Answer: Option C.
Macroevolution is a change in allele frequencies within a population.
Explanation:
Microevolution is the change in allele frequencies within a population over time. Microevolution is caused by four processes which are natural selection, artificial selection, gene flow and gene drift and these are referred to as fundament forces of evolution.
Answer:
Superior vena cava
Explanation:
Of the two vena cava, the superior vena cava is the large vein without valves that is responsible for conveying de-oxygenated blood from the upper extremities and body (neck, chest, arm and head) above the diaphragm to the right artrium.
Although the superior vena cava is a large vein, it also short; it is about 2 cm wide and 7 cm long.
When there is an obstruction of the superior vena cava, it can result to the enlargement of the veins and could lead to chest pain and breathlessness.
True! because without gravity the spacecraft wouldn't go where there wanted it, in the time that they wanted it
Why did you write the last part I don’t get it I’m