APIBS Biology Classes

A synovial joint, also known as diarthrosis, joins bones with a fibrous joint capsule that is continuous with the periosteum of the joined bones, constitutes the outer boundary of a synovial cavity, and surrounds the bones' articulating surfaces. The synovial cavity/joint is filled with synovial fluid.

ERYTHROBLASTOSIS FETALIS
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Erythroblastosis fetalis is hemolytic anemia in the fetus (or neonate, as erythroblastosis neonatorum) caused by transplacental transmission of maternal antibodies to fetal RBCs. The disorder usually results from incompatibility between maternal and fetal blood groups, often Rh0(D) antigens. Diagnosis begins with prenatal maternal antigenic and antibody screening and may require paternal screening, serial measurement of maternal antibody titers, and fetal testing. Treatment may involve intrauterine fetal transfusion or neonatal exchange transfusion. Prevention is Rh0(D) immune globulin injection for women who are Rh-negative.

During cell division, sometimes there will be failure of separation of sister chromatids. This event is called
a) interference
b) coincidence
c) fusion
d) Non disjunction

DO YOU KNOW?
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The average human produces 25,000 quarts of saliva in a lifetime, enough to fill two swimming pools.

During synapsis the number of thread (Chromonemata) in each chromosome is
a) 2
b) 4
c) 8
d) Many

DO YOU KNOW ????
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Like Wolverine, the liver is the only organ that can completely regenerate. As little as 25% of the original liver mass can regenerate back to its full size.

The water potential of pure water at atmospheric pressure is
a) -2.3 bar
b) +2.3 bar
c) Zero bar
d) One bar

TENTATIVE SCHEDULE FOR ONLINE COUNSELING FOR NEET -2018 (15% AIQ)
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THE STEPS OF PCR
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The key ingredients of a PCR reaction are Taq polymerase, primers, template DNA, and nucleotides (DNA building blocks). The ingredients are assembled in a tube, along with cofactors needed by the enzyme, and are put through repeated cycles of heating and cooling that allow DNA to be synthesized.

The basic steps are:
Denaturation (96°C):
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Heat the reaction strongly to separate, or denature, the DNA strands. This provides single-stranded template for the next step.

Annealing (55 - 65°C):
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Cool the reaction so the primers can bind to their complementary sequences on the single-stranded template DNA.

Extension (72°C):
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Raise the reaction temperatures so Taq polymerase extends the primers, synthesizing new strands of DNA.

This cycle repeats 25- 35 times in a typical PCR reaction, which generally takes 22 - 44 hours, depending on the length of the DNA region being copied. If the reaction is efficient (works well), the target region can go from just one or a few copies to billions.

That’s because it’s not just the original DNA that’s used as a template each time. Instead, the new DNA that’s made in one round can serve as a template in the next round of DNA synthesis. There are many copies of the primers and many molecules of Taq polymerase floating around in the reaction, so the number of DNA molecules can roughly double in each round of cycling.

DO YOU KNOW ???
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The human brain only makes up 2% of a person’s body weight, but needs 20% of the body’s oxygen and 15% of the heart’s work.