Answer:
A. Competition
Explanation:
Both species of bird need to compete for limited resources, in this case they need to compete for both territory and food
Answer:
True
Explanation:
Because thyroide gland's secretion thyroxin regulates immune system in our body
Cycles related to earths movement. they are now called milankovitch in his honor
She has the greatest chances of conceiving about halfway through her menstrual cycle, or at the 14 day mark.
<h2>Gene regulation </h2>
Explanation:
Transcriptional gene regulation:
- Eukaryotic gene expression is mainly regulated at transcription level
- In eukaryotic transcription initiation of a gene require change in chromatin structure(chromatin remodelling) because promoter and other regulatory elements of DNA exposed after removal of histone core
- Chromatin remodelling can be induced by two separate mechanism;
- By histone modification:includes acetylation,methylation and phosphorylation
- Histone acetylation catalysed by histone acetyl transferase(HAT) and favours gene expression
- Histone deacetylation is catalysed by histone deacetylated enzyme(HDACs) and is always associated with gene repression
Post transcriptional gene regulation:
- Splicing is the modification event of pre mRNA which occurs in nucleus just after transcription but before the RNA moves to the cytoplasm
- In RNA splicing non coding regions of pre mRNA called introns are removed and coding regions called exons are religated
- Removal of every intron requires two transesterification reactions:
- First transesterification reaction displaces exon from intron with 3' OH group
- Second transesterification reaction always catalysed by 3'OH group of displaced exon at 3' splice site
Translational gene regulation:
- Eukaryotic translation is required for preparation of ribosomal small subunit which in turn require large number of initiation factors
- eIF2 facilitate transportation of initiating tRNA from cytosol to the P site of ribosomes
- eIF2α serves as key regulatory role in global protein synthesis and inhibits protein synthesis in response of cellular stress
Post translational gene regulation:
- Post translational modifications includes phosphorylation or occurs by means of irreversible events (proteolysis)
- Post translational modifications play a fundamental role in regulating the folding of proteins, their targeting to specific subcellular compartments, their interaction with ligands or other proteins, and their functional state, such as catalytic activity in the case of enzymes or the signaling function of proteins involved in signal transduction pathways
- Phosphate moiety is covalently bound to an amino acid, phosphorylation occurs through the action of specific protein modifiers called kinases
