The correct option is this: TWO DRAGONFLY SPECIES REGULARLY MATE BUT THEIR GAMETES ARE INCOMPATIBLE.
In biology, there are different types of reproductive barriers, one of these is prezygotic barrier. A prezygotic barrier is a kind of mechanism that prevent reproduction from occurring by blocking fertilization. In this case, the concerned species will be mating together, but their gametes will not be compatible and thus, zygote will not be formed.
A postzygotic barrier on the other hand is said to occur when the reproduction process is blocked after the formation of zygote or after fertilization has taken place. A good example of this is an hybrid mule that is sterile and can not reproduce.
Answer: mutualism
Mutualism is a symbiotic relationship, between two organisms, living in close association with each other. In this relationship both the organisms gains benefit. Both organisms are dependent on each other for competing their life cycle.
The given situation is an example of mutualism because both the species are benefited for the relationship. Birds receive food from strawberries in turn birds disperse the seeds of strawberry to promote growth of more strawberry plants. Both organisms are interdependent on each other.
Explanation:
Synapses are junctions at axon terminals where they connect to dendrites of other neurons at these junctions chemical reactions occur in order to facilitate the passage of information as chemical signals. There are several neuron types which include sensory motor and into neurons which bridge the two.
1. At neuromuscular junctions, electrical signals are transmitted:
- The action potential travels along the membrane until the synapse where it’s electrical depolarization leads to the opening of channels allowing only sodium ions to enter
- these flow through a presynaptic membrane until the concentration is built up, activating ion sensitive proteins attached to vesicles containing neurotransmitters like acetylcholine
- this leads to changes in the proteins leading to the fusion with the membrane of the presynaptic cell, so vesicles are open and neurotransmitter is released. The neurotransmitter diffuses across to chemical receptors on the presynaptic cell where they bind temporarily. This increases the permeability of the sarcolema to Na+;a new action potential is generated
2. Contraction of the sarcomere occurs via several steps.
- This action potential in the muscle, travels along T-tubules, and Ca+ ions are released by the sarcoplasmic reticulum into the sarcoplasm
- Ca and troponin combine, pulling myosin filaments, exposing the actin filament's myosin binding sites
- cross-bridge formation occurs, leading to the sliding of filaments.
- ATP drives cross-bridge cycling while mysosin pulls on actin strands
- muscle fibers shorten and contract
- later ACH is degraded in the synapse. Na ions are not released, and the action potential is not transmitted.
- the Ca channels on the SR close, while Ca is reabsorbed stopping Ca-troponin binding, closing myosin binding sites on actin and leading to cross bridge separation. The muscle fiber relaxes in their resting states.
Learn more about the autonomic nervous system at brainly.com/question/10386413
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Answer:
1. FtsZ tubulin homolog
2. actin and tubulin
3. actin and tubulin
4. b. animals and bacteria
Explanation:
1. In bacteria, the binary fission process takes place when the cytoskeletal structure of the bacteria are assembled to form the contractile ring in the centre of the cell. The contractile ring in bacteria is composed of the Z-protein which is a tubulin homolog.
2. Plants: the plants divide by the cell plate formation and not the contractile ring formation. This is mediated by the actin, tubulin and vesicle produced from the dictyosomes.
3. Animals: a contractile ring attached to the plasma membrane is formed which is composed of the F-actin and tubulin.
4. Since the bacteria and animal cytokinesis involves the formation of the contractile ring and thus the same mechanism of cytokinesis.
The Answer Is Chemical Comosition
