Answer:
The correct answer is B.
Explanation:
Option A is wrong. Mammals were not the prominent species before the extinction of dinosaurs because the mammal species that lived during the dinosaurs' era were so small that they only weighed several grams and occupied small areas as their habitats.
Option C is wrong. As dinosaurs became extinct, reptiles and "birds" remained as their descendant which evolved to some of the species that we know today.
Option D is wrong. Pangea started to break up to form the geographic isolation for the diversion of many species around 175 million years ago.
So the correct answer is B. Massive extinction disrupts and changes the food chain in such a big way that it triggers a domino effect that leads to species adapting to their new environment and diversifying thus forming new species in the process.
I hope this answer helps.
They are ineffective against viral infections because viruses can not be treated with antibiotics.
Answer:
D. pituitary gland
~+. lil more info .+~
The circulatory system consists of three independent systems that work together: the heart (cardiovascular), lungs (pulmonary), and arteries, veins, coronary and portal vessels (systemic). The system is responsible for the flow of blood, nutrients, oxygen and other gases, and as well as hormones to and from cells.
The substances that protect against oxidative stress and the resultant tissue damage at the cellular level is, option B. Antioxidants. Oxidation can cause imbalance in the body. Antioxidants are used to counteract the damage produced by free radicals. Good natural sources of antioxidants include fruits and vegetables.
Answer:
See the eplanation below, please.
Explanation:
In sickle cell anemia, hemoglobin has the form of rigid bars inside the red blood cells, causing them to adopt sickle shapes being not very flexible. These cells can block blood vessels, stopping the flow, causing oxygen to not reach the tissues.
The cause of this anemia is due to a genetic mutation (there is a substitution of thymine for adenine in the beta globin gene, located on chromosome 11), generating Hemoglobin S with a decrease in oxygen binding.
