1. What were the conditions on the planet when life began?

The early Earth had no ozone layer and was probably very hot. The early Earth also had no free oxygen. Without an oxygen atmosphere very few things could live on Earth. Anaerobic bacteria were probably the first living things on Earth.

humans are now responsible for causing changes in the environment that hurt animals and plant species. we take up more space on earth for our homes and cities. we pollute habitats. human activity often changes or destroys the habitats that plants and animals need to survive.

the correct answer is: d. the saltine and pretzel are made of flour, yeast, and baking soda, and salt. the pecan contains no flour but it does contain fats. the pecan is a nut that can be consumed as a healthy snack. first of all, pecans are a source of fat (monounsaturated fat), but they provide less fat than some other nuts. pecans are a rich source of dietary fiber, manganese magnesium, phosphorus, thiamin, vitamin e…