Answer:
A, C, D are true, B is false
Explanation:
Prokaryotic cells are surrounded by a plasma membrane, but they have no internal membrane-bound organelles within their cytoplasm. They have a cell wall and cytoplasm containing ribosomes
Answer:
Phytoplankton production is necessary to begin a food web in an ocean ecosystem.
Explanation: Hope it helps you :)))))))
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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:
Organelles
Explanation:
Bacteria are a type of biological cell that has an Intracellular or internal structure.
Structural components are located in bacteria, and we can find there DNA, ribosomes, cell wall and membrane, surface layer and cytoplasm.
In bacteria structural components aren't found '<u>The nucleus</u>' and that is a membrane-enclosed organelle.
Answer:
flagella
Explanation:
Some bacteria have tail-like structures called flagella
