Ultrastructural studies have led to the characterization of two distinctive cytological

pathways of PCD in plants;

I) Vacuolar-type PCD

II) Hypersensitive response-type (HR-type) PCD

a) cytosol and all its organelles, including the plasma membrane, are completely brokendown

b) The vacuole loses water, resulting in marked cell shrinkage, contraction from the cell wall,

and nuclear DNA degradation

c) PCD occurs in leaves in response to microbial attack

d) cell wall is either partially or completely digested as well, as in endosperm tissue

e) Continued water loss from the cytosol leads to the breakdown of the plasma membrane

and the release of residual cellular contents into the apoplast

Given characterization of PCD pathway match with its type PCD?

#Question id: 8289

#Unit 9. Diversity of Life Forms

The term convergent evolution is most applicable to which of the following features?

#Question id: 8290

#Unit 9. Diversity of Life Forms

If, someday, an archaean cell is discovered whose rRNA sequence is more similar to that of humans than the sequence of mouse rRNA is to that of humans, the best explanation for this apparent discrepancy would be ________.

#Question id: 8291

#Unit 9. Diversity of Life Forms

Which of the following pairs are the best examples of homologous structures?

#Question id: 8292

#Unit 9. Diversity of Life Forms

Some molecular data place the giant panda in the bear family (Ursidae) but place the lesser panda in the raccoon family (Procyonidae). If the molecular data best reflect the evolutionary history of these two groups, then the morphological similarities of these two species is most likely due to ________.

#Question id: 8293

#Unit 9. Diversity of Life Forms

The importance of computers and of computer software to modern systematics s is most closely linked to advances in ________.

#Question id: 8294

#Unit 9. Diversity of Life Forms

The common ancestors of birds and mammals were very early (stem) reptiles, which almost certainly possessed three-chambered hearts (two atria, one ventricle). Birds and mammals, however, are alike in having four-chambered hearts (two atria, two ventricles). The fourchambered hearts of birds and mammals are best described as ________.