Darwin's proposed mechanism for evolution is natural selection. Natural selection allows species to respond to their surroundings through time, or to become progressively excellently-suited. Natural selection is environmentally based and involves established heritable variation within a population.
They lead to changes in species over time:
- Darwin suggested species will evolve over time, new species originate from pre-existing species, and all species share a common ancestor with each other.
- In this framework each organism has its own special set of heritable i.e genetic variations from the common ancestor that have slowly developed over very longer periods of time.
- Parroted branching activities that isolate new species from a common ancestor create a multi-level tree that connects all living organisms.
<span>When cells were first taken from Henrietta Lacks, she was suffering from cervix cancer. Henrietta Lacks was a woman whose cervix cancer cells were used as the source of the HeLa cell line nowadays used in medical research. During treatment for cervical cancer in 1951, the cells were taken without her knowledge. The cells were cultured by George Otto Gey who created the HeLa cell line.</span>
<u>Answer:</u> "Chemical fossils"evidence supports the notion that sponges are some of the earliest known multicellular animals.
<u>Explanation:</u>
Sponges are multicellular animals, may belong to Ediacarian period likely to be 80 million years ago or earlier. They catered through a complex system of internal channels, by moving seawater.
Sponges are soft-bodied and very rarely protected as fossils, therefore finding evidence of existence is giant task. The key of their existence came to know from abnormal chemicals which is a steroids of a particular type generated sufficiently by them but virtually never by ordinary organisms.
Analysis of long strata sequence found in Oman and researchers have been able to extract these "chemical fossils" from samples spanning tens of millions of years — before, during and after the Ediacarian period.This gave clear evidence that sponges had to have evolved long before the great variety of multicellular organisms proliferated at the dawn of that time.
Answer: The correct answer is- all the sugar maple trees that are present in a state park.
Population can be described as a group of individuals belonging to a particular species, which inhabit a particular area.
In this question, last option that is all the sugar maple trees that are present in a state park correspond to a particular population.
Other options have organisms occupying different areas across the world.
Diploblasty is a state of the blastula in which there are two essential germ layers: the ectoderm and endoderm. Diploblastic living beings are life forms which create from such a blastula and incorporate cnidaria and Ctenophora, earlier assembled together in the phylum Coelenterata, yet later comprehension of their disparities brought about their being put in discrete phyla.
To answer the above:
Diploblastic animals have ectoderm and an endoderm as well as radial symmetry.
