The following statements accurately reflect the beliefs on Earth's early history:
B. Scientists believe the early atmosphere lacked the oxygen necessary to support modern human life.
The following statements are incorrect:
A. Scientists believe that DNA may have existed before RNA - Scientists actually believe the opposite - RNA may have existed before DNA.
C. Scientists believe that microspheres nearly prevented the development of early life.
D. Scientists believe that oxygen was plentiful in the early atmosphere - again, scientists believed the opposite
Answer:
Parts of the U.S. state of Alaska and the countries of Canada, Greenland, Iceland, Norway and Russia are all in the Arctic tundra biome. Regardless of how cold and bleak the weather may be in the northern contiguous states in the middle of winter, technically, the tundra does not extend below northernmost Canada
Explanation:
Answer:
The different species present in an ecosystem make the ecosystem balanced. The species of an ecosystem interact with one another in one form or the other. For example, the presence of a plant species will provide food for the abundant types of herbivores present in an ecosystem. A predator might feed on many types of preys. Hence, the presence of different preys will reduce the chances of a species from becoming wiped out from the ecosystem. Hence, all the organisms in an ecosystem are dependent on another in some way or the other.
Answer:
<u> The following four traits are -: </u>
- <u>Pedigree 1 -</u> A recessive trait (autosomal recessive) is expressed by pedigree 1.
- <u>Pedigree 2- Recessive inheritance is defined by Pedigree 2. </u>
- <u>Pedigree 3</u> - The inheritance of the dominant trait (autosomal dominant) is illustrated by Pedigree 3.
- <u>Pedigree 4-</u> An X-like dominant trait is expressed by Pedigree 4.
Explanation:
<u>Explaination of each pedigree chart</u>-
- Pedigree 1 demonstrates the <u>recessive trait </u>since their children have been affected by two unaffected individuals. If the characteristics were X-linked, in order to have an affected daughter, I-1 would have to be affected.
In this, both parents are autosomal recessive trait carriers, so the child will be affected by a 1/4 (aa) - <u> Recessive inheritance</u> is defined by <u>Pedigree 2</u>. This is<u> X-related inheritance as autosomal recessive</u> inheritance has already been accounted for in part 1. This inference is confirmed by evidence showing that the father (I-1) is unaffected and that only the sons exhibit the characteristic in generation II, suggesting that the mother must be the carrier. The individual I-2 is a carrier for this X-linked trait. A typical Xa chromosome is attached to the unaffected father (I-1), so the chance of carrier II-5 is 1/2. Probability of an affected son = 1/2 (probability II-5 is a carrier) x 1/2 (probability II -5 contributes (
) x 1/2 (probability of Y from father II-6) = 1/8. An affected daughter's likelihood is 0 because a typical
must be contributed by II-6. - The inheritance of the<u> dominant trait</u> is demonstrated by <u>Pedigree 3 </u>because affected children still have affected parents (remember that all four diseases are rare). The trait must be <u>autosomal dominant</u> because it is passed down to the son by the affected father. There is a 1/2 risk that the heterozygous mother (II-5) would pass on mutant alleles to a child of either sex for an autosomal dominant feature.
- <u>Pedigree 4</u> is an <u>X-linked dominant function</u> characterized by the transmission to all of his daughters from the affected father but none of his son. On the mutant X chromosome, the father (I-1) passes on to all his daughters and none of his sons. As seen by his normal phenotype, II-6 therefore does not bear the mutation. An affected child's likelihood is 0.
In the question the pedigree chart was missing ,hence it is given below.
Answer:
C Matter and energy can be credited or destroyed