The first step begins with: A. the mouth.
Answer: A PEDIGREE is a family-tree like representation of how organisms are related based on ANCESTRY. It shows genetic relatedness or blood relationship between individuals or organisms.
Explanation: Pedigree can be used to determine
1. Family history or genealogy.
2. Genetic or blood relationship.
3. Coefficient of relationship.
4. Degree of relationship.
5. Proportions of shared genes.
6. Mode of transmission of diseases.
7. Risk evaluation or determination.
Genetic counseling.
8. Linkage analysis.
Pedigree symbols are used in constructing pedigree.
The answer is <span> b) chromosomes replicate
DNA replication occurs before mitosis. So, duplicated chromosomes are already present in mitosis. They are connected by centromeres. During different phases of mitosis, spindles are formed and pull chromosomes toward the opposite poles of the cell so centromeres must split.</span>
Reactions that hydrolyze the phosphodiester bonds split the DNA molecule between the phosphate groups and the hydroxyl groups of the two sugar groups.
In DNA there is a covalent bond through a phosphate group that connects the hydroxyl group (OH) at the 5' position of the pentose sugar and the hydroxyl group at the 3' position of the pentose sugar of the next nucleotide. This covalent bond is called a phosphodiester bond because chemically the phosphate group is in the diester form.
In other words, the phosphodiester bond connects the sugar in one nucleotide to the sugar in the next nucleotide, so this bond simultaneously connects the two consecutive nucleotides to form a polynucleotide chain. If there is an enzyme that catalyzes the hydrolysis of covalent bonds that combine nucleotides, what happens is that the phosphodiester link between deoxyribose sugars will break.
Learn more about the phosphodiester bonds at brainly.com/question/23660733
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