodon on the tRNA.
question
A protein is being assembled when
answer
RNA is being translated.
question
Genes contain instructions for assembling
answer
proteins.
question
Which is the correct sequence of the transfer of information in most organisms?
answer
DNA to RNA to protein
question
A mutation that involves one or a few nucleotides is called
answer
a point mutation.
question
Which of the following is a chromosomal mutation?
answer
inversion
question
When a chromosome undergoes a deletion mutation, information is
answer
lost.
question
What are some characteristics of polyploidy plant?
answer
They tend to be bigger and stronger than diploid plants.
question
Darwin noticed that many organisms seemed well suited to
answer
surviving in the environments in which they lived.
question
The species of finches that Charles Darwin found on different Galapagos Islands varied in certain structural adaptions. One of the most significant adaptions that Darwin noted was the
answer
birds' different-shaped beaks.
question
Based on the adaptions Charles Darwin observed in finches and tortoises in the Galapagos, he wondered
answer
if species living on different islands had once been members of the same species.
question
Biologists in Darwin's time had already begun to understand that living things change over time. How did Darwin contribute to these ideas?
answer
He figured out and explained how these changes happened and supported his ideas with evidence.
question
Charles Darwin's observation that finches of different species on the Galapagos Islands have many similar physical characteristics supports the hypothesis that these finches
answer
descended from a common ancestor.
question
On the Galapagos Island, Charles Darwin observed
answer
species similar to mainland South America species.
question
Which of the following ideas is supported by Darwin's observation of local variation among tortoises in the Galapagos Island?
answer
adaptation
question
People of Charles Darwin's time understood that fossils were
answer
preserved remains of ancient organisms.
question
James Hutton's and Charles Lyell's work suggests that
answer
Earth is several million years old.
question
In the 1800s, Charles Lyell emphasized that
answer
past geological events must be explained in terms of processes observable today.
question
One scientist who attempted to explain how rock formations, such as rock layers, form and change over time was
answer
James Hutton
question
James Hutton's and Charles Lyell's work was important to Darwin because these scientist
answer
suggested that Earth was old enough for evolution to have occurred.
question
What did Charles Darwin learn from reading the work of James Hutton and Charles Lyell?
answer
Gradual change operating over long periods of time can result in dramatic changes.
question
The economist Thomas Malthus suggested that
answer
without certain checks on population size, there would soon be insufficient food for the growing human population.
question
The idea that events like war, starvation, and disease could prevent the endless growth of human populations was presented by
answer
Thomas Malthus.
question
Darwin realized that the economist Malthus's theory of population control
answer
could be generalized to any population of organisms.
question
When a dairy farmer chooses to breed the cows that give the most milk in the here, the farmers are following the principle of
answer
artificial selection.
question
When a farmer breeds only his or her best livestock, the process involved is
answer
artificial selection.
question
According to Darwin's theory of natural selection, individuals who survive are the ones best adapted for their environment. Their survival is due to the
answer
possession of inherited adaptions that maximize fitness.
question
Which statement about the members of a population that live long enough to reproduce is consistent with the theory of evolution by natural selection?
answer
They are the ones that are best adapted to survive in their environment.
question
Charles Darwin called the ability of an organism to survive and reproduce in its specific environment
answer
fitness.
question
According to Darwin's theory of natural selection, the individuals that tend to survive are those that have
answer
variations best suited to environmental conditions.
question
Which of the following phrases best describes the results of natural selection?
answer
changes in the inherited characteristics of a population over time
question
Which statement is part of Darwin's theory of evolution by natural selection?
answer
More offspring are produced than can possibly survive.
question
Biogeography is the study of
answer
where species and their ancestors live.
question
Charles Darwin viewed the fossil record as
answer
useful support for his theory.
question
Which characteristic of Galapagos finches helped the Grants show the results of natural selection?
answer
the size and shape of their beaks
