The remains or impression of a prehistoric organism preserved in petrified form or as a mold or cast in rock.
Mold fossils
Cast fossils
Trace fossils
The basic repeating unit of nucleic acids are known as nucleotides. A nucleotide consists of three distinct chemical groups, a 5-carbon sugar (ribose or deoxyribose), a nitrogen-rich base - (cytosine (C), guanine (G), adenine (A), thymine (T) in DNA or uracil (U) instead of T (in RNA), and phosphate.
Answer:
Bacteria that entered an organism body can cause mutations by altering the gene
This is the process of DNA replication :
Cells Can Replicate Their DNA Precisely. Replication is the process by which a double-stranded DNA molecule is copied to produce two identical DNA molecules. DNA replication is one of the most basic processes that occurs within a cell. ... To accomplish this, each strand of existing DNA acts as a template for replication.
hope this helps .
