Amoeba are the consumers that surround, engulf, and ingest their food.
<h3><u>Explanation</u>:</h3>
Amoeba is a unicellular organism that belongs to the kingdom Protista. This organism are having eukaryotic cells without any cell walls. These organisms have each and every cellular organelle that are needed to perform metabolism.
Amoeba are consumer in mode of nutrition. Whenever they senses some food, they push a part of their cytoplasm packed in cell membrane towards the food to cover it. This process is called pseupodia.
This pseupodia engulfs the food and performs phagocytosis or pinocytosis. This food is covered in a cell membrane inside the cytoplasm which is called the food vacoule or endosome. This then fuses with a lysosome to digest and then the excretory product is let off by the secondary vacoule.
Answer:
False
Explanation:
The histones that are more positively charged, tight hardly to negatively charged DNA. So, enzymes, such as acetyltransferases, that reduce the positive charge of histones promote transcription.
Chromatin structure and its modifications can change the package of the DNA and consequently, alter the gene expression. The most common modifications of the chromatin are covalent modifications such as acetylation/deacetylation (by acetyltransferases and eacetylases), methylation (by methyltransferases), and phosphorylation (by kinases). This is the way of gene expression regulation.
The effects of modifications are different, for example methylation promotes condensation of the chromatin and as a consequence, prevents binding of transcription factors to the DNA (transcription is repressed).
Acetylation loosens the association between nucleosomes and DNA (because it neutralizes the positive charge of histones) and consequently promotes transcription. Deacetylation is a process opposite to acetylation.
A eukaryotic cell has a nucleus as well as membrane bound organelles such as the golgi apparatus, endoplasmic reticulum ect.
I think A makes the most sense..
