Study the timeline. A timeline. 4.5 billion years ago, Earth is formed. 4.3 billion years ago, Earliest water. 4.1 billion years ago, Single celled life. 3.5 billion years ago, Earliest oxygen and photosynthesis. 2.5 billion years ago, Complex single celled life. 1.5 billion years ago, Multi cellular life. 500 million years ago, Land life. 300 million years ago, Dinosaurs. 200 million years ago, Mammals. 130 million years ago, Flowers. 5 million years ago, Humans.

Based on fossil evidence, about how long ago did the first single-celled life form appear on Earth?

130 million years ago
1.5 billion years ago
2.5 billion years ago
4.1 billion years ago
ITS 4.1 BILLION YEARS AGO!

1. emigration the movement of people from one place to another 2. immigration a situation in which resources are being used up at a faster rate than they can be replenished 3. migration the leaving of one's homeland to settle in a new place 4. overpopulation the movement of people to a new country 5. sustainable development a situation in which the birth rate is not sufficient to replace the existing population 6. underpopulation the ability to meet current needs without reducing the ability to meet future needs 7. unsustainable development the increase in the population of a city 8. urbanization a situation in which the number of people exceeds the available natural resources in an area

Plz ! a frog has a genetic mutation in skin cells that causes part of its skin to turn orange the frog will not pass this genetic mutation onto its offspring because, a. the offspring will inherit skin cells from the other parent. b. mutated skin cells cannot divide and produce daughter skin cells. c. skin cells do not contribute genetic material to sex cells. d. parents do not contribute genetic material to their offspring.

Wich organism obtains its energy from dead or decaying matter