TASK DEFINITION: Combine the given two facts to write a concluding fact. Note that there should be some parts of the first and second facts that are not mentioned in this conclusion fact. Your combined fact should be the result of a chain between the two facts. Chains form when two facts connect together to produce a concluding fact. An example of a chain is: "pesticides cause pollution" (fact1) + "pollution can harm animals" (fact2) → "pesticides can harm animals" (conclusion fact). Parts of the concluding fact overlap with the first and the second fact. To construct such a  concluding fact, a useful way is to borrow the subject from one fact and the ending conclusions from another fact.
PROBLEM: Fact 1: Oxygen is essential for cellular respiration for all aerobic organisms. 
Fact 2: Less oxygen for the mother means less oxygen for the baby.

SOLUTION: Mothers need respiration for their babies.

PROBLEM: Fact 1: Mammals can also generate little bursts of heat by shivering. 
Fact 2: All humans are mammals.

SOLUTION: humans can generate little bursts of heat by shivering.

PROBLEM: Fact 1: Echinoderms lack a centralized nervous system. 
Fact 2: All echinoderms are deuterostomes .

SOLUTION:
Some deuterostomes lack a centralized nervous system.