Answer:
Every fossil tells us something about the age of the rock it's found in, and index fossils are the ones that tell us the most. Index fossils (also called key fossils or type fossils) are those that are used to define periods of geologic time
Explanation:
D. Secondary online and layers of periderm
Answer:
A protein-coding gene has an open reading frame (ORF) that make easier its identification
Explanation:
During translation, the messenger RNA (mRNA) is read by the ribosomes as triplets of nucleotides called codons in the open reading frame (ORF). An ORF can be defined as a gene fragment composed of codons which are translated into amino acids in a polypeptide chain. According to the genetic code, the information encoded by these codons will specify the sequence of amino acids in the protein, as well as the start codon and stop codons of the protein-coding genes. A start codon (AUG) is a site at which translation into protein begins, while stop codons (UAA, UAG, and UGA) mark the site at which translation ends. Moreover, non-coding RNAs (ncRNAs) don't have ORFs because they do not encode for proteins, and therefore their identification is more difficult.
They move waste and nutrients through the intestines.
Answer:
A. Chelicerates are a group of arthropods
E. Sea urchins are a group of echinoderms
B. Gastropods are a group of mollusks
Explanation:
Chelicerates are primitive arthropods having 6 pairs of appendages. 1 oral appendage used for feeding and lack actual mouth parts for chewing up "suck up predigested food". Cephalothorax is the largest and Abdomen contains gills.
Sea urchins are a group of echinoderms as they have spin skin , all marine and found in the bottom of the sea.
Gastropods are the largest and most varied group of molluscs. Gastropod means stomach footed, a typical gastropod is a coiled mass of organs enclosed in a dorsal shell, which rests on the foot having a head ans sensory structures on head and having an operculum.
