2 Sodium fluoride is the answer
Answer:
d. Under normal circumstances, each chromosome contains precisely one gene.
Explanation:
The gene is a segment of a DNA molecule, responsible for genetically inherited traits. Each gene consists of a specific DNA sequence that contains a code (instructions) to produce a protein that performs a specific function in the body. Each human cell has about 25,000 genes.
The genes are located within the chromosomes. A chromosome can house thousands of genes, it is not normal for a chromosome to house a gene or a few units. Thus, if a cell contains 46 chromosomes, that cell has an incalculable number of genes.
B. Similar bacteria or protozoa which group together.
Answer:
A. Ancient bacteria
Explanation:
From the salt of the earth, researchers have isolated and revived a Bacillus strain, which they believe is >250 million years old. If correct, Russell Vreeland and his colleagues from West Chester University, Pennsylvania, have discovered the oldest living organism in the world.
Answer: comparison of DNA and proteins
Explanation: