A population crisis usually occurs in a country that has:

What makes two isotopes of the same element different from each other?

Answer:

An isotope is one of two or more forms of the same chemical element. Different isotopes of an element have the same number of protons in the nucleus, giving them the same atomic number, but a different number of neutrons giving each elemental isotope a different atomic weight.

Explanation:

pretty sure its D

7 0

2 years ago

Suppose two independently assorting genes are involved in the pathway that determines fruit color in squash. These genes interac

makvit [3.9K]

Answer:

100% yellow fruit color, Yyww.

Explanation:

Available data:

two independently assorting genes

the W allele codes for a dominant white phenotype

w allele codes for a colored squash

The allele Y codes for a dominant yellow phenotype

the allele y codes for a recessive green phenotype

The phenotypes from the first locus will always mask the phenotype produced by the second locus if the dominant allele (W) is present at the first locus. This masking pattern is known as dominant epistasis

Epistasis means "interruption" and refers to interactions between genes located in different loci in the same chromosome. An “epistatic gene” can alter, influence, or suppress the expression of a "hypostatic gene". When the epistatic gene is dominant, the interaction is known as "dominant epistasis".

W suppresses the expression of Y and y, this means that whenever W is present, the fruit is white. If W is not present, the fruit color can be expressed.

So, the proposed cross in the present problem occurs between a green fruited individual and yellow fruited individual, which suggests that W is absent.

Genotype for Green fruit: yyww

Genotype for purebred Yellow fruit: YYww

Cross:

Parental) YYww x yyww

Gametes) Yw Yw Yw Yw yw yw yw yw

Punnet square) Yw Yw Yw Yw

yw Yyww Yyww Yyww Yyww

F1) 100% Yellow fruited plants, Yyww

As these two genes assort independently, we can also represent the cross for each gene by separate, like this:

For w gene:

Parental) ww x ww

Gametes) w w w w

Punnet square) w w

w ww ww

F1) 4/4 or 100% colored-fruits

For Y gene:

Parental) YY x yy

Gametes) Y Y y y

Punnet square) Y Y

y Yy Yy

F1) 4/4 or 100% yellow fruits, Yy.

3 0

3 years ago

A nurse is caring for a client who has a prescription for digoxin. what are manifestations for digoxin toxicity that the nurse s

AlexFokin [52]

Digoxin toxicity is a poisoning that occurs in people due to excessive intake of the medication digoxin or the consumption of plants such as foxglove and lily of the valley that contain digoxin. Manifestations for digoxin toxicity that the nurse should monitor for before administering this medication are vomiting, loss of appetite, confusion, blurred vision, arrhythmias, decreased energy, and irregular heartbeat. The nurse should also closely monitor the electrolyte levels because low levels of potassium and magnesium increase the risk for digoxin toxicity. If digoxin is administered, the heart rate should be counted before every dosage. If the heart rate is lower than 60 beats per minute, the drug should be stopped and the health care professional should be notified.

3 0

3 years ago

Please describe the signal transmission across a myoneural junction that allows the nervous system to move the muscles of a foot

Tems11 [23]

The contraction of the muscles (whether at the level of the arms or the legs) and more specifically the muscular fibers of the musculoskeletal system, that is to say organs, in the broad sense of the term, allowing the movement, is normally under the total dependence of the nerves which transmit a nervous command.

This command can be considered as a voluntary order (from the cerebral cortex). This nerve impulse then takes the direction of the spinal cord where it is directed by a series of nerves called relays to route the nerve impulse (order) to the muscles.

Then the nerve impulse propagates along the axon and when it reaches the motor plate it causes the release of a substance called neurotransmitter: acetylcholine. The neuroreceptor, in the motor plate, receives the nerve signal that the end of the axon transmits to it by a chemical mediator. Acetylcholine binds to the receptors, triggering a contraction of the muscle cell.

More precisely, acetylcholine is enclosed in vesicles (a kind of tiny sphere-shaped grains) located within the nervous corpuscles located at the end of each neuron. When nerve impulses (stimulation) reach the presynaptic membrane, acetylcholine is released and diffuses into the synaptic cleft (about 50 nanometers wide) filling it. Acetylcholine will at this time bind very briefly to receptors located after the synapse (postsynaptic) and trigger the opening of sodium channels (followed by their closure and an opening of potassium channels). These channels are tiny tubules allowing the passage of ions (atom having lost or gained an electron).

This results in the propagation of an "electric charge" action potential at the origin of the passage of the nerve impulse, in other words of the order given by the brain or by the autonomic nervous system.

After this first step acetylcholine is then released and degraded by an enzyme called acetylcholinesterase (AChE) located in the synaptic cleft but also on the postsynaptic membrane. The choline thus released is then recaptured by the presynaptic bodies and reused for the synthesis of new acetylcholine molecules.

Acetylcholine is involved in the control of muscles via neuromuscular terminations and viscera or glands and sometimes both. This is how it intervenes to make also work for certain organs like the heart, the salivary glands, the sweat glands, the bladder, the bronchi, the eyes, intestine etc.

A variety of enzymes called cholinesterases allow the rapid inactivation of acetylcholine. The chemical reaction that causes the contraction of the muscle fiber is a brief phenomenon. Indeed, acetylcholine is very rapidly degraded by cholinesterases. As a result, acetylcholine itself cannot be used in drug form. Nevertheless to circumvent these difficulties other drugs reproduce or prevent the effects of this neuromodulator. These are agonists or antagonists respectively.

The muscular fiber is an elongated cell used in the composition of the muscle, which is a fleshy organ with the property of contracting and relaxing. Each muscle cell is surrounded by a membrane containing a cytoplasm called sarcoplasm with myofibrils which are elongate filaments parallel to the major axis of the cell.

5 0

3 years ago

During the performance of the simple staining procedure, you failed to heat fix your

lbvjy [14]

. excess water on the slides will boil during fixation. Why should you be careful . During theperformance of the simple staining procedure, you failed to heat fix your E. coli smear preparation.Upon microscopic examination, how would you expect this slide to differ from the correctly prepared slides? When heat fixing the.

4 0

2 years ago