Answer:
A medida que la Tierra se enfrió, se formó una atmósfera principalmente a partir de gases arrojados por los volcanes. Incluía sulfuro de hidrógeno, metano y de diez a 200 veces más dióxido de carbono que la atmósfera actual. Después de aproximadamente 500 millones de años, la superficie de la Tierra se enfrió y solidificó lo suficiente como para que el agua se acumulara en ella.
Explanation:
lo siento, no soy español y usé el traductor de google
The recombination frequency of the two gene pairs is 3%.
The number of recombinant offspring(r.o.) / total number of offspring x 100% = recombination frequency(θ):
r.o./total x 100% = θ
30/100 x 100% = 3%
Recombinant offspring are children that have a different allele combination to their parents.
For example, say a mother has a haploid cell with the alleles AB and the father has a haploid cell with the alleles ab. These combine to make a diploid cell with the sequence Aa+Bb.
Formation of Recombinant Offspring :
Recombination can happen in two different ways; independent assortment and crossing over.
- Independent assortment is when the maternal and parental DNA are mixed during meiosis, creating a new gene sequence.
- Crossing over happens during the first stage of meiosis when the two homologous chromosomes are paired and a portion breaks off on the same loci then reconnects to a different end. Crossing over can only happen when there isn't a physical linkage of the parental alleles.
Recombination frequency (θ) is the frequency with which a single chromosomal crossover will take place between two genes during meiosis. A centimorgan (cM) is a unit that describes a recombination frequency of 1%. In this way we can measure the genetic distance between two loci, based upon their recombination frequency. This is a good estimate of the real distance. Double crossovers would turn into no recombination. In this case we cannot tell if crossovers took place. If the loci we're analysing are very close (less than 7 cM) a double crossover is very unlikely. When distances become higher, the likelihood of a double crossover increases. As the likelihood of a double crossover increases we systematically underestimate the genetic distance between two loci.
When two genes are close together on the same chromosome, they do not assort independently and are said to be linked. Whereas genes located on different chromosomes assort independently and have a recombination frequency of 50%, linked genes have a recombination frequency that is less than 50%.
To learn more about Recombination frequency : brainly.com/question/7299933
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Answer:
See below
Explanation:
The heat source for our planet is the sun. Energy from the sun is transferred through space and through the earth's atmosphere to the earth's surface. Since this energy warms the earth's surface and atmosphere, some of it is or becomes heat energy. There are three ways heat is transferred into and through the atmosphere:
<u>radiation: </u>Radiation is the transfer of heat energy through space by electromagnetic radiation. If you have stood in front of a fireplace or near a campfire, you have felt the heat transfer known as radiation.
<u>conduction:</u> Conduction is the transfer of heat energy from one substance to another or within a substance. Have you ever left a metal spoon in a pot of soup being heated on a stove? After a short time, the handle of the spoon will become hot.
<u>convection: </u>convection is the transfer of heat energy in a fluid. This type of heating is most commonly seen in the kitchen with a boiling liquid.
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