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3 years ago

Neurotransmitters are released from axon terminals via

Biology

1 answer:

love history [14]3 years ago

6 0

Answer:

Neurotransmitters are released from axon terminals via exocytosis

Explanation:

Dendrite is the receiving part of the presynaptic neuron, while axon is the transmitting part of the neuron. So, after initiation, action potentials travel down axons to the terminals. Action potential travels through the membrane of the presynaptic cell causing the voltage-gated channels permeable to calcium ions to open. Ca2+ flow through the presynaptic membrane and increase the Ca concentration in the cell which will activate proteins attached to vesicles that contain a neurotransmitter (e.g. acetylcholine). Vesicles fuse with the membrane of the presynaptic cell, thereby release their contents into the synaptic cleft-space between the membranes of the pre- and postsynaptic cells (exocytosis of the vesicle's content). Neurotransmitter ACh (from the vesicles) binds to its receptors on the postsynaptic membrane and its binding causes depolarization of the target cell (muscle cell). Depolarization occurs because sodium enters the cell as a result of neurotransmitter receptor binding.

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In chickens, comb shape is determined by genes at two loci (R, r and P, p). A walnut comb is produced when at least one dominant

Ivenika [448]

Answer and Explanation:

Available data:

Comb shape is determined by genes at two loci (R, r and P, p).

The walnut comb genotype is R_P_.

The rose comb genotype is R_pp.

The pea comb genotype is rrP_.

The single genotype is rrpp.

a. Walnut crossed with single produces 1 walnut, 1 rose, 1 pea, and 1 single offspring:

Parental) RrPp x rrpp

Gametes) RP Rp rP rp rp rp rp rp

Punnet Square) RP Rp rP rp

rp RrPp Rrpp rrPp rrpp

rp RrPp Rrpp rrPp rrpp

F1 phenotype: 25% walnut, 25% rose, 25% pea, and 25% single.

F1 genotype: 4/16 RrPp, 1/16 Rrpp, 4/16 rrPp, 4/16 rrpp.

b. Rose crossed with pea produces 20 walnut offspring.

Parental) RRpp x rrPP

Gametes) Rp Rp Rp Rp rP rP rP rP

Punnet Square) Rp Rp Rp Rp

rP RrPp RrPp RrPp RrPp

F1 phenotype: 100% walnut.

F1 genotype: 16/16 RrPp.

c. Pea crossed with single produces 1 single offspring.

This is not possible, because the pea genotype involves at least one dominant allele P. There are two possible crosses: rrPp x rrpp, which must produce half of the progeny pea and the other half single, or rrPP x rrpp which produce a whole pea progeny with no single offspring.

Parental) rrPp x rrpp

Gametes) rP rp rP rp rp rp rp rp

Punnet Square) rP rp rP rp

rp rrPp rrpp rrPp rrpp

rp rrPp rrpp rrPp rrpp

F1 phenotype: 50% pea, and 50% single.

F1 genotype: 8/16 rrPp, 8/16 rrpp.

d. Rose crossed with pea produces 2 walnut, 1 single, and 1 pea offspring.

This is not possible, because having one of the parents with a rose phenotype involves at least one R allele, which means that there must be rose phenotype in the progeny.

Parental) Rrpp x rrPp

Gametes) Rp Rp rp rp rP rP rp rp

Punnet Square) Rp Rp rp rp

rP RrPp RrPp rrPp rrPp

rP RrPp RrPp rrPp rrPp

rp Rrpp Rrpp rrpp rrpp

rp Rrpp Rrpp rrpp rrpp

F1 phenotype: 25% walnut, 25% rose, 25% pea, and 25% single.

F1 genotype: 4/16 RrPp, 1/16 Rrpp, 4/16 rrPp, 4/16 rrpp.

e. Rose crossed with single produces 31 rose offspring.

Parental) RRpp x rrpp

Gametes) Rp Rp Rp Rp rp rp rp rp

Punnet Square) Rp Rp Rp Rp

rp Rrpp Rrpp Rrpp Rrpp

F1 phenotype: 100% rose (31 individuals equal 100% of the progeny).

F1 genotype: 16/16 Rrpp.

f. Rose crossed with single produces 10 rose and 11 single offspring.

Parental) Rrpp x rrpp

Gametes) Rp Rp rp rp rP rP rp rp

Punnet Square) Rp Rp rp rp

rp Rrpp Rrpp rrpp rrpp

F1 phenotype: 50% rose, 50% single.

F1 genotype: 8/16 Rrpp, 8/16 rrpp.

3 0

3 years ago

What are the steps of passive transport

svetoff [14.1K]

The molecules doesn't need energy to cross through.
The diffusion doesn't need protien, the molecules pass between phospholipids by passes protien. It moves smaller molecules. Facilitated need protien also hormone, and larger molecules.
I wish it makes sense.

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3 years ago

_____ is the best example of a sensitive period.

Katarina [22]

The best example that illustrates a sensitive period is letter b, where the child tries to learn in speaking a second language because this is considered to be a sensitive period in which is the period for a development of new opportunities that a child could learn in which learning to speak a second language is considered to be a sensitive period.

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3 years ago

Explain 3 main steps in the process of DNA replication

podryga [215]

Didn't mean to post this. sorry!

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3 years ago

What is the impact of the depletion of fishing stocks?

ziro4ka [17]

It is the same as creating more pests or setting up dominant species which upset the ecological food pyramid leading to decimation of trophic levels or predators and energy cycling. Fishes feed on microscopic algae and animals the primary base of the food chain in water, if they are not checked they will choke the rivers and oceans causing toxic waters. Fish feed to contain them, in the process they grow and increase in numbers but their population is checked by bigger fishes and so on till it reaches a top predator which is usually a large animal.

3 0

3 years ago

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