#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: 6943
#Unit 5. Developmental Biology
The portion of the blastoderm-stage embryo which will give rise to most ectodermal, mesodermal, and endodermal tissues is called the:
#Question id: 5529
#Unit 5. Developmental Biology
In humans, organogenesis in the embryo is basically accomplished by the end of which period of the pregnancy?
#Question id: 9229
#Unit 9. Diversity of Life Forms
Which of the following is a generally accurate statement about the current research regarding forest fragmentation?
#Question id: 4948
#Unit 11. Evolution and Behavior
RNA molecules can both carry genetic information and be catalytic. This supports the proposal that