3.8 billion – 2.5 billion years ago
The Archean is the name of the age which started with the shaping Earth. This time of Earth's history endured quite a while, over 2.5 billion years. When the archean age ended the earth was just coming alive.
I do not know the answer to this question
Long-term potentiation (LTP) is considered a cellular correlate of learning and memory. The presence of G protein-activated inwardly rectifying K(+) (GIRK) channels near excitatory synapses on dendritic spines suggests their possible involvement in synaptic plasticity. However, whether activity-dependent regulation of channels affects excitatory synaptic plasticity is unknown. In a companion article we have reported activity-dependent regulation of GIRK channel density in cultured hippocampal neurons that requires activity oF receptors (NMDAR) and protein phosphatase-1 (PP1) and takes place within 15 min. In this study, we performed whole-cell recordings of cultured hippocampal neurons and found that NMDAR activation increases basal GIRK current and GIRK channel activation mediated by adenosine A(1) receptors, but not GABA(B) receptors. Given the similar involvement of NMDARs, adenosine receptors, and PP1 in depotentiation of LTP caused by low-frequency stimulation that immediately follows LTP-inducing high-frequency stimulation, we wondered whether NMDAR-induced increase in GIRK channel surface density and current may contribute to the molecular mechanisms underlying this specific depotentiation. Remarkably, GIRK2 null mutation or GIRK channel blockade abolishes depotentiation of LTP, demonstrating that GIRK channels are critical for depotentiation, one form of excitatory synaptic plasticity.
Learn more about receptors here:
brainly.com/question/11985070
#SPJ4
Answer:
All of the above are true
Explanation:
Organisms possess two types of genome viz; prokaryotic genome and eukaryotic genome. The eukaryotic genome is possessed by cells with a well-defined nucleus, where their genetic material (DNA). The prokaryotic genome, on the other hand, lacks a membrane-bound nucleus. The major organization or content between these two genomes are:
- Prokaryotic genomes generally have less DNA and fewer genes than eukaryotic genomes.
- Prokaryotic genomes have fewer repeated sequences and noncoding, intragenic sequences than eukaryotic genomes.
- Most prokaryotic genomes are contained in one circular chromosome while most eukaryotic genomes are contained on several linear chromosomes.
- In general, eukaryotic genomes contain many introns, repeated sequences, and transposable elements.
Based on this, all of the above options are TRUE
