Answer:
7
Explanation:
There are always half the chromosomes in sex cells.
Answer:
Mammals, insects, fish and plants all have different systems of exchanging gas. For mammals we breathe into our lungs, for fish they use gills and insects use spiracles.
Explanation:
hope it kind of helps sorry if it doesn't
Carbon dioxide is added to the atmosphere naturally when organisms respire or decompose (decay), carbonate rocks are weathered, forest fires occur, and volcanoes erupt. Carbon dioxide is also added to the atmosphere through human activities, such as the burning of fossil fuels and forests and the production of cement.