Biology 156 Unit 11 Self-test
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- What organism did Mendel work with to determine patterns of inheritance?
- peas
- Why was Mendel so successful in his research?
-
all of the above
A. he was very meticulous in conducting experiments and recording data
B. he made a good choice of organism to study, since he could ensure self fertilization or cross-fertilization
C. he carefully chose characteristics that each occurred in two distinct forms - Varieties of plants in which self-fertilization produces offspring that are identical to the parents are referred to as:
- true-breeding
- The offspring of two different varieties are called:
- hybrids
- The parents in a genetic cross are called the:
- P generation
- The offspring in a cross of P individuals are called the:
- F1 generation
- The offspring in a cross of F1 individuals are called the:
- F2 generation
- A cross in which the parents differ in only one characteristic (or a cross in which we are looking at only one trait) is called:
- a monohybrid cross
- Which of the following hypotheses was developed by Mendel?
-
all of the above
A. There are alternative forms of genes, the units that determine heritable traits.
B. For each inherited characteristic, an organism has two genes, one from each parent.
C. A sperm or egg carries only one allele for each inherited trait.
D. When the two genes of a pair are different alleles, one allele is often fully expressed while the other is not expressed. - An alternative form of a gene is called:
- an allele
- The allele that is expressed, regardless of the other allele is the:
- dominant allele
- The allele that is expressed only if there is no dominant allele present is:
- the recessive allele
- If an organism has two identical alleles for a particular gene, that organism is:
- homozygous
- If an organism has different alleles for a particular gene, that organism is:
- heterozygous
- The observable physical traits of an organism is the:
- phenotype
- The actual genetic makeup of an organism is the:
- genotype
- Research since Mendel's time has established that the principle of the segregation of genes during gamete formation:
- applies to all sexually reproducing organisms
- Why can individuals with different genotypes have the same phenotype?
- individuals with a dominant phenotype could be either homozygous or heterozygous
- Alleles of a gene are found at ___ chromosomes
- the same locus on homologous
- A cross in which the parents differ in two characteristics (or a cross in which we are looking at two traits) is called:
- a dihybrid cross
- Mendel's principle of independent assortment states that each pair of ___ separate independently during ___.
- alleles, gamete formation
- A testcross is used to determine the genotype of an unknown individual by mating it with an individual who is ___.
- homozygous recessive
- Which of the following statements is true?
- recessive traits may be more common than dominant traits
- A family tree that shows information about genetic traits is a:
- pedigree
- If someone is a carrier of a recessive genetic disorder, it means they have ___ of the allele, and ___ exhibit symptoms of the disorder.
- one copy, do not
- A carrier of a genetic disorder who does not show symptoms is most likely to be ___ to transmit it to offspring.
- heterozygous for the trait and able
- Cystic fibrosis is
-
all of the above
A. the most common lethal genetic disease in the United States
B. due to a recessive allele
C. only present in a person who has two copies of the allele
D. characterized by an excessive secretion of very thick mucus from the lungs and other organs - Most genetic disorders of humans are caused by:
- recessive alleles
- Which of the following reasons accounts for the fact that dominant alleles that cause lethal disorders are less common than recessive alleles that cause lethal disorders?
- B. Most individuals carrying a lethal dominant allele have the disorder and die before they reproduce, whereas individuals carrying a lethal recessive allele are more likely to be healthy and reproduce.
- Aside from customs and laws, why is it GENETICALLY a bad idea to mate with close relatives and produce offspring?
- close relatives are more likely to carry the same harmful recessive alleles and produce offspring homozygous for a harmful recessive trait
- What is the name of this method of fetal testing: A small amount of amniotic fluid is removed using a needle through the mother's abdomen. The fluid is tested for genetic disorders using biochemical tests. Also, the cells can be cultured for several week
- amniocentesis
- What is the name of this method of fetal testing: High-frequency sound waves are used to produce images of the fetus on a monitor.
- ultrasound imaging
- What is the name of this method of fetal testing: A tube, inserted through the mother's vagina and cervix, is used to suction off small amounts of fetal tissue from the placenta. The collected cells are used to produce a karyotype, and to perform a few b
- chorionic villus sampling
- Which of the following methods of fetal testing is virtually risk free?
- ultrasound imaging
- When hybrids have an appearance in between the phenotypes of the two parental varieties, it is called
- incomplete dominance
- When two alleles different, but both are expressed in a heterozygous individual, it is called:
- codominance
- Imagine that beak color in a finch species is controlled by a single gene. You mate a finch homozygous for a yellow colored beak with a finch homozygous for a red colored beak, and get many offspring. All of the offspring have orange colored beaks. This
- incomplete dominance
- The impact of a single gene on more than one trait is called:
- pleiotropy
- Sickle-cell disease is an example of pleiotropy because it leads to:
-
all of the above
A. damaged organs
B. pain
C. fever
D. anemia - Which of the following individuals is more likely to survive the effects of malaria infection?
- heterozygote individual with one normal and one sickle-cell allele
- Genetic testing that determines whether a person carries a potentially harmful recessive allele, which could be passed on to offspring is best called:
- carrier testing
- Diagnostic testing that checks for genetic disorders in unborn babies is called:
- prenatal testing
- Genetic testing that helps determine a person's risk for developing a specific disorder in the future is best called:
- predictive testing
- When two or more genes affect a single phenotypic characteristic, it is called:
- polygenic inheritance
- Dr. Smith's parents have normal hearing. However, Dr. Smith has an inherited form of deafness. This form of deafness is a recessive trait that is associated with the abnormal allele "d". The normal allele at this locus, associated with normal h
- Dd and Dd
- The gene for fin color in fish has two alleles: gold (G) which is dominant, and silver (g) which is recessive. What will be the genotype ratio of a cross between a "GG" parent and a "gg" parent?
- 100% Gg
- The gene for eye color in beetles has two alleles: red (R) which is dominant, and yellow (r) which is recessive. What will be the phenotype ratio of a cross between two "Rr" parents?
- 3 red eyes : 1 yellow eyes
- The gene for eye color in beetles has two alleles: red (R) which is dominant, and yellow (r) which is recessive. The gene for leg length in beetles has two alleles: long (B) which is dominant, and short (b) which is recessive. What is the phenotype ratio
- 100% red eyes, short legs
- Which of the following genetic crosses would be predicted to give a phenotypic ratio of 9:3:3:1?
- SsYy x SsYy
- To identify the genotype of a dominant plant as either homozygous dominant (HH) or heterozygous (Hh), you could do a test cross with plants of genotype:
- hh
- Given a cross of AaBb x aaBb, what is the probability of an offspring having the genotype aabb?
- 1/8
- Given a cross of AaBBCc x AaBbCC, what is the probability of an offspring having the genotype AABBCC?
- 1/16
- In snapdragons, flower color is inherited through incomplete dominance. A RR plant has red flowers, a WW plant has white flowers, and a RW plant has pink flowers. What is the genotype ratio of crossing a red flower with a pink flower?
- 1 RR : 1 RW
- In bearflowers, plant height is inherited through incomplete dominance. A TT plant is tall, a SS plant is short, and a TS plant is medium height. What is the phenotype ratio of crossing a tall plant and a short plant?
- 100% medium height
- Sickle-cell disease is inherited as a codominant trait. If a person with normal hemoglobin and a person who is heterozygous (sickle-cell trait) mate and have a child, what are the chances that the child will be homozygous for sickle-cell disease?
- 0%
- A woman with type A blood and a man with type O blood could potentially have offspring with which of the following blood types?
- type A or type O
- A woman with type A blood and a man with type B blood could potentially have offspring with which of the following blood types?
- type A, type B, type AB, or type O
- Suppose hair color is inherited as a polygenic trait involving four genes, and is determined by the additive effects of dominant alleles. Which of the following genotypes would have the same hair color as AaBBCcdd?
- aabbCCDD
- In pea plants, spherical seeds (S) are dominant to dented seeds (s). In a genetic cross of two plants that are heterozygous for the seed shape trait, what fraction of the offspring should have spherical seeds?
- 1/4
- A phenotypic ratio of 3:1 in the offspring of a mating of two organisms heterozygous for a single trait is expected when:
- the alleles segregate during meiosis.
- In Mendel's "Experiment 1," true breeding pea plants with spherical seeds were crossed with true breeding plants with dented seeds. (Spherical seeds are the dominant characteristic). Mendel collected the seeds from this cross, grew F1-generatio
- All the F1 and 3/4 of the F2 generation seeds were spherical.
- A genetic cross between two F1-hybrid pea plants for spherical seeds will yield what percent spherical-seeded plants in the F2 generation? (spherical is dominant over dented)
- 75%
- A genetic cross between two F1-hybrid pea plants having yellow seeds will yield what percent green-seeded plants in the F2 generation? Yellow seeds are dominant to green.
- 25%
- When true-breeding tall stem pea plants are crossed with true-breeding short stem pea plants, all of the _________ plants, and 3/4 of the __________ plants had tall stems. Therefore, tall stems are dominant
- F1, F2
- To identify the genotype of yellow-seeded pea plants as either homozygous dominant (YY) or heterozygous (Yy), you could do a test cross with plants of genotype _______.
- yy
- A test cross is used to determine if the genotype of a plant with the dominant phenotype is homozygous or heterozygous. If the unknown is homozygous, all of the offspring of the test cross have the __________ phenotype. If the unknown is heterozygous, ha
- dominant, recessive
- In Mendel's experiments, if the gene for tall (T) plants was incompletely dominant over the gene for short (t) plants, what would be the result of crossing two Tt plants?
- 1/4 would be tall; 1/2 intermediate height; 1/4 short
- A genetic cross of inbred snapdragons with red flowers with inbred snapdragons with white flowers resulted in F1-hybrid offspring that all had pink flowers. When the F1 plants were self-pollinated, the resulting F2-generation plants had a phenotypic rati
- heterozygous plants have a different phenotype than either inbred parent because of incomplete dominance of the dominant allele.
-
Human blood type is determined by co-dominant alleles. There are three different alleles, known as IA, IB, and i. The IA and IB alleles are co-dominant, and the i allele is recessive.
The possible human phenotypes for blood group are type A, -
all of the above
A. type A
B. type B
C. type AB
D. type O - Manx cats are heterozygous for a dominant mutation that results in no tails (or very short tails), large hind legs, and a distinctive gait. The mating of two Manx cats yields two Manx kittens for each normal, long-tailed kitten, rather than three-to-one
- lethal
- What are the possible blood types of the offspring of a cross between individuals that are type AB and type O? (Hint: blood type O is recessive)
- A or B
- Could you please help me? I have a question that is NOT a homework question. I am a Junior in High School. "Could a man with type B blood and a woman with type AB produce a child with type O blood?" I think not, because type O is recessive, and
- . Not possible
- What if the mother is type O+ and the father is A-? What would the offspring's blood type be? --Mark
- A+, A-, O+, or O-
- If the mother of a child is blood type O+ and the child is A-, what blood type would the father be? Does the Rh factor of the child being - mean that one of the parents has to be negative? Both of my parents are Rh - all of us siblings are Rh- as well. C
- A+, A -, AB+, or AB-
- I have been reading your info about inheritance of blood types and I am getting very confused! I am trying to figure out what blood type the father of my son could have since my son and I are both type A+. Also, my brother is type 0 and my mom is A+. We
- A, AB, B, or O
- Thanks so much for your prompt reply. Here is the scenario....paternity isn't going to be established...it is going to lay...for lack of a better expression. My daughter is type A, my grandson is type B+, we do not know the types of the two gentlemen in
- AB or B
- We were surfing the net for information on how to confirm blood types inherited from our parents. Your home page offered a lot of good, basic information, but since we are non-bio-science types, our understanding is dated back to high school. Could you o
- Unlikely
- A pea plant is heterozygous for both seed shape and seed color. S is the allele for the dominant, spherical shape characteristic; s is the allele for the recessive, dented shape characteristic. Y is the allele for the dominant, yellow color characteristi
-
25% of gametes are SY; 25% of gametes are Sy;
25% of gametes are sY; 25% of gametes are sy. - A phenotype ratio of 9:3:3:1 in the offspring of a mating of two organisms heterozygous for two traits is expected when:
- the gene pairs assort independently during meiosis
- The gametes of a plant of genotype SsYy should have the genotypes:
- SY, Sy, sY, and sy
- Which of the following genotypes would you not expect to find among the offspring of a SsYy x ssyy test cross:
- SsYY
- The expected phenotypic ratio of the progeny of a SsYy x ssyy test cross is:
- 1:1:1:1
- In a dihybrid cross, AaBb x AaBb, what fraction of the offspring will be homozygous for both recessive traits?
- 1/16
- Following a SsYy x SsYy cross, what fraction of the offspring are predicted to have a genotype that is heterozygous for both characteristics?
- 4/16
- In a dihybrid cross, SsYy x SsYy, what fraction of the offspring will be homozygous for both traits?
- 1/4
- If Mendel's crosses between tall, spherical-seeded plants and short, dented-seeded plants had produced many more than 1/16 short, dented-seeded plants in the F2 generation, he might have concluded that:
- the spherical seed and tall traits are linked
- In Mendel's experiments, the spherical seed character (SS) is completely dominant over the dented seed character (ss). If the characters for height were incompletely dominant, such that TT are tall, Tt are intermediate and tt are short, what would be the
- All the progeny would be spherical-seeded and intermediate height.
- Two unlinked loci effect mouse hair color. CC or Cc mice are agouti. Mice with genotype cc are albino because all pigment production and deposition of pigment in hair is blocked. At the second locus, the B allele (black agouti coat) is dominant to the b
- BbCc
- Two unlinked loci effect mouse hair color. AA or Aa mice are agouti. Mice with genotype aa are albino because all pigment production is blocked, regardless of the phenotype at the second locus. At the second locus, the B allele (agouti coat) is dominant
- 9 agouti: 3 black: 4 albino