I think the answer to this would be A
Answer: All the above options are correct about the characteristics of Lumbriculus variegatus.
Explanation:
Lumbriculus variegatus also called the black worm belongs to the phylum Annelida and is used by biologists to illustrate:
-blood vessel pulsations,
-swimming reflex,
-peristaltic crawling behavior,
-giant nerve fiber action potentials.
These studies where carried out on them due to the characteristics they possess. These includes:
-its blood circulates in a closed circulatory system
-Freshwater worm found throughout North America and Europe
-Prefers the shallow habitats found at the edges of ponds, lakes, or marshes
-Feeds on decaying vegetation and microorganisms.
Answer:
The pH of a solution containing 0.1 mM H+ is 4
Explanation:
The pH of any solution is given by the following mathematical equation -
----------- Equation (A)
Where,
= the concentration of hydrogen ion in the solution.
Given
= 
Substituting the given value in equation (A) , we get -
![pH = -log[10^{-4}]](https://tex.z-dn.net/?f=pH%20%3D%20-log%5B10%5E%7B-4%7D%5D)

Hence, The pH of a solution containing 0.1 mM H+ is 4
Answer:
No.As we know that phenotype depends on physical appearance whereas genotype is genetical materials. So person having same phenotype doesn't mean they have same genotype.