Answer:
c. If the double helix were unwound, each nucleotide along the two parent strands would form a hydrogen bond with its complementary nucleotide.
Explanation:
According to the Watson-Crick model, two DNA strands are held together by complementary base pairing wherein each nucleotide of one DNA strand forms hydrogen bonds with its complementary nucleotide present in the other strand. During DNA replication, two DNA strands are separated by the action of helicases enzymes.
The separated DNA strands serve as a template for DNA replication. Here, each nucleotide of the template DNA strand binds to its complementary nucleotide by hydrogen bonds. For example, adenine of the template strand forms two hydrogen bonds with thymine while guanine forms three hydrogen bonds with cytosine.
a because its all living things
Answer:
secrete a cytokine that triggers apoptosis
Explanation:
Cytotoxic T cells secrete granzymes and perforins when targeting cells. Additionally they secrete cytokines such as IFN-, TNF-α and TNF-β that act to activate macrophages and help kill infected cells.
Answer:
500-million-year-old fossil found in BC is ancient ancestor of spiders and scorpions. Palaeontologists in British Columbia have found a fossil of the oldest known ancestor of scorpions and spiders.
Warm fronts
Not cold fronts because those move to warm
