D) oxygen, carbon dioxide when you breathe in, you take in oxygen and when you breath out, you release carbon dioxide.
Answer:
In 1630 at the beginning of European settlement, about 425,000,000 hectares of the US were forested. By 2017, the area of forested land has declined to 300,000,000 hectares. What is the percent decrease of forested land between 1630 and 2017?
1630= 425000000
2017= 300000000
decrease= 125,000,000
percentage decrease= 125000000/425000000 x 100
percentage decrease= 29.41%
Explanation:
C.
The immune system collects and stores the invading organisms
Mendel crossed the dominant purple colour flowered plant with the recessive white colour flowered plant. The F 1 generation produced the heterozygous purple colour flowered (Pp) plants. When two heterozygous pea plants (Pp) are crossed in the F2 generation represented by Pp x Pp, the gametes formed are P and p. Out of the offspring produced, 3 are purple colour flowered plants and 1 is white colour flowered plant. Thus the phenotypic ratio is 3: 1 with one out of four plants being white colour flowered pea plant. When expressed in percentage it is 25%.