Answer:
neurotransmitter is a chemical messenger that carries, boosts, and balances signals between neurons (also known as nerve cells) and target cells throughout the body.
The terminal cisternae releases calcium ion
The terminal cisternae act as calcium storage sites. The calcium ions stored in the terminal cisternae are essential in muscle contraction. The calcium release unit of muscle consists of terminal cisternae of the sarcoplasmic reticulum and it is adjacent transverse or T- tubule that is the invaginated part of the surface membrane.
Answer :
The animals are categorized into 2 groups - eukaryotes and prokaryotes. The microbes like bacteria are coming under prokaryotes. They are unicellular organisms and without a true nucleus.
Viruses are the connecting link between the living and non - living. They are smaller than bacteria. The microbes less than 100 micrometer can't be seen by the naked eye. They can only visible under a microscope.
Viruses like polio, flu virus sizes are 10nm. But some of the viruses are also less than 10nm. The size of bacteria is 1 micrometer. The viruses are 10 times smaller than the bacteria.
The eukaryotic organisms are more advanced and multicellular. Their cell size is larger than bacteria and viruses. The red blood cells under the light microscope are 8 micrometers. The typical animal cells like sperm are 60 micrometers and a skin cell is 30 micrometers. The plant cell for example pollen is 90 micrometers.
The eukaryotic cells sizes are more than prokaryotes like bacteria.
Answer:
c. ¼ heavy, ¾ light
Explanation:
DNA replication follows semi conservative model which means that both the strands separate during replication and the newly formed DNA molecule has one old and one new strand. If instead of semi conservative, conservative mechanism is used, old strands will not separate from each other and the two newly synthesised DNA strands will come together to form a DNA molecule.
Here the cells were first grown in heavy 15N medium so all the DNA molecules had 15N and thus were heavy. Then the cells were transferred to 14N medium where only lighter 14N were available for replication process.
In first generation, 14N DNA molecules were synthesised from 15N DNA molecules so 1/2 DNA molecules were 15N and other half were 14N. In the second generation, 14N molecules will give rise to new 14N molecules and 15N molecules will also give rise to 14N molecules hence 1/4 molecules will be 15N (heavy) and 3/4 will be 14N (light).
