The decay of uranium isotopes is used to provide information about the age of Earth.
<h3>
Explanation:</h3>
Isotopes of Uranium U-232, U-233 , U-234 , U-235 , U-236 , U-238 are used as fuel in nuclear reactors or as explosives for nuclear weapons. Uranium 238 is not very radioactive and it constitutes for nearly 99.3% of natural uranium on Earth and has the longest lifetime: its period is 4.5 billion years, about the age of Earth.
Use of radiometric dating techniques help in defining the age of substances (natural or man-made) using the known decay rates of radioactive elements. Each element has an individual decay rate and half life time.
Two Uranium isotopes (U-238 and U-235) are used for radiometric dating. Both the isotopes have different decay rates and half life period. Both are unstable and radioactive. Since two different isotopes produce two different decay clocks (one as a reference to other), it is beneficial in accurately determining the age of samples. The age of earth (rocks or other natural elements) can be easily determined using Uranium isotopes.
Answer:
a. all tall
Explanation:
If genotypically one of the parents is homozygous dominant and another one is heterozygous for plant height then phenotypically all their progeny will be tall.
Let us suppose, 'T' represents dominant allele and 't' represents recessive allele. Then the genotype of one parent who is homozygous dominant will be TT and genotype of another parent who is heterozygous will be Tt.
The cross is depicted in the attachment.
Here it may also be noted that genotypically two of the progeny will be homozygous dominant while two of the progeny will be heterozygous but phenotypically all the progeny will be 'tall'.
There are so many examples for that in different areas, like TPT1 experiment carried out in our lab recently.Here's one link: http://www.alfa-chemistry.com/tpt1-cas-167218-46-4-item-290583.htm
it may thats what ive read when i looked it up
<span>Human cells contain 23 chromosomes and has a total of 46
pairs of chromosomes. The answer is letter A. Depending on the length and
morphology, it has seven groups. They are arranged from largest to smallest. It
has 22 pairs of homologus chromosomes known as autosomes and 1 pair of sex chromosomes,
a total of 23 chromosomes. A male karyotype has a total of 46 chromosomes and
gives a pair of XY while a female karyotype has a total of 46 chromosomes and
gives a pair of XX. These pairing are responsible to the gender of the
offspring.</span>
