The answer is B, because sound waves vibrate through mediums (such as liquids, solids, and gas). It can’t travel through a vacuum because there would be no molecules to vibrate.
The nucleotide sequence on a section of
DNA where transcription begins is called a promoter.
To add, i genetics, a promoter is a region
of DNA that initiates transcription of a particular gene. Promoters are found along
the transcription beginning sites of genes, on the same strand and upstream on
the <span>DNA.</span>
Answer:
C) They are compressed during inhalation.
Explanation:
Birds breathe through rigid lungs that are located in the animal's thoracic region. The trachea of birds divides into bronchi that branch inside the lungs into very thin tubes called parabronchials or parabroncholes, which are irrigated by blood capillaries that allow gas exchange.
In birds there are no pulmonary alveoli (as in mammals), but air capillaries that depart from the parabroncholes. Oxygen gas passes from these capillaries to the blood capillaries, thus causing gas exchange.
In the lower portion of the bird's trachea, before branching the bronchi, we can find the syringe, a bag-like structure that has vocal cords responsible for the birds' scream and song. Most of the time, the sound emitted by birds serves to attract the mate, mark territory and prevent birds of the same species against some predator or other danger.
