Answer:
If twins are a boy and a girl, clearly they are fraternal twins, as they do not have the same DNA. A boy has XY chromosomes and a girl has XX chromosomes. Girl-boy twins occur when one X egg is fertilized with an X sperm, and a Y sperm fertilizes the other X egg.
Explanation:
Answer:
Cerebrospinal fluid circulates within the ventricles of the brain and in the subarachnoid space is called Cerebrospinal fluid circulation
Explanation:
CSF is formed within the ventricles by small, delicate tufts of specialized tissue called the choroid plexus
the major pathway of CSF flow. Beginning in the lateral ventricles, CSF flows through two passageways into the third ventricle. From the third ventricle it flows down a long, narrow passageway (the aqueduct of Sylvius) into the fourth ventricle. From the fourth ventricle it passes through three small openings (foramina) into the subarachnoid space surrounding the brain and spinal cord
Answer:
Each three base sequence of the mRNA, called a codon, is read by the ribosome, and the appropriate amino acid is inserted into the growing protein. If you have only a DNA sequence, to find the corresponding amino acids first transcribe your DNA sequence into an RNA sequence using complimentary base pairing.
Explanation:
Convergent A subduction zone is formed at a convergent plate boundary when one or both of the tectonic plates is composed of oceanic crust. The denser plate, made of oceanic crust, is subducted underneath the less dense plate, which can be either continental or oceanic crust.