Answer:
The ability of chemotherapy to kill cancer cells depends on its ability to halt cell division. Usually, cancer drugs work by damaging the RNA or DNA that tells the cell how to copy itself in division. If the cancer cells are unable to divide, they die.
So here we have two heterozygous organisms that will mate. You can put them into a Punnet square, just to be sure of your answers and to find all possible genotypes :
R r
R RR Rr
r Rr rr
So you have RR, Rr and rr as your possible genotypes.
The correct answer is: marsupials.
Marsupials are actually defined by their ability to hold the young in the pouches, where they can be well protected. Some examples are Kangaroos and Koalas.
Other answers are wrong: for example, gymnosperms are plants, not animals.
