In biology, the inner lining of tubular structures is called a lumen.
This can refer to numerous tubular structures in the body, such as the lumen of the veins and arteries, the lumen of the intestines or the tubes in the kidneys.
This term can also be used to describe a space defined by membranes of cell organelles such as the lumen of the mitochondria, the Golgi apparatus, and others.
Answer:
Explanation:
A boundary that distinguishes inside from outside the cell yet allows materials to enter or leave the cell.
The cell needs a barrier for protection, rigidity and also for easy transportation.
<span>The three groups of amphibians: Frogs, Salamanders, Caecilians are different when they reach adulthood. Frogs have four legs with strong hind legs and no tails. Salamanders have tails and four short, weak legs that cause them to walk instead of jump. Lastly, Cacilians have no legs and are burrowing animals.
Amphibians must live in moist environments because they loose water through their thin skin. They need to be near water to replenish the lost water. Also their skin helps them breathe and they can get oxygen from the water.</span>
Yes accumulation of mutation can drive aging process.
Explanation:
The molecular damage that occurs in cells and tissues for a long time due to DNA damage and epigenetic changes gets accumulated in the cell.
This leads to lowering of the homeostasis in the cell during stress conditions and eventually risks of life-threatening diseases as cancers or neurodegenerative disorders develop.
Due to mutation in the gene DNA repair mechanism also gets affected this also contributes to the ageing of cells.
The telomere of the chromosome is shortened after every mitotic division but telomerase enzyme keeps adding the DNA sequence preventing shortening aging and death of the cell. If the mutation occurs in this enzyme it will increase the ageing of cells at high rate.
Answer:
The correct answer would be 2,70,000 nucleotide long gene.
The gene refers to the protein coding sequence of the (deoxyribonucleic acid) DNA.
The nucleotide sequence of a gene corresponds to the codon sequence if mRNA. The codon sequence of mRNA then codes for the amino acid sequence of the protein.
The codon refers to the set of three nucleotide which codes for a specific amino acid. For example, CAG codes for glutamine, AUG codes for methionine et cetera.
So, if the polypeptide chain consists of 90,000 amino acids then it must contain 90,000 x 3 nucleotides which are equal to 2,70,000 nucleotides.
