Answer:
Independent Variable:
temperature
dependent variable:
chirps
Hypothesis:
the lower the temperatures the less chirps
constants:
temperature or food and water
repeated trails:
success and failure
control:the experiment
+ not having enough food for everyone
+ how many people migrate
+ birth/death rates
+ how much water there is
+ how much nutrients/minerals are available
+ how much trees/oxygen is available
Answer:
Blastocyst,Blastoderm
Explanation:
The blastula is made up of a hollow spherical layer of cells, referred to as the blastoderm which surrounds a yolk or fluid-filled space called the blastocele or blastocoel. In most mammals, including humans, the structure formed next is the blastocyst, a mass of inner cells that are distinct from the blastula
Answer:
The return of blood to the heart is assisted by the action of the skeletal- muscle pump. As muscles move, they squeeze the veins running through them. Veins contain a series of one-way valves, and they are squeezed, blood is pushed through the valves, which then close to prevent backflow.
It has been estimated that active tobacco smoking causes close to 90% of lung cancer cases and is the cause of 87% of lung cancer deaths.