60 years is three half life for the substance, so 40*1/2^3=5
Answer:
Explanation:
1- the purpose of blood flow-circulatory system- is to convey Oxygenated blood, oxygen bonded with haemoglobin in the RBC with Nutrients - and distributed these through the arteries and capillaries away from the heart, to reach the cells and tissues, and transported the wastes of theses cells and tissues , with C02 through the veins back to the heart and the kidney.
2. During diastole,deoxygented blood from the inferior and superior vena cavae entering the R.atrium, passes through the tricuspid valve into the Right Ventricle. Simultaneously, oxygenated blood returning through the pulmonary veins enters the left Atrium,emptied through the bicuspid valve into the Left.Ventricle.
During systole, the two ventricles contracts. The Right ventricle contracts, the pressure of the blood forces the tricuspid valve to close,and therefore de -oxygenated blood pushes the pulmonary valves to open and blood passes through the pulmonary artery to reach the lungs where exchanges of oxygen with carbon dioxide occurs.The blood is now oxygenated and returns to the left atrium via pulmonary veins.
Simultaneously, the left ventricle contracts,the oxygenated blood it contains forced the bicuspid valve to close so that blood is forced through the aortic valve to empty into the aorta into the systemic circulation,branches of the carotid artery supplies the heart from the aorta.
The Whole cycle continues.
<u>Answer</u>:
Option d. many small changes can create a whole new species
<u>Explanation</u>:
In the natural selection when the animals gets adapted in a better manner, they tends to thrive in and gets the ability to reproduce more which leads to the formation of the new bigger species. It leads to a change when the individual with few characteristic have the survival chance more also the reproductive rate as compared to others individuals in the group and also passes these inheritable genetic traits to the offspring.
Answer:
c lunar and solar eclipse
Explanation:
It is 200 million years because it has been around for a long time.
