S Phase it is important that the cell develops properly
Answer:
9:3:3:1
Explanation:
This type of crossing that involves two characters is referred to as dihybrid crossing. Generally, when there is a dihybrid crossing for heterozygous genes for both parents, the phenotypic ratio is usually 9:3:3:1 as shown in the figure in the attached document below.
Assuming the colour is White (P) and Black (p) and the
Height is Tall (T) and short (t)
The possible phenotypes will be in the ration
9 - White and Tall
3 - White and short
3 - Black and Tall
1 - Black and short
It should be noted that phenotypic ratio (phenotype) describes the outward appearance (what can be see physically) and not the genetic make-up. Thus, where there is a dominant character like P or T, the recessive characters are not considered to have been expressed.
The given question is incomplete. The complete question is:
Question: When a neuron responds to a particular neurotransmitter by opening gated ion channels, the neurotransmitter is serving as which part of the signal pathway?
A) relay molecule
B) transducer
C) signal molecule
D) response molecule
Answer:
C) signal molecule
Explanation:
Signaling cells produce specific chemicals or compounds called signaling molecules. These signaling molecules arrive at their target cells and bind to the cell surface or intracellular receptors. Binding of the signaling molecules to their receptors present on the target cells is followed by signal transduction and production of desired response by the target cells.
Neurotransmitters serve as signal molecules that bind to the receptors present on the membranes of the postsynaptic neurons to bring about changes in the membrane potential. Their binding may trigger the opening of the gated ion channels resulting in a change in the membrane potential followed by generation of inhibitory or excitatory responses.
Darwins observations about the fossils support his theory of the tree of life which states we all derive from the same one spark of life. so when he found the fossils in the mountain and it closely resembled animals he had seen on his voyages so this made his hypothesis more believable.
