Should be carpentry tools
They carved out part of the hill to make steps. This allows them to grow rice on their hilly landscape. Also since rice requires flooded fields, this system will help lead water to the plants.
Answer:
The rough er has ribosomes attached to it and the smooth er does not
The advantage i see in light microscope when compared to electron is the fact that we can view cells while they are alive and the fact that we have wider range of differential stainings for all types of cells.
In electron microscope the tissue has to be extremely thin and fixed, meaning, dead. So we cant see them like, 'while' they are dividing, we can just catch the fixed state of division. And stains have issue, its harder to deal with stains in electron microscope because of its properties in reflecting them.
These are the ones I saw as important while working in labs.
Answer:
The respiratory and circulatory system functions together to circulate oxygen and blood all through the body. The movement of air takes place in and out of the lungs via the bronchi, trachea, and bronchioles. The movement of blood takes place in and out of the lungs via the pulmonary veins and arteries, which associate with the heart.
The pulmonary arteries mediate deoxygenated blood to the lungs from the heart, and the pulmonary veins carry oxygenated blood to the heart again so that it can be distributed to the rest of the body.