Answer:
The phylum Hemichordata is the one that could form an evolutionary connection between the chordates and non-chordates.
Explanation:
To the phylum Hemichordata belongs a genus that scientists believe could explain how the chordates could evolve from the non-chordates. This genus is Balanoglossus, of the class Enteropneusta.
Balanoglossus is similar to a worm, whose habitat is the seabed, and like other hemicordates it has a stomach, a structure that forms part of its digestive system and fulfills the functions of a spine.
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Chordates and non-chordates brainly.com/question/1387264
Answer:
-Histamine binds extracellularly to the H1 receptor.
-When histamine binds to the H1 receptor. the receptor undergoes a conformation change and binds the inactive G protein.
-Once the G protein is active, it binds to the enzyme phospholipase C, activating it.
-Histamine is likely hydrophilic.
When histamine encounters a target cell, it binds extracellularly to the H1 receptor, causing a change in the shape of the receptor. This change in shape allows the G protein to bind to the H1 receptor, causing a GTP molecule to displace a GDP molecule and activating the G protein. The active G protein dissociates from the H1 receptor and binds to the enzyme phospholipase C, activating it. The active phospholipase C triggers a cellular response. The G protein then functions as a GTPase and hydrolyzes the GTP to GDP. The G protein dissociates from the enzyme and is inactive again and ready for reuse.
Explanation:
Answer:
the correct choice is B
located roughly between the orbits of the planets Mars and Jupiter. It is occupied by numerous irregularly shaped bodies called asteroids or minor planets.
Answer:
The correct answer is - option D. lytic cycle.
Explanation:
The lytic cycle is one of the two viral reproduction cycle. Generally, it is the major reproduction cycle. In this cycle reproduction of the viruses takes place inside the host cell and produce more viruses. In the production of the more viruses the host cell and it''s destruction takes place in the end. The 5 steps that takes place are as follows:
1- attachment - viruses attach to the cell.
2-penetration- only nucleic acid or genetic material is injected into the host cell through the hole made by the tail fibers and enzymes.
3- synthesis - replication of viral nucleic acid and protein and envelope.
4- assembly - assembling of the new viruses formed.
5- release.
Thus, the correct answer is - option D.
Answer:
C. Point B
Explanation:
The exposed curve represents a logistic growth model. Population growth depends on density. Natality and mortality depend on the population size, meaning that there is no independence between population growth and population density.
When a population grows in a limited space, density rises gradually and eventually affects the multiplication rate. The population per capita growth rate decreases as population size increases. The population reaches a maximum point delimited by available resources, such as food or space. This point is known as the carrying capacity, K.
K is a constant that equals population size at the equilibrium point, in which the natality and the mortality rate get qual to each other.
Referring to population size as N, when
- N<K, the population can still grow.
- N approximates to K, the population´s growth speed decreases.
- N=K the population reaches equilibrium,
- N>K, the population must decrease in size because there are not enough resources to maintain that size.
The sigmoid curve represents the logistic growth model.
- Point A: During this period, the population size is relatively stable. Little growth is expressed.
- Point B: At the beginning of this period, population growth increases softly. The more individuals are in the population, the more that reaches sexual maturity and get to reproduce, leaving fertile offspring. This fertile offspring also get to reproduce and leave more fertile individuals. At the end of the period, the curve shows a sharp slope, reflecting the significant increase in the population reproductive rate.
- Point C: At the beginning of this period, the population keeps on growing exponentially. But at the end of the period, the curve tends to stabilize, meaning that the population stops growing in size so fast. The population slow and gradually reaches the equilibrium point, K.
- Point D: The population got to stabilize.
