Answer:
Hi there!
Your answer is:
It is very important for the cell membrane to be <em>semi-permeable</em> because the ability to pick and choose what comes in and out of the cell keeps the cell safe! The membrane can choose to block out nasty germs and can also choose to get rid of internal waste.
An example of when this is important is in this scenario:
Let's say the cells are in a really salty solution. Naturally, salt will want to pull the water out of the cell. If the membrane <u>wasn't</u><u> </u> semi permeable, the water would listen to the salt and leave the cell. This would cause cell death. <u>BECAU</u><u>SE</u> the membrane is semi permeable, they can choose <em>not</em> to give the salt any water, keeping them alive
Hope this helps
Answer: b. Muscles
A metazoa is a division of animal kingdom that includes all animals expect protozoa and sponges. Metazoa division includes multicelluar animals, which exhibit highly differentiated cells. They have muscular and nerve system and well coordinated tissues and organs. Locomotion requires a coordination activity of muscular, skeletal and neural system. It is mainly achieved by contraction and relaxation of muscles that occurs due to specialized muscle proteins named as actin and myosin which receives signals from nerves.
Hence, locomotion in metazoa is due to contraction of muscles.
Answer:
In a homogenous mixture all the substances are evenly distributed throughout the mixture (salt water, air, blood).
Explanation: i think this is right
