D. nRNA... hope it helps :)
Answer:
Watson and Crick proposed the double helical model of DNA.
Explanation:
- This model says that DNA exist as double helix. It has two polynucelotide strands running in opposite direction i.e the strands are anti-parallel.
- Each polynucleotide strand is made up of several nucleotide liknked together by phophodiester bonds.
- The two strands are not coiled upon each other but the double strand is coiled upon itself around a common axis like the spiral stair case. Here base pairs forms the stairs and backbone of two strands form railing. Back bone contains sugar and phosphate.
- The base pairing is specific, adenine always pairs with thymine and guanine always pairs with cytosine. Thus if we see any base pair, it consists of one purine and one pyrimidine.
- The two strands of DNA thus show complementary base pairing.
- The strands are held together because of hydrogen bonding between the bases in opposite strand.
- One full helical turn involves ten base pairs and the base pairs are stacked 3.4 A apart.
- This form is called as B-form of DNA.
Answer:
Cell theory refers to the idea that cells are the basic unit of structure in every living thing. Development of this theory during the mid 17th century was made possible by advances in microscopy. This theory is one of the foundations of biology.
Answer:
They difference in phenotypes is dependent on the genes. The more dominant gene will overpower a recessive gene, or if there are two recessive genes together, that will be the phenotype. When things are cross breaded they introduce different genotypes that allow for different looking phenotypes.
Example: Dominant blue flower (Bb) mixed with recessive yellow flower (bb)
B b
b Bb bb
b Bb bb
There is a 50/50 chance the offspring will be either blue or yellow
El sistema inmune innato se compone principalmente de barreras físicas, como la piel y las membranas mucosas, barreras químicas, a través de la acción de péptidos antimicrobianos y especies reactivas de oxígeno [4], células inmunes innatas y mediadores solubles como el sistema del complemento, anticuerpos innatos
Explanation:
