Answer: Option B.
A see saw, chin raise.
Explanation:
A lever is a machine that can rotate and consist of a beam which is pivoted to fulcrum.
There are three classes of lever, the first class lever, second class lever and third class lever. These three classes of lever are classified base on the positions of effort, fulcrum and Load.
In first class lever, fulcrum comes between the effort and load. Examples is scissors , see saw, pliers. This is because effort is applied on the one side of the fulcrum and load is on the other side. Therefore, the childhood demonstration of first class lever motion is see saw and chin raise.
In the second class lever, load come between effort and fulcrum e.g wheelbarrow, bottle opener.
In the third class lever, effort comes between fulcrum and load e.g hammer, broom.
Answer:
characterized by presence or absence of antigens
the blood types are A, B, O, AB
Explanation:
There are two antigens and two antibodies that are mostly responsible for the ABO types. The specific combination of these four components determines an individual's type in most cases. Erythrocytes and serum were related to the presence of antigens on these erythrocytes and antibodies in the serum. these antigens are A and B, and depending upon which antigen the erythrocytes express, blood either belonged to blood group A or blood group B. A third blood group contained erythrocytes that reacted as if they lacked the properties of A and B, and this group was later called "O" blood group. The fourth blood group AB, was added to the ABO blood group system. These erythrocytes expressed both A and B antigens.
Blood group Antigen present on RBC Antibodies in serum Genotype(s)
A antigen A anti-B AA or AO
B antigen B anti-A BB or BO
AB both A and B antigen none AB
O none anti-A and anti-B OO
Answer:
A pure culture consists of only one type of microbe while a mixed culture has two or more than two microbes.
Explanation:
A pure culture consists of only one type of microbe.
While a mixed culture consists of more than one type of microbes. such cultures may comprise of different species of bacteria or a group of bacteria, viruses and other pathogens.
In mixed culture the microbe species living together may harm each other existence.
Answer:
The hydrosphere refers to the water on the earth crust. If there were no hydrosphere, we would not have lakes, oceans, rivers, or even a hose full of water.