If intelligent extraterrestrials visited Earth 475 million years ago, and then again 300 million years ago (at the close of the Carboniferous period), what trends would they have noticed in Earth's terrestrial vegetation over this period?
1. a trend from dominant gametophytes to dominant sporophytes
2. a trend from sporangia borne on modified leaves (sporophylls) to sporangia borne on stalks (seta)
3. a trend from no true leaves, to microphylls, to megaphylls
4. a trend from soil-surface-hugging plants to "overtopping" plants
5. a trend toward increased lignification of conducting systems
A) 1 and 3
B) 3, 4, and 5
C) 1, 2, 4, and 5
D) 1, 3, 4, and 5
E) 2, 3, 4, and 5
The open ocean is the most extensive biome on earth.
The Sun is the nearest star to Earth.
Plnaet Earth
Comparison of Ceres with the Moon and Earth
The basalt below the hominins is dated to 1.8 million years ago, and the geomagnetic polarity of the
Cranial capacity has increased approximately fourfold over the last 3.5 million years of hominin evo