Explain the method scientists use to study how earth’s atmosphere and climate have changed during the past million years.

There are various methods that scientists have applied in order to understand the earth's changing atmosphere and climatic conditions are as follows-

(1) By studying the tree rings, which describes that the broader tree rings indicate a wet and warmer temperature, whereas, close and thinner rings indicate a dry and colder type of climate.

(2) Dating the ice core samples and obtaining the data, the scientists have determined the time when the large thickness of snow has accumulated in the past, depicting a very cold climate in the past.

(3) The study of pollen grains that were eroded and deposited at the bottom of an ocean, lakes, and seas also provides a good piece of information regarding the ancient climate.

(4) Coral reefs have been deposited very recently, about 5000 to 10000 years back, which were formed in the tropical climatic condition.

These are some of the ways by which the scientists were able to construct the palaeoclimate.

trachea, alveoli, lung capillaries, arteries

the answers are as following:

1. c. double helix, nucleosome, coil, supercoil, chromosome

2. b. g2 phase, preparation for mitosis

3. d. interphase consists of the g1, s, and g2 phases

4. c. metaphase

5. a. chromosomes are duplicated before cell division so that each new daughter cell has a complete set