The answer is the option "c"
The eruptions are caused by an accumulation of gases that press under a volcano.
The molten rock continues to generate upward pressure but can not advanced; this causes that its force increases with the passage of time, since it continues accumulating hot gases trying to come to the surface.
Finally, the surface yields and a volcanic eruption occurs.
There are 6 elements that are the most important. The acronym, CHNOPS, is an easy way to remember these.
C - Carbon
H - Hydrogen
N - Nitrogen
O - Oxygen
P - Phosphorous
S - Sulfur
Answer no 8:
The correct option is D) Antelopes with muscular legs are bale to outrun their predators better than antelopes with poor muscle tone. Thus they lived to reproduce.
Explanation:
Genetic variations in a population are the main reason that natural selection tends to occur. Natural selection favours those organisms which have better characteristics.The organisms with better traits are able to reproduce and pass on their characteristics to their offsprings.
Answer No 10:
The correct option is A) Phenotype directly influences the interaction of an organism with its environment.
Explanation:
The interactions between the phenotypic traits and the environment analyze whether a particular organism will be able to survive and pass on its characteristics to its offspring. Hence, the phenotype directly influences the interaction of an organism with its environment.
Answer No 9
The correct option is A) resistance to a virus
Explanation:
Mutations can be described as any changes which occur in the DNA of an organism. Mutations might be beneficial or harmful depending on the location where the mutation arises. Viruses are usually harmful for eukaryotes. Hence, the correct option is A.
Answer No 11:
The correct option is C) Giraffes with longer necks survived because they were better suited to the environment.
Explanation:
Natural selection tends to favour those organsims which are better suited to live in an environment. Those organisms with better characteristics are able to survive and pass on their traits to their offsprings.
The giraffes with longer necks were better adapted to live in the environment and hence were favoured by natural selection.
Answer No 12:
The correct option is D) selective breeding
Explanation:
Selective breeding can be described as a technique in which organisms with better characteristics are crossed, so that offsprings with better characteristics can be produced. Selective breeding is done by humans where as natural selection is done by the nature.
Answer:
I'm assuming you meant pool instead of poolon, i'll take it as a grammatical error. Anyhow, the water in a pool on sunny days tend to have less chlorination then on regular days. This is because chlorine forms hypochlorite ions in the water, and these are broken down by the ultraviolet light from the sun. Rainy or shiny, the weather is always affecting the chemistry in your pool.
Now, if you want to get more complicated into it, you can add a stabilizer into the pool. The common one safely used in pools is cyanuric acid. This almost completley prevents all de-chloronification.
I hope this information was of any use to you.