Answer:a) a sturdy-finned, shallow-water lobe-fin whose appendages had skeletal supports similar to those of terrestrial vertebrates.
Explanation:
An ancestor - An earlier type of a species at any distant time — a progenitor.
A tetrapod is any vertebrate with four limbs. It includes any vertebrate (such as birds or snakes) that have evolved from early tetrapods — especially all members of the superclass Tetrapoda.
The presence of bones that support the appendages in Lobe – fin fish were found to be similar to the categorical skeletal supports found in the limbs of sample tetrapods. The sub class crossopterygii includes the Lobe – fin fish, which is seen as one of the recent common ancestor of living tetrapod today.
If you go on mc3.edu/admissions/applying-to-mccc/testing-and-assessment/assets/biology-placement-test.pdf page 11 it will tell you all the answers to your questions....
A. The hosts body could reject the transplanted stem cells
mRNA
Messenger RNA is used to copy and encode genetic information from DNA base pairs by forming complementary strand of RNA molecule from the nucleus of the cell to the cytoplasm.
tRNA
Transfer RNA reads sequence of nucleotide from messenger RNA and translate them into proteins or amino acids during proten synthesis.
Transcription
This is the first step in gene expression where information from DNA is copied into a complementary strand of RNA molecule using RNA polymerase enzyme.
Translation
Messenger RNA made from the process of transcription travels to the ribosomes in the cytoplasm where proteins are produced using transfer RNA to copy the information.
The use of DNA to make proteins.
Through gene expression (central dogma of biology), the DNA molecule carries information, a gene code, in form of base pairing sequences that are transcribed to RNA and further translated to functional proteins or amino acids.