Answer:
Petrified fossils are formed when minerals replace all or part of an organism.
Answer: a cell membrane
Explanation: But remember that bacteria do have their DNA inside their protein envelope. They don’t have a nucleus, but they do have DNA making them also have the ability to reproduce.
Answer:
In the adult heart, blood in the right chambers of the heart cannot enter the left chambers without passing through the lungs. (Ans. A)
Explanation:
In heart, heart muscle cells is responsible for the circulating the blood throughout the body. The heart contains four chambers, two upper called as atrium and two lower called as ventricle, 1 atrium and 1 ventricle present on both right and left sides of the heart.
Blood which is returning from other parts of the body and is no longer oxygen rich, enters from the top right chamber of the heart. Than this blood is pumped into the right vertical and through the pulmonary artery into the lungs for absorb more oxygen.This oxygen rich blood is then pumped into the top left chamber present in the heart, and then into the lower left chamber before being pumped out into the body from the aorta.
So, the answer is A.
Answer:
The mouse will because it has the higher surface-area-to-volume ratio.
Explanation:
The living organisms maintain their homeostasis by maintaining their internal constant environment as external environment changes. These organisms are known as exothermic animal.
The surface area to volume ratio in case of living organisms plays an important role. The small species has high surface area to volume ratio as compared to the larger species. The diffusion, cooling and other process is faster in the small size species. The mouse body will get cool faster than elephant species.
Thus, the correct answer is option (3).
