(I don't know if this is right) Being lighter than air relates to density. There are also other noble gas elements with density lighter than air, such as helium. I would fill it with helium and regulate the amount due to the air pressure and altitude wanted/needed. This could be a good response for a middle school course, but if you need an extended response, then provide some scientific terms too.
Answer: In genetic term, evolution can be defined as any change in the frequency of allele in a population over a period of time.
Natural selection usually brings about changes in the genetic variation of a population of organisms over a period of time, this process might lead to speciation, which is formation of a new specie that is distinctly different from those that had been existing before. Genetic evolution through natural selection usually enhance an organism's ability to survive' in its environment.
Answer:
Mitosis happens in all eukaryotic cells (plants, animals, and fungi). It is the process of cell renewal and growth in a plant, animal or fungus. ... Mitosis is also important in organisms which reproduce asexually: this is the only way that these cells can reproduce
Explanation:
Answer:
Red blood cell has lot of haemoglobin to carry more oxygen