The prefix “hydro-“ relates to water
Answer:
cnidarians
Explanation:
Cnidarian is a phylum of organisms that comprises of the simplest forms of multicellular organisms. Examples of cnidarians includes; coral animals, jellyfish, and sea anemones among others.
They are soft-bodied, carnivorous animals that have stinging tentacles arranged in circles around their mouths. They are the simplest animals to have body symmetry and specialized tissue.
All cnidarians are aquatic, mostly marine organisms, and have two body layers that is the ectoderm and endoderm.
It must be widespread, limited in geological time, and distinctive.
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They have their tentacles which house cells called<span> cnidocytes.</span>
Answer:
D. Population genetics
Population genetics is the study of genetic variation within populations, and involves the examination and modelling of changes in the frequencies of genes and alleles in populations over space and time. ... In natural populations, however, the genetic composition of a population's gene pool may change over time.
Explanation:
microevolution - evolutionary change within a species or small group of organisms, especially over a short period. (Not studying the overall evolution in the population, just a single allele usually) Not it then
macroevolution - Macroevolution in the modern sense is evolution that is guided by selection among interspecific variation, as opposed to selection among intraspecific variation in microevolution (this goes over huge groups of different species) Not it then
gene pool - The gene pool is the set of all genes, or genetic information, in any population, usually of a particular species. (Not the study of evolution in a population) Not that then
So it has to be D