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This section includes 7 Mcqs, each offering curated multiple-choice questions to sharpen your Biochemistry knowledge and support exam preparation. Choose a topic below to get started.
1. |
Passage of a cell through stages of cell cycle is controlled by a protein kinase that phosphorylates many different proteins at appropriate times. |
A. | Cdk activating kinase |
B. | Cyclin-dependent kinase |
C. | Cyclins |
D. | Tyrosine kinase |
Answer» C. Cyclins | |
2. |
Which of the following occurs in meiosis but not in mitosis? |
A. | Attachment of spindle fibers to kinetochore |
B. | Replication of DNA prior to start of cell division |
C. | Separation of sister chromatids at anaphase |
D. | Pairing of homologous chromosomes at metaphase plate |
Answer» E. | |
3. |
At which cell cycle checkpoint, cell cycle is halted if cell s DNA is damaged? |
A. | G<sub>1</sub> S |
B. | S G<sub>2</sub> |
C. | G<sub>2</sub> M |
D. | G<sub>0</sub> G<sub>1</sub> |
Answer» B. S G<sub>2</sub> | |
4. |
At the end of each phase of cell cycle cyclins activating Cdks in that phase are inactivated irreversibly by _____________ |
A. | Multiple phosphorylations |
B. | De-phosphorylation |
C. | Ubiquitinylation |
D. | Destabilizing by proteolysis in a proteosome |
Answer» E. | |
5. |
Cyclin dependent kinases which control progression through cell cycle checkpoints are totally activated by which of the following? |
A. | Binding to cyclin, plus phosphorylation by a Cdk activating protein kinase |
B. | Binding to cyclins |
C. | Phosphorylation by Cdk activating protein kinase |
D. | Phosphorylation by a tyrosine kinase |
Answer» B. Binding to cyclins | |
6. |
Cdk2/cyclinE functions in ____________ |
A. | G<sub>2</sub>/M transition |
B. | G<sub>2</sub> |
C. | M |
D. | G<sub>1</sub>/S transition |
Answer» E. | |
7. |
What is Ubiquitin? |
A. | Protein kinase |
B. | Protease |
C. | Component of the electron transport system |
D. | Protein that tags another protein for proteolysis |
Answer» E. | |