Answer: Autocrine signal, paracrine signal and endocrine signal.
Explanation:
Testosterone is an example of hormone which shows its effect on different locations of the cells.
The autocrine signal can be defined as the siganals which shows its effect on the cell from where it is being produced. This means a cell targets itself.
Then comes the paracrine signals in which signals acts locally on the cells nearby it. The cells close together to the cells producing chemical signals is being affected.
The endocrine signals can be defined as the effect of the hormone on the distant cells. The signals is produced by the cells somewhere else but is carried through the bloodstream to the distant cells.
All of the three effects is being shown by testosterone autocrine, endocrine and paracrine.
In the scientific method first of all is you need to identify the problem, the problem to your question is why does the dog circle its bed before lying down. Second is the observation to gather some data, you need to observe the dog if what could be the possibility the the dog may do that action. The third is the pre hypothesis, you need to came up with an idea why does the dog do such and action for example the needs to find a correct spot to make itself comfortable and lastly the hypothesis, this should answer to your question or your problem. So my hypothesis is that dogs are one of the animals that are those difficult to find a place to sleep and some of that kind of animals are cat, before they lay on their bed, they have to circle to find a spot that could fit its body to be more comfortable when the dog sleep
Answer:Eukaryotes only (A) and (D), bacteria only (E) both (B) and (C).
Explanation:
(A) Only eukaryotes have a nucleus.
(B) Both replicate the DNA before performing cell division, so each cell keeps a copy.
(C) This structural feature is called centromere in eukaryotes and in bacteria this role is played by the origin of replication.
(D) Centromeres are eukaryotes exclusive.
(E) Only bacteria have a replication origin.
Hairs are mostly fibrous proteins and are composed of keratin, and also the main constituent of skin, nails, wool, woof, feathers etc.
Keratin is the essential fibrous protein which has a structural and protective functions in the epithelium.
The question must refer to the modern classification system in biology.
It started with the work of Linnaeus - so its early version can be called a Linnaean classification - but right now it has been expanded and changed to fit the evolutionary relationships between the species - which is the best description, i.e. the answer is "it is based on the evolutionary relationship of the species"
