An endangered species is a type of species in which this type of organism has decreasing numbers and are dangerously close to going extinct. Invasive species are species in which an organism invades an environment where it is not native to, and take over the ecosystem. Local species are species in which the organism is native to that environment and plays a key role in that ecosystem. A keystone species is a species in which the organism is a key part of that ecosystem to thrive; without it, the ecosystem would collapse
Destruction of coral reefs would cause an imbalance in the ecosystem. Some species could be driven to extinction.
Coral reefs are the base of the most diverse marine ecosystem in the world. They are often referred to as the ‘rainforest’ of the oceans and seas. They provide shelter for cnidarians, sponges, crustaceans, and etcetera and provide hiding grounds from predators.
Insulin is produced by beta cells of the pancreas for storing and disposing of the glucose in various parts of the body like liver. This activity is a differentiated function of the beta cells of pancreas only. Although gene for insulin production is present in all cells, it is expressed only in the beta cells. Hence, it is a differentiated function.
Microorganisms can be divided into two groups:
1. Archea
• Archea are prokaryotic unicellular organisms without cell nucleus or other membrane bound-organelles.
• Their membrane is built from ether lipids, which differs them from bacteria’s cell membrane.
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2. Bacteria
• Bacteria are also unicellular prokaryotic organisms.
• Bacterial cell membranes are made from phosphoglycerides with ester bonds. Bacterial genome is in a form of circular chromosome.
• They reproduce by binary fission or by budding.
Besides, prokaryotes (Archea and Bacteria) a large number of eukaryotes are also microorganisms. Unicellular eukaryotes contain organelles such as the cell nucleus, the Golgi apparatus and mitochondria. Usually, they reproduce asexually by mitosis. An example of eukaryotic microorganism is Protist.
Answer:
A = Activator
B = Effector
Explanation:
An activator is a protein which typically binds to a short (50–1500 bp) region of DNA which might be located either upstream (mainly) or downstream of a gene so as to cause increased transcription. This particular region of DNA is known as enhancer and activator is also known as transcription factor. Activator is a trans-acting factor which binds to the cis-acting factor which is enhancer so as to enhance transcriptional expression.
But another protein named as effector may restrict activator from binding to the enhancer leading to a decrease in transcriptional expression by binding to the activator allosterically. Allosteric binding of effector to the activator causes conformational change in activator so it can no longer bind the enhancer.
