Answer:
True
Explanation:
Mitosis results in two cells that are genetically identical. DNA replication only occurs during "S phase." Meiosis is commonly defined as a type of cell division that divides a somatic cell and produces four gamete cells when doing so.
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<u><em>S phase:</em></u> In S phase, the cell synthesizes a complete copy of the DNA in its nucleus. It also duplicates a microtubule-organizing structure called the centrosome. The centrosomes help separate DNA during M phase.
<u><em>Gametes</em></u> are an organism's reproductive cells. They are also referred to as sex cells. Female gametes are called ova or egg cells, and male gametes are called sperm. Gametes are haploid cells, and each cell carries only one copy of each chromosome.
Rodent like teeth, leg structure, better eyes
Directional selection acts against b<span>oth extremes simultaneously in the variation of the trait. This is the most "aggressive" form of selection and only happens in extreme areas.
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Answer:
Please find the explanation below
Explanation:
Our nucleus is made up of a genetic material called deoxyribonucleic acid (DNA), which is a double-helical structure that stores the genetic information needed for the optimal functioning of any organism. DNA, alongside RNA are nucleic acids that are composed of NUCLEOTIDES subunits. The nucleotide consists of a pentose sugar (deoxyribose in DNA and ribose in RNA), nitrogenous base and a phosphate group.
However, the genetic information stored in the DNA molecule needs to be expressed in order to form useful products (proteins). This genetic expression is done in two stages viz: transcription and translation. Transcription, which is catalyzed by an enzyme called RNA polymerase is the process whereby the information stored in the DNA is used to synthesize a mRNA molecule. However, this mRNA molecule is considered pre-mature until it is processed. RNA processing occurs in three stages viz: 5' capping, polyadenylation, and splicing.
5' capping involves adding a 5' cap to the marks molecule. Polyadenylation involves adding a poly(A) tail to the mRNA molecule while splicing is the removal of introns (non coding regions) with the aid of Spliceosomes and joining of the exons (coding region). After processing, the mRNA becomes matured and ready to be translated.
Translation is the process whereby the mRNA transcript is used to synthesize a protein molecule. It occurs in the ribosomes (organelles for protein synthesis, a complex of rRNA and proteins) where the mRNA is read in a group of three nucleotides called CODON. The reading is done by the Anticodon of a transfer RNA (tRNA), which is complementary to the codon.
Translation occurs in three stages: initiation, elongation and termination. The mRNA attaches to the P site of the ribosomes (initiation) where it is attached to by a tRNA's anticodon complementary to it. The anticodon carries the amino acid corresponding the codon and shifts to the A-site. The addition of amino acid to the polypeptide chain continues (elongation) until a stop codon is encountered, which signals the end of the translation process i.e. termination. This causes the polypeptide (protein) to be released from the E-site.
The synthesized protein undergoes packaging and modification in the Golgi apparatus.
