Answer:
D) found in a limited time span
Explanation:
Index fossils are the remains of living organisms for which we have already established relative age. These are fossils that only existed during a limited period of geologic time and are easily identified, found in large volumes, and found in many different locations around Earth. Due to these factors, index fossils may be used as a guide for comparison in determining the relative age of an unknown object.
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Answer:
D. Sterility Locus
Explanation:
Angiosperms have several mechanisms to prevent self-pollination due to the advantage of cross-pollination. One of such mechanisms is self-incompatibility genes present on the sterility locus.
These genes determine the germination of the pollen on the stigma. If both the pollen and stigma carry the same allele of the gene present at the sterility locus, the germination of pollen is prevented.
The sterility locus has multiple alleles and the presence of the same alleles at the same locus in both pollen and stigma prevents the pollen germination.
For example, pollen from S1S2 individuals can not germinate on the stigma with the S1S3 genotype. Here, the pollen does not obtain water as required for germination from the stigma and are unable to germinate.
Answer: false
Explanation: it means they run together
Since the formation of the San Andreas Fault system 25-30 million years ago, the juxtaposition of the Pacific and North American plates has formed many faults in California that accommodate lateral motion between the plates.
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