The oldest fossils present at the bottom of rock layer whereas the youngest fossils are present in the top layer.
<h2>Rock layers from oldest to youngest</h2>
The rock layers that is located farthest from the ground surface are considered as the oldest rock layers and rock layers that are closest to the ground surface are considered as the youngest. A fossil is the remains or traces of plants and animals that lived long ago.
<h3>Presence of fossil</h3>
Those fossils which are present at the bottom of the rock layers are considered as the oldest fossil followed by the upper layer's fossil and so on. The fossils present at the top layer are the youngest fossils so we can conclude that oldest fossils present at the bottom of rock layer whereas the youngest fossils are present in the top layer.
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The substance that is coded for by a length of DNA is base. The correct option is A.
<h3>What is a base?</h3>
Nucleobases, also known as nitrogenous bases or simply bases, are nitrogen-containing biological compounds that form nucleosides, which are then components of nucleotides, all of which are the basic building blocks of nucleic acids.
The complete question is attached.
The substance that is coded for by a length of DNA is base.
Thus, the correct option is A.
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A circuit is the path that an electric current travels on, and a simple circuit contains three components necessary to have a functioning electric circuit, namely, a source of voltage, a conductive path, and a resistor.
The answer is organism.
Reason why:
A species is an environment of related organisms. A community is a population of common goals. A population is a headcount of how many animals there are of one animal kind.
Answer:
Genetic variation occurs because beneficial traits exist in a collection of genes, and gene flow makes these traits more prevalent in populations.
Further explanation
Genetic diversity is a level of biodiversity that refers to the total amount of genetic variation in the whole species that inhabits some or all of the earth's surface that can be inhabited.
Genetic diversity uses several simple measurements:
Gene diversity is the proportion of polymorphic loci throughout the genome.
Heterozygosity is the average number of individuals with polymorphic loci.
Alleles per locus, also used to demonstrate variability.
