The correct answer would be
C.) <span>Polio Vaccination.</span>
Answer:
e) Invertebrates lack a nervous system
Explanation:
One of the main characteristics of invertebrates is that they don't have a backbone. Backbones belong to the skeletal system. A totally different story is the nervous system which runs inside the backbone. Although the more complex nervous systems appear in vertebrates the simply fact of having eyes like crabs or insects implies having a nervous system that can control them.
Answer;
C) the amount of time that the two species have been evolving apart
Explanation;
-Scientists can use relaxed-clock methods to deal with variation in the rate of the molecular clock. By measuring the patterns of evolutionary rate variation among organisms, they can also gain valuable insight into the biological processes that determine how quickly the molecular clock ticks.
- The molecular clock hypothesis states that DNA and protein sequences evolve at a rate that is relatively constant over time and among different organisms. A direct consequence of this constancy is that the genetic difference between any two species is proportional to the time since these species last shared a common ancestor.
Answer:
Cyanobacteria
Explanation:
Cyanobacteria were the first photosynthetic autotrophs that used water molecules as the source of electrons. Cyanobacteria were the first autotrophs that performed oxygenic photosynthesis and carried out the splitting of water.
The process of splitting water released oxygen as a gas (O2) which was released in the atmosphere of the earth as a by-product. This led to the accumulation of oxygen in the atmosphere. Some cyanobacteria can fix nitrogen and have specialized cells called heterocyst which serve as the site for nitrogen fixation.
