What holds the two strands of DNA molecules to each other. Hydrogen Bonds
Answer:
The colonies are carrying the resistance genes from plasmids
Explanation:
Bacteria can acquire beneficial characteristics that they didn’t have. One way for these is through plasmids, which ones are little fragments of DNA that usually contains resistance genes (for antibiotics, disinfectants, heavy metals, etc.) or other capacities, like the ability to use some substances (for example sugars).
In this specific situation, we already know that the plasmid carrying genes for tetracycline resistance and the <em>lacZ</em> gene.
A little explanation:
Tetracycline is an antibiotic that inhibits bacterial growth and kills the bacteria. The bacteria can “fight” to this antibiotic if it has a resistant gene, the result is that the antibiotic can’t affect the bacteria and survive. An analogy is like a Police Officer (bacteria) that have a bulletproof vest (tetracycline-resistant gene) so the bullets (tetracycline) didn’t affect the police.
In the case of X-gal, is a compound consisting primarily in one sugar called galactose. Not all bacteria can eat galactose, they need an enzyme called β- galactosidase (comes from <em>lacZ</em> gene) that helps the bacteria “eat” the sugar (cuts the sugar in little pieces so the bacteria can eat).
Then, as the bacterial colonies can grow in the medium with tetracycline and X-gal, we know that those bacteria are carrying the resistance genes for tetracycline (does not affect the bacteria) and the <em>lacZ</em> gene (bacteria produce β- galactosidase that cuts galactose). These genes are coming from the plasmids because we already know that the plasmid carries these genes and not from the exogenous DNA.
Answer:
Darwinism is a theory of biological evolution developed by the English naturalist Charles Darwin (1809–1882) and others, stating that all species of organisms arise and develop through the natural selection of small, inherited variations that increase the individual's ability to compete, survive, and reproduce.
Explanation:
Answer: One parent is IAi and the other parent is IBi
Explanation: As this trait is codominant, the child can inherited IA, IB or i.
Tina has type O, which means she is ii and her sister is AB, so her genotype is IAIB. Now, to have a child with a recessive trait both parents has to carry at least one allele for the recessive, i. Rosa is type AB which means she had to have inherited one allele IA from one of her parents and the other IB from the other parent. Thus, one parent is IAi and the other is IBi.
