Question

1.carbon

2oxygen
3.nitrogen
is an element found in all organic molecules. During respiration, animals excrete it as a gas known as . 1 NH4
2 O2
3. CO2

Answer 1

1st=Carbon

2nd=CO2

Hope it's right!

Answer 2

1. Carbon

2. CO2

Step-by-step explanation:

1. All living things are made of inorganic molecules mainly carbon and hydrogen. These two elements form the backbone of hydrocarbons which are considered as the building block of living things

2. During respiration in living beings (animals and human beings), the oxidation of carbohydrates takes place in which glucose is break down into carbon dioxide and water.