Pathways for phloem unloading and short distance transport. The sieve element–companion cell complex (SE–CC) is considered a single functional unit. The presence of plasmodesmata is assumed to provide functional_______Y_______.  An absence of plasmodesmata between cells indicates an______Z________.

#Question id: 8967

#Unit 9. Diversity of Life Forms

#Question id: 26948

#Unit 10. Ecological Principles

Calculate the population doubling time, if given the intrinsic rate of increase is 1.2?

#Question id: 23702

#Unit 13. Methods in Biology

#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: 26430

#Unit 3. Fundamental Processes

If the mismatch is near 5’ then which of the following will degrade strands of DNA in the 3’ → 5’ direction