Biology B Final Review
During which phase of meiosis do homologous chromosomes align as tetrads in the middle of the spindle?
A. prophase I
B. prophase II
C. metaphase I
D. metaphase II
The tall allele, T, is dominant to the short allele, t, in Mendel’s pea plants. You examine a pea plant what exhibits the tall phenotype. What is its genotype?
A. Tt
B. TT
C. tt
D. A and B are both possible.
Which was concluded by Mendel as a result of his genetic research?
A. Factors for different traits are inherited together as a matched pair.
B. Polyploidy can be beneficial in agriculture.
C. Factors for different traits are inherited independently of one another.
D. Meiosis occurs in two steps, meiosis I and meiosis II.
After performing a monohybrid cross, it is important to analyze the results with a Punnett square. What does each box in a Punnett square represent?
A. possible phenotype
B. possible genotype
C. one individual
D. two possible genotypes
What process is taking place in the illustration shown below?
A. fertilization
B. prophase II
C. polyploidy
D. crossing over
Which statement best explains the significance of meiosis in helping to maintain continuation of a species?
A. Meiosis produces eggs and sperm that are alike.
B. Meiosis provides for chromosomal variation in the gametes produced by an organism.
C. Equal numbers of eggs and sperm are produced by meiosis.
D. The gametes produced by meiosis ensure the continuation of any
A researcher crosses the F1 generation of two snapdragon plants. According to this information and the diagram below, what is the ratio of their offspring (F2)?
A. 0 red; 4 pink; 0 white
B. 1 red; 2 pink; 1 white
C. 3 red; 0 pink; 1 white
D. 4 red; 0 pink; 0 white
A molecule of DNA is made up of______.
A. amino acids and proteins
B. ATP and enzymes
C. paired nucleotides
D. receptor enzymes
If the structure of DNA were likened to a ladder, what would make up the “supporting structure” (not the “rungs”) of the ladder?
A. amino acids and sugars
B. nucleotide bases, including thymine
C. nucleotide bases, including uracil
D. sugar-phosphate molecules
The diagram above shows a portion of a DNA molecule. The letters in the diagram represent the four bases: adenine (A), thymine (T), guanine (G), and cytosine (C). Which sequence of bases do the question marks represent?
A. C-A-C
B. G-C-A
C. G-A-C
D. T-C-A
Which do DNA and RNA have in common?
A. Both are double stranded.
B. Both contain ribose molecules.
C. Both contain phosphate groups.
D. Both contain uracil.
Proteins are chains of amino acids bonded together. Which is the correct sequence for making proteins?
A. Information in DNA is formed into protein directly.
B. Information in RNA uses thermal energy to make protein.
C. Information in RNA mutates into DNA and then is made into protein.
D. Information in DNA is transferred into RNA and then made into protein.
What is the complimentary mRNA sequence to the DNA sequence A-T-T-G-C-A?
A. T-A-A-C-G-T
B. U-A-A-C-G-T
C. U-A-A-C-G-U
D. T-A-A-G-C-U
Why is the presence of DNA important for the cellular metabolic activities?
A. DNA directs the production of enzymes.
B. DNA is a structural component of the cell membranes.
C. DNA directly increases the solubility of nutrients.
D. DNA is the major component of cytoplasm.
What did Francesco Redi’s experiments disprove?
A. law of superposition
B. Cambrian explosion of life
C. endosymbiont theory
D. theory of spontaneous generation
What provides an explanation for the presence of mitochondria and chloroplasts in presentday cells?
A. biogenesis
B. endosymbiosis
C. spontaneous generation
D. superposition
How is the illustration below interpreted by many scientists?
A. Mitochondria and chloroplasts are parasites in cells.
B. Prokaryotes might have entered host cells as prey or parasites.
C. Eukaryotic cells evolved before prokaryotes.
D. Mitochondria and chloroplasts look similar.
When Charles Darwin was developing his theory of evolution, he considered variations in a population important. However, he could not explain how the variations occurred. Which two processes could cause variations?
A. symbiosis and metamorphosis
B. commensalism and mutualism
C. crossing over and mutations
D. phagocytosis and pinocytosis
Why are the structures shown below considered to be homologous?
A. They belong to organisms that evolved from separate ancestors.
B. They are the result of geographic isolation.
C. They belong to organisms that probably evolved from a common ancestor.
D. They are the result of sympatric speciation.
Homologous structures might be the result of a change in allele frequencies over successive generations. Why have these structures probably continued?
A. They were beneficial in a particular environment.
B. They were predestined in a species.
C. They made a particular organism more attractive to a mate.
D. They were neutral, not harmful, mutations.
What unique characteristic would the beetles shown below develop through biological adaptation if, over a period of years, the bark on the trees shown became spotted?
A. The beetles would become spotted.
B. The beetles would become plain.
C. About half the beetles would become spotted and half would not.
D. There would be no change.
According to the theory of natural selection, why are some individuals more likely than others to survive and reproduce?
A. They pass on to their offspring new characteristics they acquired during their lifetimes.
B. They are better adapted to exist in their environment than others.
C. They do not pass on to their offspring new characteristics they have acquired during their lifetimes.
D. They tend to produce fewer offspring than do others in the same environment.
In order for evolution to occur, what must happen in a population?
A. genetic drift
B. geographic isolation
C. natural selection
D. reproductive isolation
What is operating when unrelated species living in different parts of the world, but with similar niches, evolve similar traits?
A. convergent evolution
B. genetic drift
C. divergent evolution
D. parallelism
Scientists can estimate more accurately at what point various groups of organisms diverged evolutionarily from one another by using which source of information?
A. fossil record
B. DNA evidence
C. migration patterns
D. genetic equilibrium
What type of natural selection favors average individuals in a population?
A. disruptive selections
B. bias
C. directional selection
D. stabilizing selection
Define gene.
A section of dna that codes for a trait
List the stages of meiosis.
Interphase, Prophase I, Metaphase I, Anaphase I, Telophase I, Prophase II, Metaphase II, Anaphase II, Telophase II, Cytokinesis
Compute the number of chromosomes that the gametes of a cat (2n = 38 chromosomes) will have. Show your work.
38/2 = 19
Compare and contrast anaphase I and anaphase II.
In anaphase I homologous chromosomes go to opposite sides of the cell, in Anaphase II half of each chromosome go to the sides of each cell
Devise a theory that explains why the most complex animals only reproduce sexually.
They reproduce sexually because it provides more variation within the population. Asexual reproduction is a very simple process where only simple organisms can reproduce that way.
Describe the structure of DNA proposed by Watson and Crick.
The structure was a double helix that twists as it goes
Apply Chargaff ’s rule to decide how many guanine bases a length of DNA will have if it has 26 cytosine bases. Explain.
It would 26 guanine bases since A=G
Recall what happens to the DNA double helix so that DNA polymerase can begin adding appropriate nucleotides.
Dna Helicase unwinds DNA, proteins bind to the DNA, DNA primers get added to the strand of DNA
Explain what Okazaki fragments are.
Okazaki fragments are sections of DNA that get created on the lagging strand
Describe how Okazaki fragments (or other sections of DNA) are joined.
DNA ligase comes in and binds the sections together
Differentiate between transcription and translation.
Transcription makes RNA and translation makes proteins
Describe what paleontologists can infer from fossils.
They can see what happened in the past, what life forms existed
Describe the endosymbiont theory.
The endosymbiont theory states that prokaryotic cells lived with and entered other cells and created eukaryotic cells
Examine how photosynthetic prokaryotic cells changed the atmosphere of early Earth.
They added enough oxygen to create the atmosphere we have today that contain sustain larger organisms
List the four basic principles of Darwin’s theory of natural selection.
Population has variations.
Some variations are favorable.
More offspring are produced than survive
Those that survive have favorable traits.
Summarize Darwin’s ideas about evolution in one or two sentences.
Darwin believed that the environment selected the traits, those organisms with the best traits survived and reproduced
Compare and contrast artificial and natural selection.
Artificial selection is when we select the traits we think are desirable and natural selection is when the environment selects the traits
Define adaptation as it relates to evolution.
Adaptation is any characteristic that helps an organism survive
Match the phase of mitosis with the event (some will be used more than once some not at all).
A. Prophase B. Metaphase C. Anaphase D. Telophase
A Nuclear membrane disappears
D Chromosomes start to unwind
A Chromatin condenses into chromosomes
A Spindle apparatus appears
C Chromosomes start to pull apart
B Chromosomes line up at the center
D Nuclear membrane reappears
In what stage of the cell cycle does the DNA Replicate?
Interphase
List 3 differences between mitosis and meiosis.
1. Number of Cells
– Mitosis creates 2 identical cells
– Meiosis creates 4 individual cells
2. Number of chromosomes
– Mitosis creates cells with 46 chromosomes (2n – diploid)
– Meiosis creates cells with 23 chromosomes (n – haploid)
3. Locations
– Mitosis – somatic (“normal”) cells
– Meiosis – gametes (sex) cells
Label the following as homozygous (HO) or heterozygous (HE).
AA HO Bb HE ff HO
For each of the genotypes below, write the phenotype.
Round seeds are dominant to wrinkled
RR ____Round______
rr ______Wrinkled______
Rr ______Round______
For each phenotype, write the genotype. (Remember to use the letter of the dominant trait).
Brown eyes are dominant to blue eyes.
______bb______Blue _____BB,Bb______Brown
Directions: For the next questions, use the Punnett square below.
B= Brown eyes and b=blue eyes
B / bB
bb
What is the genotype of parent 1? ______Bb______
What is the phenotype of parent 2? ______Brown eyes______
What is the phenotype of the offspring in box with an “X”? ______Brown eyes______
What is the genotype of the offspring in the box with an “X”? ______BB______
What is the genotypic ratio of the offspring of the above cross? ______1:2:1______
Short hair is dominant over long hair in cats. Two heterozygous parents, Hh, are crossed.
a. What is the chance of getting a long hair cat? 25%
b. What is the genotypic ratio of the kittens? 1:2:1
c. What is the chance of getting a short hair cat? 75%
In people, the alleles for hair texture are an incomplete dominance. Your hair can be curly, straight or wavy. Predict the children when a wavy haired mom (CS) and a straight-haired dad (SS) have children.
a. What is the predicted genotypic ratio for the children? 2:2
b. What is the predicted phenotypic ratio for the children? 2:2
In dogs, black hair color (B) is dominant over a yellow hair color (b). One parent is heterozygous for black hair, while the other has yellow hair.
a. What is the probability of having yellow-haired puppies? 50%
b. What is the probability that the next puppy will also have a yellow hair? 50%
c. What is the probability of having a puppy that has black hair? 50%
In chickens, when a white rooster (FF) is crossed with a black hen (NN), all the chicks are black and white speckled. What chicks will be made if the speckled chicks mate?
a. What are the genotypes you will get? White, speckled, and black
b. What is the chance of each genotype? 25% FF, 50% FN, and 25% NN
c. What is the chance of getting a white chicken? 25%
In pea plants, T=tall and t=short. Which phenotypic ratio results when a heterozygous plant and a recessive plant are crossed? Tall:Short = 2:2
If a man with normal vision and his wife who is a carrier for colorblindness are crossed, looking at just their male children, what percent will be colorblind?
25%
A color-blind son has a father and a mother, both with normal vision. What must be the mother’s genotype?
XRXr
In snapdragons, plant color is an incomplete dominant trait. The plants can be red (RR), white (WW) or pink (RW). A red flower and a pink flower were crossed. Answer the following questions.
a. What is the chance of producing a white flower? 0%
b. What is the chance of producing a red flower? 50%
c. what is the genotypic ratio? 2:2
d. What is the percent chance of each genotype?50%
Vocabulary - Match the definitions with the terms.
D genotypes made of the same alleles
C different forms of genes for a single trait
B gene that is always expressed
E gene expressed only in homozygous state
A genotypes made of two different alleles
A. alleles
B. dominant
C. heterozygous
D. homozygous
E. recessive
A man with Type O blood marries a woman with heterozygous Type A blood.
What are the possible genotypes of the offspring? IAIi, ii
What are the possible phenotypes of the offspring? Heterozygous type a and type O
What is the probability of each genotype? 50%
What is the probability of each phenotype? 50%
In humans colorblindness (b) is an example of a sex-linked recessive trait. In this problem, a male with colorblindness marries a female who is not colorblind but carries the (b) allele. What is the chance of having a colorblind child?
50%
A man that has an AB blood type has a child with a woman with type B blood. Can they have a type O child?
No.
A man is heterozygous for type B blood. He has a child with a woman who is homozygous for type A blood.
What are the possible genotypes of their children? IAIB, IAi