In multicellular organisms, most cells:

Scientists were monitoring a meteor headed toward Earth. It moved off course, but some pieces of rock entered the Earth’s atmosp

abruzzese [7]

<h2>Answer:</h2>

Mesosphere

<h2>Explanation:</h2>

The atmospheric layer that protects the Earth against danger of the rocks is the mesosphere. This layer is above the stratosphere. The temperature drops in this layer to about -100 degrees Celsius. This is the coldest region of the atmosphere. The mesosphere burns up most meteors and asteroids before they are able to reach the earth's surface. It becomes cold enough to freeze water vapor in its atmosphere into ice clouds.

3 0

3 years ago

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Does geographic distance between salamander populations increase their reproductive isolation? To answer this question, research

Nataly_w [17]

Question: Does geographic distance between salamander populations increase their reproductive isolation? To answer this question, researchers studied populations of the dusky salamander (Desmognathus ochrophaeus) living on different mountain ranges in the southern Appalachian Mountains. The researchers tested the reproductive isolation of pairs of salamander populations by leaving one male and one female together and later checking the females for the presence of sperm. Four mating combinations were tested for each pair of populations (A and B)—two within the same population (female A with male A and female B with male B) and two between populations (female A with male B and female B with male A). The proportion of successful matings for each mating combination was measured. For example, when all the matings of a particular combination were successful, the researchers gave it a value of 1; when none of the matings were successful, they gave it a value of 0. Then the researchers calculated an index of reproductive isolation that ranged from 0 (no isolation) to 2 (full isolation). The reproductive isolation value for two populations is the sum of the proportion of successful matings of each type within populations (AA + BB) minus the sum of the proportion of successful matings of each type between populations (AB + BA).

The table (Figure 1) provides data for the geographic distances and reproductive isolation values for 27 pairs of dusky salamander populations.

Part A - Understanding experimental design

What hypothesis did the researchers test in this study?

Answer:

"Reproductive isolation increases with geographic distance between dusky salamander populations"

Explanation:

The mechanisms of reproductive isolation are a assemblage of evolutionary mechanisms, behaviors and physiological procedures dangerous for speciation. They avert followers of dissimilar types from manufacturing offspring, or confirm that any offspring are germ-free. While in allopatric speciation the reproductive isolation is resolute superficially by the spatial isolation of populations, during sympatric speciation specific groups of persons create distinct mating organizations with self-like persons while distribution the similar home with the rest of the unique inhabitants.

3 0

3 years ago

La polidactilia en la especie humana se debe a un alelo dominante. Entre Francisco y Martha, ambos abuelos de Santiago, uno de e

lesya [120]

Answer:

Abuelo/a con polidactilia heterocigoto, Pp
Abuelo/a normal, pp
Juan normal, pp
Esposa de Juan con polidactilia, PP o Pp
Santiago con polidactilia, Pp

Explanation:

<u>Datos disponibles</u>:

Polidactilia es causada por un alelo dominante, P.
El alelo recesivo p produce numero normal de dedos.
Francisco y Martha → Abuelos → uno de ellos con polidactilia
Juan → Hijo → Normal, pp
Santiago → Nieto → Polidactílico

Uno de los padres, ya sea Francisco o Martha, es polidactílico, lo que implica que ésta persona tiene, por lo menos, un allelo dominante en su genotipo, P- (El simbolo "-" esta representando un alelo dominante o uno recesivo).

Si Juan es normal, entonces su genotipo es pp, lo que significa que recibió un alelo recesivo de su padre y otro de su madre. Es decir que el parental policactílico es heterocigota, de forma que pudo heredarle un alelo recesivo a Juan. El otro parental probablemente sea normal, pp, pudiendo solo heredarle a Juan el alelo recesivo.

Entonces, uno de los padres tiene genotipo Pp (heterocigota) y el otro pp (homocigota recesivo).

Juan es norma, pp.

Santiago, hijo de Juan, es polidactílico, lo que implica que lleva en su genotipo por lo menos un alelo dominante, P. Pero Juan solo pudo heredarle un alelo recesivo, p. Por lo tanto, Santiago es heterocigota para la característica, Pp, y heredó el alelo dominante de su madre, que puede ser homcigota dominante PP o heterocigota Pp.

Supongamos que Francisco es polidactílico y Martha normal.

<u>1º Cruza</u>: Francisco x Martha

Parentales) Pp x pp

Gametas) P p p p

F1) 1/2 = 50% Pp

1/2 = 50% pp → Juan

<u>2º Cruza</u>: Juan x Esposa (opción uno: esposa homocigota dominante)

Parentales) pp x PP

Gametas) p p P P

F2) 4/4 = 100% Pp → Santiago

<u>2º Cruza</u>: Juan x Esposa (opción dos: esposa heterocigota)

Parentales) pp x Pp

Gametas) p p P p

F2) 1/2 = 50% Pp → Santiago

1/2 = 50% pp

6 0

3 years ago

HELP WILL GIVE BRANLIEST!!

nalin [4]

Answer:

The answer is B Ribosomes.

4 0

3 years ago

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All you need is in the photo

Leni [432]

Answer:

I Belive its the 3 one

Explanation:

4 0

3 years ago