When a pregnant woman ingests toxins such as alcohol and nicotine, the embryo is put at risk because these toxins can
1) diffuse from the mother's blood into the embryo's
blood within the placenta
2) enter the embryo when it eats
3) transfer to the embryo since the mother's blood
normally mixes with the embryo's blood m the placenta
4) enter the uterus through the mother's navel

d.

explanation:

ans.

dna fingerprinting is defined as a process that determines the dna characteristics of an individual. these dna characteristics are unique among individuals as their fingerprints, so it is known as dna fingerprinting.

steps of dna fingerprinting includes extraction of dna from sample, amplification of dna, restriction digestion of amplified dna, and then analysis of dna by gel electrophoresis, respectively.

thus, the next step performed by the scientist is 'to cut the amplified dna (obtained by polymerase chain reaction) by restriction enzymes that cleave the dna into fragments and their analysis.'