Needles.
Sharing needles or things that you can eject through your skin (ex. drugs)
Infected tattoo needle that wasn't cleaned and disinfected properly
Answer:
Some variation is the result of differences in the surroundings, or what an individual does. This is called environmental variation.
Proton is positive.(+)
Neutron is neutral(0)
Electron is negative(-)
Answer:
Please find the summary of what happens during DNA replication below
Explanation:
DNA replication is the process by which a DNA molecule is duplicated into two identical copies. It occurs in the nucleus of the cell prior to any cellular division. The process includes:
- The double stranded DNA is first unwound by an enzyme called DNA HELICASE into a replication fork consisting of two single strands of DNA.
- Another enzyme called DNA POLYMERASE binds to the DNA and begins to add NUCLEOTIDES to each strand using complementary base pairing rule i.e. A-T, G-C. To do this, short sequences of RNA called PRIMER are synthesized by an enzyme called PRIMASE, which serves as building block for DNA polymerase to act.
- However, DNA POLYMERASE can only work in the 5'-3' direction i.e. on the leading strand which runs from 3'-5' direction. Short pieces of DNA called OKAZAKI fragments are synthesized on the lagging strand, which runs from 5'-3' direction.
- An enzyme called LIGASE joins the okazaki fragments together into a whole DNA on the lagging strand.
After the replication process which follows the SEMI-CONSERVATIVE MODEL of replication, each DNA molecule will contain one old strand called PARENT STRAND and one NEW strand.
