Answer:
When a new and aggressive species is introduced into an ecosystem, it may not have any natural predators or controls. It can breed and spread quickly, taking over an area. Invasive species can change the food web in an ecosystem by destroying or replacing native food sources.
Explanation:
I majored in Biology
Answer:
In humans, genetic variations are caused because humans reproduce by a sexual life cycle which is termed as meiosis. In such a life cycle, the offspring receives half the chromosomes from the mother and half from the father. Crossing over and random assortment of chromosomes are two phenomenons which occur during meiosis. Due to these two phenomenons, genetic variations are caused.
During crossing over, the exchange of DNA segments between the homologous chromosomes takes place which brings about the genetic variations.
Answer:
Electric current – The net movement of electric charges in a single direction through a wire or conductor. Voltage difference – The force that causes electric charges to flow; charges flow from high voltage to low voltage
Explanation:
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A user mentioned in the comments of one of the answers deleted: "its B" < The user (<span>lolbae0806) had mentioned this...</span>
So I believe the correct answer is:
B.) More oxygen gas became present in the atmosphere.
