17=3
18=4
I'm not that sure about 17, but I think it's right
Answer:
Explanation:
Fundamental niche is the entire set of conditions under which an animal (population, species) can survive and reproduce itself. Realized niche is the set of conditions actually used by given animal (pop, species), after interactions with other species (predation and especially competition) have been taken into account
Unoxygenated blood from veins enters the right atrium then it goes down to the right ventricle then out through the pulmonary artery to the lungs where it becomes oxygenated blood which then enters the heart through the pulmonary veins and it goes to the left atrium and then is pumped down to the left ventricle and out through the aorta to the arteries where it travels to different organs and becomes deoxygenated and then the cycle repeats itself.
The skeletal muscles have striations to do their sacromere anatomy
sacromere which are formed by actin and myosin stacking
sarcomere is the functional unit of muscles and shows striated appearance due to thick and thin filaments
hope it helps