Chapter 14,15, 22 Lecture 13-16 Flashcards
Which of the following statements about natural selection is a misconception?
Select one:
a. Natural selection acts on heritable variations in a population
b. In natural selection, traits that are favored depend on current environmental conditions
c. Natural selection involves differential reproductive success
d. Natural selection occurs as a result of competition among individuals in a population
e. Natural selection occurs when individuals evolve
f. All of the above statements are true
E
Which of the following is a karyotype?
Select one:
a. A display of all of the cell types in an organism
b. Organized images of a cell’s chromosomes
c. The appearance of an organism
d. A display of a cell’s mitotic stages
e. A list of all of the organisms’ genes
B
When crossing an organism that is homozygous recessive for a single trait with a heterozygote, what is the chance of producing an offspring with a homozygous recessive phenotype?
Select one:
a. 0%
b. 25%
c. 50%
d. 75%
e. 100%
C
Which of the following statements about a monohybrid cross and dihybrid cross is true?
Select one:
a. A monohybrid cross results in a 9:3:3:1 ratio whereas a dihybrid cross gives a 3:1 ratio
b. A monohybrid cross results in a 3:1 ratio whereas a dihybrid cross gives a 9:3:3:1 ratio
c. A monohybrid cross is performed for one generation, whereas a dihybrid cross is performed for two generations
d. A monohybrid cross involves organisms that are heterozygous for two characters and a dihybrid cross involves only one
e. A dihybrid cross involves organisms that are heterozygous for two characters and a monohybrid cross involves only one
f. B and E
The correct answers are: A dihybrid cross involves organisms that are heterozygous for two characters and a monohybrid cross involves only one, B and E.
F
From his observations in the Galapagos islands, Darwin reasoned that:
Select one:
a. Organisms adapted to new environments, giving rise to new species
b. The shape of a bird’s beak does not affect its ability survive and reproduce
c. All island species should be similar to each other
d. The organisms in the Galapagos had been specially created to thrive in that environment
e. A and B
A
During a study session about evolution, one of your fellow students remarks: “The giraffe stretched its neck while reaching for higher leaves; its offspring inherited longer necks as a result.” Which statement most likely to be helpful in correcting this student’s misconception?
Select one:
a. Only favorable adaptations have survival value
b. Spontaneous mutations can result in the appearance of new traits
c. Characteristics acquired during an organism’s life are generally not passed on through genes
d. Disuse of an organ may lead to its eventual disappearance
e. If the giraffes did not need to compete with one another, longer necks would not have been passed on to the next generation
C
What was the most significant conclusion that Gregor Mendel drew from his experiments with pea plants?
Select one:
a. Traits are inherited in discrete units, and are not the result of “blending”
b. There is considerable genetic variation in garden peas
c. Genes are composed of DNA
d. Recessive alleles occur more frequently in the F1 generation than do dominant ones
e. An organism that is homozygous for many recessive traits is at a disadvantage
f. None of the above
A
According to Lamarck, some birds have larger beaks due to
Select one:
a. Random changes in beak structure
b. Adaptations to different environments and feeding habits
c. Differences inherited from their ancestors
d. Inheritance of acquired characteristics
D
If the bacterium Staphylococcus aureus experiences a cost for maintaining one or more antibiotic-resistance genes, then what should happen in environments from which antibiotics are missing?
Select one:
a. The bacteria should try to make the cost worthwhile by locating and migrating to microenvironments where traces of antibiotics are present
b. The bacteria should start making and secreting their own antibiotics
c. These bacteria should be outcompeted and replaced by bacteria that have lost these genes
d. These genes should continue to be maintained in case the antibiotics ever appear
e. None of the above
C
The fact that all seven pea plants studied by Mendel obeyed the principle of independent assortment most probably indicates which of the following?
Select one:
a. None of the traits obeyed the law of segregation
b. All of the genes controlling the traits were located on the same chromosome
c. The formation of gametes in pea plants occurs by mitosis only
d. All of the genes controlling the traits behaved as if they were on different chromosomes
e. The diploid number of chromosomes in the pea plant was 7
D
