The right answer is B) gene.
A gene, in genetics, is a basic unit of heredity which in principle predetermines a specific trait of the form of a living organism, as defined in 1909 by Wilhelm Johannsen. From the physical point of view, a gene is a fragment of the determined locus of a DNA sequence.
A gene "parameter" the synthesis of a given RNA, by predefining its structure and, therefore, that of the possible protein or possible polypeptide synthesized from this RNA: this is what molecular biology studies .
These two aspects of the notion of gene are supposed to correspond, one at the physical and molecular level, the other at the level of principle and heredity.
<span>mtDNA analysis is the best DNA technology to use. In DNA fingerprinting scientists run a gel electrophoresis of the subject's DNA in order to establish the banding patterns of the DNA fragments. People will always share half of their DNA with a parent. SO half of an individual's banding pattern will match half of their parent's DNA banding pattern. If someone is missing is found then scientists can compare the DNA fingerprint or banding patterns to see what the likelihood is of them being related.</span>
Eliminate B and D, not all single celled organism carry out through photosynthesis , they called singled celled organism and not work with other cell, it's either A and C, single celled organism is not a complex organism. so you can eliminate letter C.
so the best answer is A, although they have multiple organs system to maintain their internal stability.
Answer:
It means that the cell membrane only lets some molecules/substances through the phospholipid bilayer.
Explanation: