Biology 1107 (CH 11-14, 22)

Quaking aspen can send out underground stems for asexual reproduction. Sexual reproduction is not common, but when it does happen, the haploid gametes have 19 chromosomes. How many chromosomes are in the cells of the underground stems? a) 9 b) 10 c) 19 d) 38

D

Scientists isolate cells in various phases of the cell cycle. They find a group of cells that have 1 ½ times more DNA than G1 phase cells. The cells of this group are _______. a) Between the G1 and S phases in the cell cycle b) In the G2 phase of the cell cycle c) In the M phase of the cell cycle d) In the S phase of the cell cycle

D

The mitotic spindle is a microtubular structure that is involved in _______. a) Splitting of the cell (cytokinesis) following mitosis b) Triggering the compaction and condensation of chromosomes c) Dissolving the nuclear membrane d) Separation of sister chromatids

D

Which of the following defines a genome? a) The complete set of an organism's polypeptides b) The complete set of a species' polypeptides c) A karyotype d) The complete set of an organism's genes and other DNA sequences

D

Which of the following statements about independent assortment and segregation is correct? a) The law of independent assortment requires describing two or more genes relative to one another b) The law of segregation requires describing two or more genes relative to one another c) The law of independent assortment is accounted for by observation of prophase I d) The law of segregation is accounted for by anaphase of mitosis

A

Which of these conditions are always true of populations evolving due to natural selection? Condition 1: The population must vary in traits that are heritable. Condition 2: Some heritable traits must increase reproductive success. Condition 3: Individuals pass on most traits that they acquire during their lifetime. a) Condition 1 only b) Condition 2 only c) Condition 1 and 2 d) Conditions 2 and 3

A

A G-protein receptor with GTP bound to it ______. a) Is in its active state b) Signals a protein to maintain its shape and conformation c) Will use cGMP as a second messenger d) Directly affects gene expression

A

A population of organisms will not evolve if ______. a) All individual variation is due only to environmental factors b) The environment is changing at a relatively slow rate c) The population size is large d) The population lives in a habitat without competing species present.

A

During a study session about evolution, one of you fellow students remarks, "The giraffe stretched its neck while reaching for higher leaves; its offspring inherited longer necks as a result." Which statement is most likely to be helpful in correcting this student's misconception? a) Characteristics acquired during an organism's life are generally not passed on through genes b) Spontaneous mutations can result in the appearance of new traits c) Only favorable adaptations have survival value d) Disuse of an organ may lead to its eventual disappearance

A

If a cell has completed meiosis I and is just beginning meiosis II, which of the following is an appropriate description of its contents? a) It has half the amount of DNA as the cell that began meiosis b) It has half the chromosomes but twice the DNA of the originating cell c) It has one-fourth the DNA and one-half the chromosomes as the originating cell d) It is identical in content to another cell formed from the same meiosis I event

A

In general, a signal transmitted via phosphorylation of a series of proteins ______. a )Results in a conformational change to each protein b) Requires binding of a hormone to an intracellular receptor c) Activates a transcription event d) Generates ATP in the process of signal transduction

A

Metaphase is characterized by ______. a) Aligning of chromosomes on the equator b) Splitting of centromeres c) Cytokinesis d) Separation of sister chromatids

A

The cow Bos primigenius (which is bred for meat and milk) has a smaller brain and larger eyes than closely related wild species of ungulates. These traits most likely arose by _____. a) Natural selection, because these traits evolved in the population over time b) Natural selection, because these traits were not consciously selected by humans c) Artificial selection, because changed in these traits co-occurred with human selection for high milk output and high muscle content d) Artificial selection, because these animals differ from their close relatives and common ancestor

A

The first gap in the cell cycle (G1) corresponds to __________. a) Normal growth and cell function b) The phase in which DNA is being replicated c) The beginning of mitosis d) The phase between DNA replication and the M phase

A

The toxin of Vibrio cholerae causes profuse diarrhea because it _______. a) Modifies a G protein involved in regulating salt and water secretion b) Binds with adenylyl cyclase and triggers the formation of cAMP c) Signals IP3 to act as a second messenger for the release of calcium d) Modifies calmodulin and activates a cascade of protein kinases

A

What is the final result of mitosis in a human? a) Genetically identical 2n somatic cells b) Genetically different 2n somatic cells c) Genetically identical 1n somatic cells d) Genetically identical 2n gamete cells

A

Caffeine is an inhibitor of phosphodiesterase. Therefore, the cells of a person who has recently consumed coffee would have increased levels of ______. a) Phosphorylates proteins b) cAMP c) Adenylyl cyclase d) Activated G proteins

B

Catastrophism was Cuvier's attempt to explain the existence of _____. a) Evolution b) The fossil record c) Uniformitarianism d) The origin of new specie

B

Crossing over normally takes place during which of the following processes? a) Meiosis II b) Meiosis I c) Mitosis d) Mitosis and Meiosis II

B

How is plant cell cytokinesis different from animal cell cytokinesis? a) The contractile filaments found in plant cells are structures composed of carbohydrates; the cleavage furrow in animal cells is composed of contractile phospholipids. b) Plant cells deposit vesicles containing cell-wall building blocks on the metaphase plate; animal cells form a cleavage furrow. c) The structural proteins of plant cells separate the two cells; in animal cells, a cell membrane separates the two daughter cells. d) Plant cells divide after metaphase but before anaphase; animal cells divide after

B

If there are 20 duplicated chromosomes in a cell, how many centromeres are there? a) 10 b) 20 c) 30 d) 40

B

Kinetochore microtubules assist in the process of splitting centromeres by ______. a) Using motor proteins to split the centromere at specific arginine residues b) Creating tension by pulling toward opposite poles c) Sliding past each other like actin filaments d) Phosphorylating the centromere, thereby changing its conformation

B

Mendel continued some of his experiments into the F2 or F3 generation to ________. a) Obtain a larger number of offspring on which to base statistics b) Observe whether or not a recessive trait would reappear c) Observe whether or not the dominant trait would reappear d) Distinguish which alleles were segregating

B

What do we mean when we use the terms monohybrid cross and dihybrid cross? a) A monohybrid cross involves a single parents, whereas a dihybrid cross involves two parents b) A dihybrid cross involves organisms that are heterozygous for two characters that are being studied, and a monohybrid cross involves organisms that are heterozygous for only one character being studied c) A monohybrid cross is performed for one generation. Whereas a dihybrid cross is performed for two generations d) A monohybrid cross results in a 9:3:3:1 ratio whereas a dihybrid cross gives a 3:1 ratio.

B

Albinism is an autosomal (not sex-linked) recessive trait. A man and woman are both of normal pigmentation, but both have one parents who is albino (without melanin pigmentation). What is the probability that their first child will be albino? a) 0 b) ½ c) ¼ d) 1

C

An inhibitor of which of the following could be used to block the release of calcium from the endoplasmic reticulum? a) serine/threonine kinases b) Phosphodiesterase c) Phospholipase C d) Adenylyl cyclase

C

Darwin and Wallace's theory of evolution by natural selection was revolutionary because it _________. a) Was the first theory to refute the ideas of special creation b) Proved that individuals acclimated to their environment over time c) Dismissed the idea that species are constant and emphasized the importance of variation and change in populations d) Was the first time a biologist had proposed that species change through time

C

In eukaryotic cells, chromosomes are composed of ________. a) DNA and RNA b) DNA only c) DNA and proteins d) DNA and phospholipids

C

In yeast signal transduction, a yeast cell releases a mating factor which ______. a) Acts back on the same cell that secreted the mating factor, changing its development b) Passes through the membrane of neighboring cells, binds to DNA, and initiates transcription c) Binds to receptors on the membranes of other types of yeast cells d) Diffuses through the membranes of other cells, causing them to produce factors that initiate long distance migration

C

Mendel accounted for the observation that traits that had disappeared in the F1 generation reappeared in the F2 generation by proposing that _______. a) New mutations were frequently generated in the F2 progeny, "reinventing" traits that had been lost in the F1 b) The mechanism controlling the appearance of traits was different between the F1 and F2 plants c) Traits can be dominant or recessive, and the recessive traits were obscured by the dominant ones in the F1 d) Members of the F1 generation had only one allele for each trait, but members of the F2 had two alleles for each trait

C

Mendel crossed yellow-seeded and green-seeded pea plants and then allowed the offspring to self-pollinate to produce an F2 generation. The results were as follows: 6022 yellow and 2001 green (8023 total). The allele for green seeds has what relationship to the allele for yellow seeds? a) Dominant b) Incomplete dominant c) Recessive d) Codominant

C

Movement of the chromosomes during anaphase would be most affected by a drug that prevents _______. a) Nuclear envelope breakdown b) Elongation of microtubules c) Shortening of microtubules d) Formation of a cleavage furrow

C

Parasitic species tend to have simple morphologies. Which of the following statements best explains this observation? a) Parasites are lower organisms, and this is why they have simple morphologies b) Parties do not line long enough to inherit acquired characteristics c) Simple morphologies convey some advantage in most parasites d) Parasites have not yet had time to progress, because they are young evolutionarily.

C

Protein kinase is an enzyme that _______. a) Functions as a second messenger molecules b) Serves as a receptor for various signal molecules c) Activates or inactivated other proteins by adding a phosphate group to them d) Produces second messenger molecules

C

The bulldog ant has a diploid number of two chromosomes. Therefore, following meiosis, each daughter cell will have a single chromosome. Diversity in this species may be generated by mutations and ______. a) Crossing over b) Independent assortment c) Crossing over and independent assortment d) Nothing else

C

The somatic cells of a privet shrub each contain 46 chromosomes. How do privet chromosomes differ from the chromosomes of humans, who also have 46? a) Privet cells cannot reproduce sexually b) Privet sex cells have chromosomes that can synapse with human chromosomes in the laboratory c) Genes of privet chromosomes are significantly different than those in humans d) Privet shrubs must be metabolically more like animals than like other shrubs

C

Which of the following describes the ability of a single allele to have multiple phenotypic effects? a) Incomplete dominance b) Multiple alleles c) Pleiotropy d) Epistasis

C

Which of the following is a correct association? a) Kinase activity and the addition of a tyrosine b) Phosphodiesterase activity and the removal of phosphate groups c) GTPase activity and hydrolysis of GTP to GDP d) Adenylyl cyclase activity and the conversion of cAMP to AMP

C

Which of the following is a type of local signaling in which a cell secretes a signal molecule that affects neighboring cells? a) Hormonal signaling b) Autocrine signaling c) Paracrine signaling d) Synaptic signaling

C

Which of the following is the best explanation for the inability of a specific animal cell to reduce the Ca2+ concentration in its cytosol compared with the extracellular fluid? a) Blockage of the synaptic signal b) Loss of transcription factors c) Insufficient ATP levels in the cytosol d) Low levels of protein kinase in the cell

C

Which of the following is true of a species that has a chromosome number of 2n=16? a) The species is diploid with 32 chromosomes per cell b) The species has 16 sets of chromosomes per cell c) Each diploid cell has eight homologous pairs d) A gamete from this species has four chromosomes

C

A given organism has 46 chromosomes in its karyotype. Therefore, we can conclude that it must _______. a) Be human b) Be an animal c) Reproduce sexually d) Have gametes with 23 chromosomes

D

A sexually reproducing animal has two unlinked genes, one for head shape (H) and one for tail length (T). Its genotype is HhTt. Which of the following genotypes is possible in a gamete from this organism? a) Hh b) HhTt c) T d) HT

D

Mendel's observation of the segregation of alleles in gamete formation has its basis in which of the following phases of cell division? a) Prophase I of meiosis b) Anaphase II of meiosis c) Metaphase II of meiosis d) Anaphase I of meiosis

D

Which of the following statements is true of signal molecules? a) When signal molecules first bind to receptor tyrosine kinases, the receptors phosphorylate a number of nearby molecules. b) In response to some G protein-mediated signals, a special type of lipid molecules associated with the plasma membrane is cleaved to form IP3 and calcium. c) In most cases, signal molecules interact with the cell at the plasma membrane, enter the cell, and eventually enter the nucleus. d) Protein kinase A activation is one possible result of signal molecules binding to G protein-coupled receptors.

D

With what other idea of his time was Cuvier's theory of catastrophe most in conflict? a) The scala naturae b) The fixity of species c) Island biogeography d) Uniformitarianism

D