Earth's early atmosphere: made up of nitrogen and carbon dioxide gases.Animal cell: type of cell that dominates most of the tissue cells in animals. Animal cells are different from plant cells because they don't have cell walls and chloroplasts, which are relevant to plant cells.Plant cell: basic unit of life in organisms of the kingdom Plantae. They are eukaryotic cells, which have a true nucleus along with specialized structures called organelles that carry out different functions.
cells are smallest structural and functional unit of an organism. They make are life better by Cells provide structure for the body, take in nutrients from food and carry out important functions
photosynthesis requires carbon dioxide and releases oxygen, cellular respiration requires oxygen and releases carbon dioxide
biology issues:biological impact of environmental change, genes and genomes, biodiversity and evolution, populations, ecology and conservation of species and natural habitats.ecology:the branch of biology that deals with the relations of organisms to one another and to their physical surroundings.cell:the smallest structural and functional unit of an organism, typically microscopic and consisting of cytoplasm and a nucleus enclosed in a membrane. DNA: deoxyribonucleic acid, a self-replicating material which is present in nearly all living organisms as the main constituent of chromosomes. It is the carrier of genetic infoHormones: a regulatory substance produced in an organism and transported in tissue fluids such as blood or sap to stimulate specific cells or tissues into action.