Answer:
D. 3:1
Explanation:
Gregor Mendel, in one of his numerous studies, performed a cross between purebred dominant (TT) pea plants and purebred recessive (tt) pea plants. All the offsprings of this cross appeared heterozygous tall (Tt) in the F1 generation.
However, when he self-crossed the F1 generation i.e. Tt × Tt, Mendel obtained a phenotypic ratio of 3 tall plants (dominant traits) : 1 short plant (recessive). This showed that the masked gene (recessive) was still present.
The correct answer is Galen.
Galen considered anatomy as the foundation of medical knowledge, and he recurrently dichotomized and tested on the lower animals like pigs, sheep, and goats. Galen's supported dissection as the method to better the skills of surgery and research works.
In his work, he illustrated seven pairs of cranial nerves, observed the structural distinctions between the veins and arteries, and illustrated the valves of the heart.
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.
Thick rigid cell wall is not characteristic of a parenchyma cell