Answer:
A group of parasites called myxozoans have traditionally been considered simple multicellular protists. However, because these organisms possess stinging cells, some scientists consider them to be animals in the phylum that is named for such cells, the <u>cnidarians</u>.
Explanation:
Cnidarians are animals with radial symmetry, that is, their bodies can be divided, by different planes, into equal parts. It includes hydras, jellyfish, anemones and marine corals. Its body is a kind of sac with an opening (the mouth) surrounded by a circle of tentacles. Some have a dominant jellyfish phase, others polyp, or both. They present defensive nematocysts with stinging action.
Answer:
Pheromones
Explanation:
Pheromones play an important role in the behavioral isolation of insect species. These compounds serve to identify individuals of the same species and of the same or different sex. Evaporated molecules of volatile pheromones can serve as a wide-reaching chemical signal. In other cases, pheromones may be detected only at a short distance or by contact.
Asexual reproduction produces genetically identical offspring and sexual reproduction creates variation in the offspring. When the environment changes and it affects the asexual offspring it will affect all identical copies whereas since the sexual offspring have more variation, they are more likely to survive.
<span>The memory test that would most effectively reveal that mr. marchman, at age 65, still remembers many of his high school classmates, is RECOGNITION test. </span>Recognition memory <span>is the ability to recognize previously encountered events, objects, or people.</span>
Answer:
a. a portion of the population becomes isolated from the remainder of the population and experiences different selective pressures
Explanation:
This is an example of allopatric speciation Allopatric speciation is a form of speciation (formation of new species) that occurs as a result of geographic isolation. This means that a part of population becomes physically separated from the initial main population. There is no gene flow between these two populations and as a result the two populations reach a high level of genetic divergence. They can no longer interbreed which means they become two different species (speciation).
New populations evolve as result of mutation, genetic drift and natural selection.
For example, Galapagos finches are isolated from others by the ocean (geographic isolation). Because of the isolation, the finches don’t breed with one another. So, they developed unique characteristics and became endemic.
