Answer:
Question 1
D
Question 2
C
Question 3
D
Explanation:
1. An ecosystem is MOST likely to return to its original condition after Tall prairie grass burns after being struck by lightning.
Here is a research paper in which they explained how this happened. (Komarek, E. V. (1971). Lightning and fire ecology in Africa. In Tall Timbers Fire Ecology Conference (Vol. 11, pp. 473-509).)
2. In some national parks, controlled fires are maintained by firefighters. The major reasons for using controlled burns to maintain certain ecosystems is to give nonnative plants a chance to colonize the region.
A recent article provided the insight of this situation (Xanthopoulos, G., Delogu, G. M., Leone, V., Correia, F. J., & Magalhães, C. G. (2020). Firefighting approaches and extreme wildfires. In Extreme Wildfire Events and Disasters (pp. 117-132). Elsevier.)
3. One reason for the change in the Galápagos ecosystem has been the introduction of species that were not on the island before, such as donkeys, goats, cats, dogs, and insects. The introduction of nonnative species MOST likely disrupt the balance of life on the islands due to greater competition for limited food sources.
Scientist said that food competition is actually a struggle to survive in any ecosystem here is the reference paper (Eckhardt, R. C. (1972). Introduced plants and animals in the Galapagos Islands. Bioscience, 22(10), 585-590.)
Fossils up to 75,000 years old can be dated with Carbon-14.
Radio isotopes can be used for the age determination of the fossils. Carbon-14 is a common isotope which is used for that purpose. But the half- life of the Carbon-14 is relatively small as 5730 years. That means the amount of Carbon-14 will be half after every 5730 years. Hence, decay is very fast. So Carbon-14 cannot be used forage determination which is more than 75000 years due to the low accuracy.
Answer:
Dmitri Ivanovsky
Explanation:
Dmitri Ivanovsky utilized one of these filters in 1892 to demonstrate that despite being filtered, sap from a diseased tobacco plant remained infectious to healthy tobacco plants. The filtered, infectious substance was dubbed a "virus" by Martinus Beijerinck, and this discovery is regarded as the origin of virology.
