Answer:
Non-coding DNA regions play important roles in regulating transcriptional activity by encoding different types of non-coding RNAs (ncRNAs), acting as scaffold attachment regions, acting as enhancer specific regions, etc.
Explanation:
Historically, it had been believed that non-coding DNA sequences were 'junk DNA' since they don't encode for proteins (beyond the sequences that are transcribed into functional non-coding RNAs, i.e., transfer RNA and ribosomal RNA). However, in the last years, it has been shown that non-coding DNA sequences play critical roles in regulating gene expression and genome function. For example, evolutionary conserved non-coding RNAs (ncRNAs) with regulatory roles on gene expression such as, for example, long non-coding RNAs (lncRNAs) and microRNAs (miRNAs) have been mapped in non-coding DNA sequences, thereby evidencing the functional significance of these regions. In consequence, the conservative nature of certain non-coding DNA sequences evidence that mutations in such regions may have significant deleterious effects, and thereby they could have a negative impact on the fitness of the individual.
Answer: 23
Explanation: One pair of the 23 chromosomes, known as sex chromosomes, determines at conception whether a fertilized egg will develop into a male or female. Today, human females have one pair of identical X chromosomes.
False. Energy is only released when chemical bonds are formed.
The correct answer is - C and D.
The principle of original horizontality means that the rock layers have been order by age, with the layers at the top being the youngest, while the layers at the bottom being the oldest.
In this picture it is little hard to tell which rocks belong to the same layer from first look because there are multiple twists and turns, an uneven surface, caused by pressure on the crust.
By carefully examining the image though, we can trace the layers more properly and see which ones are younger, which older, and which have the same relative age. In this case, we can see that the markings C and D are actually on the same layer of rocks, thus being a good indication that they have the same relative age.
Answer:
an autotroph is a <em>producer</em> in the food chain
Explanation:
An autotroph produces its own food from light, heat, and/or environmental chemicals, often including water and/or carbon dioxide. It is a <em>producer</em>, not a consumer, in the food chain.
