#Question id: 7764
#Unit 5. Developmental Biology
Cellular senescence
may have evolved to protect organisms against cancer. Instead of dividing out
of control, the cells die. Cellular senescence appears to be regulated by
several tumor suppressor genes, especially p53.what is the most appropriate
reason behind this,
1) Transcription
factor p53 is thought to suppress tumorigenesis by causing cell arrest and
senescence in response to short telomeres, DNA damage, and viral or external
signals to divide
2) This factor can
stop the cell cycle, cause cellular senescence in rapidly dividing cells,
instruct genes to initiate cellular apoptosis, and activate DNA repair enzymes.
3) Induction of apoptosis or cellular senescence by p53 always beneficial.
#Question id: 23558
#General Aptitude
#Question id: 3531
#Unit 8. Inheritance Biology
Due to independent assortment resulting gamete is
#Question id: 7755
#Unit 5. Developmental Biology
#Question id: 2990
#Unit 2. Cellular Organization
Mitotic CDK complexes are maintained in an inactive state through inhibitory phosphorylation of the CDK subunit. Two highly conserved tyrosine and threonine residues in mammalian CDKs are subject to regulated phosphorylation.
Gene |
Mutant phenotypes |
A. Wee1 |
i. the cell does not divide but continues to grow |
B. CAK kinase |
ii. mitotic cyclins are inactivated |
C. cdc25 phosphatase |
iii. premature entry into mitosis |
The following table enlists genes and phenotypes observed on mutation of these genes but not correctly matched. Which one of the following combinations is correctly matched ?