Hookworms, live, mosquitoes, and ringworms
Upto 50%of human conceptions fail before the little guys can swim successfulllyinto the egg and be home free :)
Answer: x+y=21, 3x+4y=68
Explanation:
Here x represents the number of small button and y represents the number of large button,
And, According to the question,
Total number of button = 21
Thus, x + y = 21
Also, She sells the small buttons for $3 and the large buttons for $4, and earns a total of $68
That is, 3x + 4y = 68
Thus, the system of equations that can be used to calculate the number of large and small buttons sold are,
x + y = 21, 3x + 4y = 68
First Option is correct.
Answer:
Explanation:
Duchenne muscular dystrophy acts as a X-linked recessive disease. Which means the gene sits on the X chromosome, and you need two bad copies to show disease (for females) and one bad copy (to show in males).
Now from our knowledge, we know males are XY and females are XX. Males have only one copy of the X chromosome from their mother and one copy of the Y chromosome from their father, thus if they get the mutated version of the gene that causes this disease, they will get the disease. However, if a female has a mutated version of gene on one of the X chromosome, the other X chromosome could have a normal gene and that normal gene would take over and produce a normal phenotype/function.
Since, boys only have one X chromosome, if they get the mutated gene they will get the disease, whereas females have two X chromosome (so even if one copy is bad and the other is good, the good version can take over, however boys don't have this) thus mostly male children are affected by this.