Answer:
The chemical basis of Chargaff"s rule is the bonding properties of the DNA bases.
Explanation:
According to the Chargaff"s rule in a DNA molecule the total number of purine bases are equal with the total number of pyrimidine bases that means
Adenine +Guanine=Thymine +Cytosine
In simple words the rule is based on the 1:1 ratio of both purine and pyrimidine bases.
Answer:
The addition and response to the net effect of postsynaptic potentials is called Spatial summation
Explanation:
Signal summation occurs when impulses received by a neuron are eummed together to reach the excitation threshold to fire a neuron. It occurs at the axon hillock of a neuron. Signal summation occurs since each neuron is connected to many other neurons, often receiving multiple impulses from them, both excitatory and inhibitory.
Signal summation can either be temporal or spatial.
Temporal summation, occurs when impulses received at the same place on the neuron in close temporal succession add up to initiate an action potential in the neuron.
Spatial summation occurs when impulses received simultaneously at different places on the neuron add up to initiate an action potential in the neuron.
A phylogeny is an evolutionary ”tree” of related
organisms that can be constructed by using
information obtained from the genetic material.
Genetic information is contained in all living cells,
in the form of long DNA molecules that take the
shape of connected double- stranded spirals
(DNA stands for deoxyribonucleic acid). DNA
spirals, or “helixes”, are tightly compressed in the
nucleus of every cell. Their information is
organized into a code made up of four small
molecules — the building blocks of DNA. The
molecules, called nucleotides, are labelled:
A (adenine), C (cytosine), G (guanine) and T
(thymine).
It is possible to draw conclusions about the
evolution of a group of plant or animal species,
and the relationships among them, by comparing
selected pieces of DNA.
