Bio 310 Cell Biology Review Questions

Both budding yeast and the bacteria E. coli are unicellular life forms. Which of the following statements explains why budding yeast can undergo sexual reproduction while E. coli cannot? a. Unlike E. coli, budding yeast can alternate between a diploid state and a haploid state. b. Unlike E. coli, budding yeast cannot multiply by undergoing cell division. c. Unlike E. coli, haploid budding yeast cells can undergo meiosis to produce the gametes necessary for sexual reproduction. d. E. coli DNA is unable to undergo homologous recombination, making it incapable of producing gametes. e. The four meiotic spores produced by E. coli are of the same mating type, when yeast produce fours spores with opposite mating types.

A

In the presence of an ATP analog that can bind myosin normally but cannot be hydrolyzed,

A myosin performs the power stroke but cannot be released from an actin filament

Indicate if each of the following structures is based on actin filaments (A), microtubules (M), or intermediate filaments (I). Your answer would be a five-letter string composed of letters A, M, and I only; e.g. AAAMM. ( ) The cell cortex that underlies the plasma membrane in most eukaryotic cells ( ) The mitotic spindle ( ) The nuclear lamina ( ) Cilia ( ) Filopodia

AMIMA

Which of the following are recognized by pattern recognition receptors as pathogenassociated molecular patterns? A. Double-stranded viral RNAs B. Formylmethionine-containing proteins C. Unmethylated CpG motifs D. Bacterial flagella components E. All of the above

All the Above

Which of the following statements is FALSE? a. Asexual reproduction typically gives rise to offspring that are genetically identical. b. Mutations in somatic cells are passed on to individuals of the next generation. c. Sexual reproduction allows for a wide variety of gene combinations. d. Gametes are specialized sex cells. e. The gametes are haploid.

B

A single nondisjunction event during meiosis a. will block recombination. b. will occur only during meiosis II. c. cannot occur with sex chromosomes. d. will result in the production of two normal gametes if it occurs during meiosis II. e. results in tow diploid and two tetraploid gametes.

D

Imagine meiosis in a diploid organism that only has a single chromosome. Like most diploid organisms, it received one copy of this chromosome from each of its parents and the two homologs are genetically distinct. If only a single homologous recombination event occurs during meiosis, which of the following choices below correctly describes the four gametes formed? a. None of the gametes will contain chromosomes identical to the chromosomes found in the original diploid cell. b. All four of the gametes will have chromosomes identical to the chromosomes found in the original diploid cell. c. Three of the gametes will have chromosomes identical to the chromosomes found in the original diploid cell, while one of the gametes will have chromosomes that are different. d. Two of the gametes will have chromosomes identical to the chromosomes found in the original diploid cell, while two of the gametes will have chromosomes that are different. e. All four of the gametes will have chromosomes different chromosomes than the one found in the original diploid cell.

D

Organisms that reproduce sexually a. must be haploid, unlike organisms that reproduce asexually. b. can reproduce only with a partner that carries the same alleles. c. create zygotes that are genetically identical to each other. d. undergo a sexual reproductive cycle that involves an alternation of haploid cells with the generation of diploid cells. e. can reproduce only with a partner that carries only dominant alleles.

D

Which of the following reasons was essential for Mendel to disprove the theory of blended inheritance? a. The traits that Mendel examined all involved genes that did not display linkage. b. The traits that Mendel examined all involved the reproductive structures of the pea plant. c. Mendel pioneered techniques permitting the fusion of male and female gametes from the same plant to produce a zygote. d. The traits that Mendel examined involved an allele that was dominant and an allele that was recessive. e. The dominant traits that Mendel examined all were paternally inherited.

D

Which of the following statements about the cytoskeleton is FALSE: a. The cytoskeleton is made up of three types of protein filaments. b. The cytoskeleton controls the location of organelles in eukaryotic cells. c. Elements of the cytoskeleton control the intracellular vesicular traffic. d. The cytoskeleton of a cell can change in response to the environment. e. Covalent bonds between protein monomers hold together cytoskeletal filaments.

E

Indicate true (T) and false (F) statements below regarding the human microbiota. Your answer would be a four-letter string composed of letters T and F only, e.g. TFTT. ( ) The number of human cells in our body is greater than the number of bacterial, fungal, and protozoan cells of our normal flora. ( ) There are far more genes in our microbiome than in our own genome. ( ) Infectious diseases currently cause more human deaths than cardiovascular diseases and cancers combined. ( ) All of the microorganisms that constitute the normal flora are nonpathogens

FTFF

Indicate true (T) and false (F) statements below regarding bacterial, viral, and eukaryotic pathogens. Your answer would be a four-letter string composed of letters T and F only, e.g. TTTT. ( ) Compared to bacteria and viruses, eukaryotic parasites have simpler life cycles. ( ) Most important pathogenic fungi show dimorphism, growing as either yeast or mold. ( ) Protozoan parasites often require more than one host to complete their life cycle. ( ) Plasmodium falciparum can invade human liver and red blood cells, as well as cells lining the gut in female Anopheles mosquitoes.

FTTT

Indicate whether each of the following descriptions better applies to an adaptive (A) or innate (I) immune response. Your answer would be a four-letter string composed of letters A and I only, e.g. AAAA. ( ) It is found in invertebrate and vertebrate animals as well as in plants. ( ) It has a long-lasting memory. ( ) It is highly specific to the particular invading pathogen. ( ) It employs natural killer (NK) cells to induce apoptosis in infected host cells.

IAAI

Intermediate filaments help protect animal cells from mechanical stress because filaments

In each cell are indirectly connected to the filaments of a neighboring cell through the desmosome, creating a continuous mechanical link between cells

Which of the following cytoskeletal filaments are abundant in an animal cell nucleus

Intermediate Filaments

Which of the following is not phagocytic: A. Macrophage B. Monocyte C. Neutrophil D. Lymphocyte E. Dendritic cell

Lymphocyte

Indicate whether each of the following descriptions is shared (S) or not shared (N) between macrophages and neutrophils in destroying invading pathogens in vertebrates. Your answer would be a four-letter string composed of letters S and N only, e.g. SSSS. ( ) They use a respiratory burst and create toxic reactive oxygen species to kill engulfed pathogens. ( ) They are normally found in most tissues even before pathogen invasion. ( ) They are long-lived and normally survive long after activation. ( ) They secrete pro-inflammatory cytokines upon encountering invading pathogens.

SNNS

The major microtubule-organizing center in animal cells

The centrosome

Which of the following statements about the structure of microtubules is FALSE? a. α-Tubulin and β-tubulin are covalently bound to make the tubulin dimer that then assembles into protofilaments. b. The two ends of a protofilament are chemically distinct, with α-tubulin exposed at one end and β-tubulin exposed at the other end. c. Within a microtubule, all protofilaments are arranged in the same orientation, giving the microtubule structural polarity. d. Tubulin dimers carrying GTP bind to the plus ends of microtubules. e. Microtubules are built from protofilaments that come together to make a hollow structure.

a

Cell movement involves the coordination of many events in the cell. Which of the following phenomena is not required for cell motility? a. myosin-mediated contraction at the rear of the moving cell b. integrin association with the extracellular environment c. nucleation of new actin filaments d. release of Ca2+ from the sarcoplasmic reticulum e. actin polymerization at the leading edge of the cell

d