Use the timeline on the previous page to Read each question, and write 5. Name a

Question

Use the timeline on the previous page to Read each question, and write 5. Name an organism that is seriously damaging Earth's ecosystems, answer questions 6-9 your answer in the space provided. describe some of the damage being caused by this organism. 6. What are some factors that have caused the dominant life-forms on Earth to change over time? 7. Is another major mass extinction likely? Explain. 8. What environmental changes affected the evolution of reptiles? 9. What effect did photosynthetic cyanobacteria have on Earth's environment?

Explanation / Answer

1. Cyanobateria first begin to carryout phtosynthesis.

2.Plant and fungi invade land for first time.

3.Reptiles evolve from amphibians and become dominent on land.

4.Birds and mammals become dominant on land.

5. Human. damages are- Overpopulation,Pollution,Global Warming,Climate Change,Ocean Acidification ,Deforestation,Ozone depletion etc.

6. Mass extinctions-Every time Earth has had a mass extinction, it is followed by a rapid evolution of new species,we lose a lot of species but we also have opportunities for new species.

Continental drift- Continents don't stay put in one place, they tend to move around on earth's surface. When they moves, the climate changes occur on the continent and the species will have to adapt to the new climate in order to survive.

7. Yes, it is a periodic thing and occured in past over a period of time .Many scientists believe that the next mass extinction has already began.The rate of species extinction is extremely high as many species are extinct or going to be extinct. More likely humans may be the cause of the next mass extinction as they depleting natural resources at faster rate for their own benefits.

8.Earth went through a large period of hot and dry conditionswhich leads to a wide spread drought.Drought conditions favored reptiles and they evolved during those conditions and adapted to them.

9. Cyanobacteria added oxygen to the atmosphere for the first time and make it oxidising environment. Oxygen atoms combined and form ozone which enable life on land as ozone blocked out the ultraviolet radiation,which are harmful for life.

Related Questions

Navigate

• Browse (All)
• Browse U
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.