D is the correct answer :)
<u>Answer</u>: The answers are matched as follows:
African forests have been hunted to near extinction levels to obtain ivory-------------->human exploitation
The eruption of mount Saint Helens destroyed some populations of conifers------> natural disasters
An infection with a fungus reduced the population of North American Elm trees ----> disease
Increasing global temperatures have altered migration patterns of humpback whales ------>climate change
<u>Explanation</u>:
- <em>Human</em> <em>exploitation</em> is the unethical or selfish use of resources to satisfy their own personal needs or for any profitable activity which harms the resources in such a way that they get limited. Humans have been hunting elephants to obtain ivory for many purposes such as making jewellery etc. and earning profits from it. Due to such extensive hunting they have driven the elephants to a level of extinction and thus, this is a form of human exploitation.
- Mount Saint Helens is a volcano and its eruption which harms the population of the trees in the area is a form of natural disaster since volcanic eruption is a <em>natural</em> <em>phenomena</em>.
- Fungal infection is a <em>disease</em> which is cause by the microorganisms which harms the population of the Elm trees.
- Increase of global temperature is a type of climate <em>change</em> and thus, this effect of alteration of migration pattern is caused by climate change.
Answer:
A mutation in <u>DNA </u>results in a change in <u>RNA </u>that sometimes produces a <u>protein </u>with altered structure and function.
Explanation:
DNA is the hereditary material which causes gene expression in our body by producing protein. The type of protein which is produced by DNA totally depends upon the sequence of nucleotides in the DNA. But, DNA molecule does not produce protein directly. Initially it produces RNA (mRNA, tRNA, rRNA) by the process of transcription, the nucleotides in the RNA are complimentary to those in DNA. In short, the message regarding the structure and composition of the type protein to be produced by DNA is first decoded from DNA in the form of RNA. These RNA molecules then synthesize the protein as per the instructions from DNA by the process of translation.
But, in case a mutation occurs in the DNA which causes a change in it's nucleotide/nucleotides, the protein which will be produced will be different in the structure and function than the protein which was supposed to be synthesized. It happens because, a triplet of nucletiodes in the DNA and hence RNA specifies a particular type of amino acid and several amino acids are joined in a long chain to form polypeptide which ultimately forms protein. But, if any nucleotide in the triplet is changed due to mutation it may change the amino acid and if amino acid will change the protein will also get altered.
Surprisingly chocolate actually contains a fair amount of iron. Red meats are known to contain iron, one thing in particular is blood (yes that is sometimes eaten, and it contains a lot of iron). Such organs of animals that are high in iron include the spleen and or marrow.
If you wish to go vegetarian red veggies tend to be high in iron, one in particular are beets (yes, i know, they aren't red until processed)
