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.
Embryonic development involves process of formation and development of an embryo. In humans, during the early stages, 10 weeks of embryonic development, all the major body organs are formed.
The common characteristic of those two organisms is hard spherical shells (exoskeleton).
Foraminiferans are single cell marine eukaryotes divided into granular endoplasm and transparent ectoplasm. Foraminiferans are enveloped with tests, hard shells, usually composed of calcium carbonate (sometimes from organic compounds or silica).
Coccolithophore is a unicellular, eukaryotic alga with special calcium carbonate plates (or scales) of uncertain function (coccoliths). Each unicellular alga is enclosed in its own collection of coccoliths, the which make up its exoskeleton- coccosphere.
A, because it the constant variable
The DNA molecule is packaged into thread-like structures called chromosomes. Each chromosome is made up of DNA tightly coiled many times around proteins called histones
