Cell Bio Module 6 Quiz

Which of the following is a target of the APC:

A. Cyclin B

B. Separase

C. Cdc28

D. Cdc25

A. Cyclin B

Towards the end of Anaphase and Telophase, the cell elongates by which of the following mechanisms?

A. The astral microtubules grow towards the plus end and cell periphery, and the dynein motors attached to the plasma membrane try to walk towards the minus end of the astral microtubules, resulting in the cell stretching

B. The astral microtubules grow towards the cell plus end and cell periphery, and the kinesin motors attached to the plasma membrane try to walk towards the minus end of the astral microtubules, resulting in the cell stretching

C. The astral microtubules grow towards the minus end and cell periphery, and the dynein motors attached to the plasma membrane try to walk towards the plus end of the astral microtubules, resulting in cell stretching

D. The polar microtubules grow towards the plus end and cell periphery, and the dynein motors attached to the plasma membrane try to walk towards the minus end of the polar microtubules, resulting in cell stretching

A. The astral microtubules grow towards the plus end and cell periphery, and the dynein motors attached to the plasma membrane try to walk towards the minus end of the astral microtubules, resulting in the cell stretching

Chk1 is activated by:

ATR

Which of the following properties of the +4 stem cell is correct:

A. It can differentiate into Paneth Cells

B. All of the answer choices are correct

C. It can differentiate into enterocytes

D. It can differentiate into Goblet cells

B. All of the answer choices are correct

Which of the following incorrectly matches a mitotic motor protein with its function:

A. Kinesin-13 enhances microtubule (+) end growth, promoting kinetochore attachment.

B. Kinesin-7 aids in chromosome bi-orientation.

C. Kinesin-5 pushes the two asters apart.

D. Kinesin-4 interacts with polar microtubules to pull the chromosomes toward the center of the spindle.

A. Kinesin-13 enhances microtubule (+) end growth, promoting kinetochore attachment.

Daughter cells that form as a result of asymmetric cell division may differ in:

A. Shape

B. All of the answers are correct

C. Protein composition

D. Size

B. All of the answers are correct

What of the following definitions is incorrect:

A. Progenitor cells are generally capable of giving rise to all cells of a single tissue type

B. Pluripotent cells are competent to form all embryonic tissues but not extra-embryonic tissues

C. Stem cells are totipotent cells that have the capacity to self-renew

D. Totipotent cells are competent to form every tissue of the organism

A. Progenitor cells are generally capable of giving rise to all cells of a single tissue type

The microtubules that extend towards the center plate of the cell but don’t capture chromosomes are called _______________; the ones that capture chromosomes are called ______________; and the microtubules that extend towards the periphery of the cell are called ________________.

Polar MT; Kinetochore MT; Astral MT

During G_1, prereplication complexes:

Bind to ORC (origin recognition complex)

Cyclin D/Cdk4 functions during which of the following phases of the cell cycle:

A. G₂

B. M

C. S

D. G₁

D. G₁

Fully differentiated mouse fibroblasts can be reprogrammed or induced to form pluripotent stem cells when transfected with retroviral vectors that express:

A. SOX2

B. C-MYC

C. KLF4

D. All of the answers are correct

D. All of the answers are correct

Which of the following occurs during anaphase A:

A. Kinetochores remain attached to shortening kinetochore microtubules.

B. Chromosomes move to the spindle equator.

C. The spindle poles move closer together.

D. The spindle elongates.

A. Kinetochores remain attached to shortening kinetochore microtubules.

The Paneth cells migrate____________________ in the ___________________upon differentiation from intestinal LGR5+ stem cells.

Downward, intestinal crypt

Mitotic cyclin levels in early Xenopus embryos are regulated by:

Degradation by APC

The use of cell-based models to understand or treat human disease processes is aided by stem cells in all the following ways EXCEPT:

Provides proof that ES cells are pluripotent and can divide to make a normal animal

Which of the following statements is NOT true:

A. Teratoma is a benign tumor

B. Teratocarcinoma cells can differentiate into different cell types

C. Embryonic carcinoma cells arise from the embryo during development

D. Teratocarcinoma is a malignant tumor

C. Embryonic carcinoma cells arise from the embryo during development

During which stage of the cell cycle is the chromosome content of a mammalian liver cell 1n/haploid:

A. S

B. None of the answers is correct.

C. G1

D. G2

B. None of the answers is correct.

Poleward movement of chromosomes during anaphase A requires:

Kinetochore motor proteins

Capture of microtubule (+) ends by chromosomes occurs during:

Prometaphase

Neurons are amitotic and do not divide (or very rarely divide); but still, we get brain cancers. Based on that information, which one of the following is NOT true:

A. Cancerous cells can metastasize (migrate) from a different cancerous tissue to the brain at a late stage of cancer, but it is not brain cancer.

B. Glial cells (supporting/accessory cells) of the nervous tissue can divide uncontrollably and may lead to cancer.

C. Mutations in neurons can turn on the cell cycle and make the neurons divide uncontrollably, leading to cancer

D. Precursor cells of neurons and supporting glial cells called neuroblastoma can divide uncontrollably, causing cancer.

E. All of the choices are true

C. Mutations in neurons can turn on the cell cycle and make the neurons divide uncontrollably, leading to cancer

You perform an experiment where you prevent Cdc20 from binding to APC in a cell line that usually completes the cell cycle in 60 minutes. Your experiment prevents Cdc20 from binding to APC for 120 minutes, and then you fix and stain the DNA, securin, separase, and cohesin. Which of the following would NOT be found in the observed cell:

A. The cell would contain condensed chromosomes aligned at the metaphase plate.

B. Securin would be bound to separase (appear to co-localize).

C. Cohesins will be localized around the sister chromatids.

D. The DNA will be decondensed because the cell is in interphase.

D. The DNA will be decondensed because the cell is in interphase.

Congregation of the chromosomes at the metaphase plate is achieved EXCEPT by which of the following processes and components:

A. Dual-head Kinesin 4 orients and aligns the arms of the chromosomes properly at the metaphase plate to aid in proper segregation of the sister chromatids during the next phase of anaphase

B. Bi-orientation of chromosomes, where each kinetochore of the sister chromatids is attached to kinetochore MTs from the same spindle pole

C. Dual-head kinesin 7 pushing kinetochores towards the rapidly growing (+) end of that specific kinetochore MTs

D. Dynein motor proteins pulling the kinetochores towards the (-) end of the kinetochore MTs and Kinesin 13 rapidly shrinking that dynein-specific (+) end of the kinetochore MTs

B. Bi-orientation of chromosomes, where each kinetochore of the sister chromatids is attached to kinetochore MTs from the same spindle pole

Exit from mitosis depends on the degradation of:

Cyclin B

Which of the following characterizations of the maximum cell potential is FALSE:

A. The cells of the trophectoderm are pluripotent

B. The cells of the morula are totipotent

C. The cells of the inner cell mass are pluripotent

D. The cells of an eight-cell embryo are totipotent

A. The cells of the trophectoderm are pluripotent

In the mouse embryo, pluripotent stem cells are found in the:

 Inner cell mass

All the following statements about the destruction of cyclins are true EXCEPT:

A. Ubiquitin targets Cdks

B. Destruction is preceded by polyubiquitination

C. Destruction is carried out by proteasomes

D. Ubiquitination occurs at specific sites on target molecules

A. Ubiquitin targets Cdks

Separation of spindle poles during spindle formation and anaphase B MOST likely depends on which of the following:

A. (+) end-directed microtubule motors at the kinetochore

B. (+) end-directed microtubule motors in the microtubule overlap zone

C. (–) end-directed microtubule motors in the microtubule overlap zone

D. (+) end-directed microtubule motors at the cell cortex

B. (+) end-directed microtubule motors in the microtubule overlap zone

John was very excited to present his data in the lab meeting as his embryonic stem cells were healthy and growing rapidly. When he presented his data in the lab meeting, his supervisor asked him if he x-ray irradiated the feeder fibroblast cells and if there was a control experiment with only the fibroblasts. John said yes, he irradiated the cells but did not do a control. The supervisor was not convinced by the data and asked him to repeat the experiment with a proper control. Why?

A. All of the answers are correct

B. The control experiments with only the feeder cells will ensure that the feeder cells are producing OCT3/4, SOX2, KLF4 , and C-myc transcription factors

C. The control experiments with only the feeder cells will ensure that the feeder cells are secreting the growth factors

D. The control experiment will ensure that all the feeder cells have damaged DNA, causing cell cycle arrest

D. The control experiment will ensure that all the feeder cells have damaged DNA, causing cell cycle arrest

Which of the following is NOT true of mitotic microtubules:

A. Polar microtubules are required for maintaining spindle structure.

B. Kinetochore microtubules are responsible for pushing the spindle poles apart in anaphase B.

C. Astral microtubules extend from the spindle poles to the cell cortex and orient the axis of cell division.

D. Kinetochore microtubules use a search-and-capture mechanism to link spindle poles to kinetochores.

B. Kinetochore microtubules are responsible for pushing the spindle poles apart in anaphase B.

Electroconvulsive therapy (ECT) is a reasonable option for intractable depression or schizophrenia, but a mechanism of action has not been established. One credible hypothesis is related to neural plasticity. Below is the neuronal gene expression assay for four genes after ECT, normalized with the Hamilton depression rating scale of 21 items version (HAM-D-21). Which of the following conclusion you may NOT conclude from the data:

A. Neural plasticity steadily increases with the number of ECT administrations

B. ECT may increase neural plasticity

C. ECT seems to increase the expression of Yamanaka’s four transcription factors

D. ECT may convert adult neurons into IPSCs, which may divide and differentiate into healthy adult neurons

A. Neural plasticity steadily increases with the number of ECT administrations

All of the following are true about Cdk-cyclins EXCEPT:

A. They are heterotrimeric with  𝛂,𝛃, and 𝛄 subunits, and phosphorylate other proteins

B. They regulate the eukaryotic cell cycle by arresting progression through checkpoints along with other proteins

C. All of the answers are correct

D. They were originally known as mitosis promoting factors (MPFs).

E. Cyclins are destroyed by proteasomes in cyclic fashion after each particular phase of cell cycle such as G1, S, G2 and Mitosis

A. They are heterotrimeric with  𝛂,𝛃, and 𝛄 subunits, and phosphorylate other proteins

In the mitotic spindle, astral microtubules function to:

A. Anchor the spindle poles to the plasma membrane

Which of the following inhibits cyclin A/Cdk2 activity:

A. INK4

B. Both INK4 and Rb

C. Rb

D. p21^CIP

D. p21^CIP

Which of the following statements regarding HSC (hematopoietic stem cell) differentiation is false:

A. HSC division and differentiation is controlled by cytokines

B. HSCs generate all types of white blood cells, but not erythrocytes

C. HSC differentiation initially gives rise to common myeloid and common lymphoid progenitor cells, which are multipotent

D. HSCs are located in the embryonic liver and in adult bone marrow

B. HSCs generate all types of white blood cells, but not erythrocytes

Which of the following is targeted by the SCF complex:

A. Cdh1

B. securin

C. Sic1

D. Cyclin B

C. Sic1

Kinetochores assemble at the:

Centromere

The FIRST differentiation event following fertilization occurs when the:

Trophoectoderm separates from the inner cell mass

Which of the following type/s of embryonic cell/s has/have the ability to grow into a complete mammal in the mother’s uterus from the zygote stage:

A. Either Pluripotent or Totipotent

B. Pluripotent

C. Unipotent

D. Totipotent

E. Multipotent

D. Totipotent

Dolly, the famous sheep, was cloned using:

Somatic cell nuclear transfer

Which of the following is/are in the cell lineage that gives rise to T cells:

A. Pluripotent hematopoietic stem cell

B. Myeloid stem cell and pluripotent hematopoietic stem cell

C. GM-CFC

D. Myeloid stem cell

A. Pluripotent hematopoietic stem cell

In mammalian development, which of the following is the CORRECT chronological order of events:

A. Group of answer choices

B. Zygote, four-cell, compacted morula, blastocyst

C. Compacted morula, blastocyst, zygote, four-cell

D. Blastocyst, zygote, four-cell, compacted morula

E. Four-cell, compacted morula, blastocyst, zygote

B. Zygote, four-cell, compacted morula, blastocyst