Answer:
DNA is made of chains of four smaller molecules called "Nucleotides".
Explanation:
A molecule consisting of a nitrogen-containing base (adenine, guanine, thymine, or cytosine) in DNA is known as a nucleotides.
The geologic features that help scientists to determine the relative ages of rocks by their positions include index fossils, intrusions, and cross-cutting relationships (Option d).
<h3>What does geological age mean?</h3>
The expression geological age refers to the relative age of a given rock and or fossil (i.e. a piece or trace of dead organism) in a geological time scale.
In conclusion, the geologic features that help scientists to determine the relative ages of rocks by their positions include index fossils, intrusions, and cross-cutting relationships (Option d).
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Answer:
The spinal cord is made up of bundles of nerve fibers. It runs down from the brain through a canal in the center of the bones of the spine. These bones protect the spinal cord. Like the brain, the spinal cord is covered by the meninges and cushioned by cerebrovascular fluid.
lol im only 14!
Answer:
A single gene on the Y chromosome plays a crucial role in the parental development of the testes.
Explanation:
Y chromosome is present only in males and this chromosomes is the distinguishing factor which separates males from females. It is the smallest chromosome but of utmost importance due to its sex determining feature. Up till now, studies show that Y chromosomes only carry limited amount of genes.
The Y chromosome, most importantly, comprises of the SRY gene. This is the gene responsible for determining the testis and for the development of the testis. The SRY gene is responsible for sex determination.
Multiply 5730 years by 2 since two half-lives have gone by for carbon.
<u>Explanation</u>:
The half-life of a radioactive isotope depicts the measure of time that it takes half of the isotope in an example decay. On account of radiocarbon dating, the half-existence of carbon 14 is 5,730 years
The half-life of carbon-14 is 5730 years.
In this manner, after
1 half-life there is 50 % = 1/2 of the first amount left.
2 half-lives there is 25 % = 1/4 of the first amount left.
25% is two half-lives.
Every 50% of life requires 5730 years.
So two half-lives require 2 × 5730
