Question

the evolution and spread of grasses on earth has been associated with what?
global cooling
global warming
the permian extinction
the kt event
26 multiple choice 10 points
a single layer of epithelial cells which are flattened in shape would be categorized as which of the following types of epithelial tissues?
simple cuboidal
stratified squamous
simple squamous
stratified cuboidal
27 multiple choice 10 points
what was the greatest mass extinction that he earth has ever known?

Explanation:

Question 1 (Grasses evolution):

Grasses evolved and spread during periods of global cooling (e.g., Cenozoic cooling trends), adapting to drier, cooler environments. Global warming is opposite; Permian extinction (Permian - Triassic) and KT event (Cretaceous - Tertiary, dinosaur extinction) are unrelated to grass evolution.

• Simple Cuboidal: Single layer, cube - shaped (not flattened).
• Stratified Squamous: Multiple layers, flattened (but "stratified" means multiple layers, not single).
• Simple Squamous: Single layer, flattened cells (matches "single layer" and "flattened").
• Stratified Cuboidal: Multiple layers, cube - shaped.

The Permian - Triassic extinction (Permian extinction) was the greatest, with ~90 - 96% of species going extinct. KT event (dinosaur extinction) is smaller; Ordovician and Devonian extinctions are less severe than Permian.

Answer:

A. Global cooling

Question 2 (Epithelial tissue):