Earthworms have two muscles which is used in locomotion. Both muscles are circular and longitudinal (inner layer of the series of muscles). The diameter of the earthworms body is reduced when the circular muscles are contracted which makes them appear to be thin. The worm appears short when the longitudinal muscles contract thus, its length is reduced.
Amphioxus on the other hand, have two unique muscle fiber types. This includes deep fibers and smaller but mitochondria-rich superficial fibers. E<span>ach of which has its own innervation.</span>
The correct answers are:
- Methylation of histone tails in chromatin can promote condensation of the chromatin.
- DNA is not transcribed when chromatin is packaged tightly in a condensed form.
- Acetylation of histone tails is a reversible process.
- Some forms of chromatin modification can be passed on to future generations of cells.
- Acetylation of histone tails in chromatin allows access to DNA for transcription.
Histone modifications are post-translational modifications of histone protein that can affect gene expression by altering chromatin structure or recruiting histone modifiers.The most common modifications are methylation, phosphorylation, acetylation and ubiquitylation. All of them affect the binding affinity between histones and DNA and thus loosening (gene activation) or tightening (gene repression) the condensed DNA.
Histone methylation is a transfer of methyl group by histone methyltransferases to lysine or arginine amino acid of protein. Effect of methylation depends on the type of protein that is modified. Demethylation is the reverse process.
Histone acetylation is the process of adding of an acetyl group(by histone acetyltransferases) to histone proteins and it can also activate or inhibit the gene expression. Deacetilation is reverse process.
Answer:
The diagram can be improved by:
Lungs
↓
oxygen
↓
Red blood cells (carrying oxygen)
↓
Organs (like stomach and liver etc) from where carbon
is taken and oxygen is supplied
↓
RBC's carrying Carbon dioxide to the lungs
The component which is missing in the diagram are the organs where exchange of gases occurs. The red blood cells carry oxygenated blood from the lungs to all parts of the body and carries the wast carbon dioxide gas from them back to the lungs. The carbon dioxide is then exhaled by the lungs.
Answer:
cvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvExplanation:
Answer:
A. Orogenic
Explanation:
orogeny tends to occur during a relatively short time in linear belts and results in intensive deformation.
