A construction worker uses a hammer to drive a sharp nail into a concrete wall. What two simple machines is the construction worker using when he does this task-(D) a wedge and a lever
Explanation:
Simple machines are the tools an individual uses in his day to day life in order to make its work simpler.
For Example: Axles and wheel make it simple to carry a heavy object in a shopping cart.
<u>A hammer is a type of lever,</u>and is also a type of simple machines.A hammer can be defined as a heavy rigid bar moves around a fixed point ,that point is called fulcrum .
Wedges is also a form of simple machine and the inclined plane forms its foundation. A wedge can be referred to as the sharp edge of an inclined plane.They are used to level out a structure of an object
Thus we can say that A construction worker uses a hammer to drive a sharp nail into a concrete wall. What two simple machines is the construction worker using when he does this task-(D) a wedge and a lever
Answer:
Phenotypic plasticity
Explanation:
Humans have evolved over thousands of years to adapt to various environmental changes. For example, when we are in an environment that requires certain level of adaptation our off spring often formalizes epigenetic traits that lows them to overcome small changes in the environment. Over time certain genes that are turned on may remain on and eventually the ones that are off remains off. This give rise to some genes that "don't work" after millions of years of such evolution we end up with a complex genome with more DNA than "working genes".
The blob operon produces enzymes that convert compound A into compound B. The operon is controlled by regulatory gene S. Normally, the enzymes encoded by the operon are synthesized only in the absence of compound B. If gene S is mutated, the enzymes are synthesized in the both the presence AND absence of compound B. Gene S must encode a(n):
a. inducer.
Answer:
IgE
Explanation:
Immunoglobulins can be described as antibodies that are found in blood and other bodily fluids of humans and other vertebrate animals. And their major function is that they help identify and destroy foreign substances such as microbes such as bacteria and protozoan parasites.
They are known to be produced by produced by plasma cells (white blood cells).
Immunoglobulins are classified into five categories: IgA, IgD, IgE, IgG and IgM. And are distinguished by the type of heavy chain they contain. IgG molecules possess heavy chains known as γ-chains; IgMs have μ-chains; IgAs have α-chains; IgEs have ε-chains; and IgDs have δ-chains.
In this case, IgE is the immunoglobulin that attach to and sensitize mast cells and basophils.
Germ-line mutations are mutations that would be passed down to future generations, and recombinations are where the information each parent passes down to the offspring is shuffled.
The genetic variation would have to come from random events: False
Only alternate generations would express any genetic variable: False
Body cell mutations would be the only source of heritable genetic variation: False
There would be no new heritable genetic variation possible in the population: True
