The body system responsible for the exchange of gases between the body and environment is the

Answer:

B. There are two main categories of the tundra biome.

Explanation:

Answer:

A

Explanation:

peroidt pooh

Answer;

C. the plant is producing oxygen

Explanation;

-Scientific inference is the conclusion of a hypothetical-deductive argument after the experiment is conducted. Inference is the process used in forming a hypothesis and it combines something you observe with your previous knowledge.

-An inference is an idea or conclusion that's drawn from evidence and reasoning. An inference is an educated guess. We learn about some things by experiencing them first-hand, but we gain other knowledge by inference.

Answer:  Portions called introns are removed and the remaining exons are spliced together

Explanation:

The messenger RNA obtained after transcription is known as primary transcribed RNA or precursor RNA, and it has to undergo modifications before exerting its function. This is called RNA processing or maturation.

In the DNA sequence, the coding content of a gene is not continuously distributed along the gene, but has discontinuities, called introns, whose sequence does not encode proteins.The parts of the sequence that encode proteins are called exons. Through a process called splicing (which is one of the modification that are part of the RNA maduration), the introns are eliminated and the exons are joined forming a mature messenger RNA molecule that will be used for protein synthesis.

So the exons are part of the region of a gene that is not separated during the cutting and splicing process and is therefore kept in the mature messenger RNA. Each exon codes a specific portion of the entire protein, so that the set of exons forms the coding region of the gene.