The digestive system is necessary for the body's health because it breaks down the food we eat into small pieces that can be absorbed by the body. Without the digestive system, we would not receive all of the nutrients from food.
Example of Internal Stimulus - Option A
A decrease in oxygen levels in the blood during exercise is an example of an internal stimulus. It is happening within the organism itself, it will be internal stimulus. But a sudden change of air temperature is not occuring within the body of organism.
It is the change outside so it is external. An artificial light that attracts insects and an increase in the amount of water available to plant. Both are happenings which occur outside the body hence both are external stimulus. Only a decrease in oxygen levels in the blood during exercise happens inside the body so it is only internal stimulus.
Genes are segments of DNA located on chromosomes. A gene mutation is defined as an alteration in the sequence of nucleotides in DNA. This change can affect a single nucleotide pair or larger gene segments of a chromosome. DNA consists of a polymer of nucleotides joined together. During protein synthesis, DNA is transcribed into RNA and then translated to produce proteins. Altering nucleotide sequences most often results in nonfunctioning proteins. Mutations cause changes in the genetic code that lead to genetic variation and the potential to develop the disease. Gene mutations can be generally categorized into two types: point mutations and base-pair insertions or deletions.
!.) Biodiversity is the variation of a species throughout an ecosystem
2.) Biodiversity forms the foundation of the vast array of ecosystem services that critically contribute to human well-being. and3.) <span>the variability among living organisms from all sources including, inter alia, terrestrial, marine and other aquatic ecosystems and the ecological complexes of which they are a part; this includes diversity within species, between species and of ecosystems.
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