Answer:
Certain fossils, called index fossils, help geologists match rock layers. To be useful as an index fossil, a fossil must be widely distributed and represent a type of organism that existed for a brief time period. Index fossils are useful because they tell the relative ages of the rock layers in which they occur.
The parts of the circulatory system include the heart, the lungs, and all the veins and arteries.
The answer is none of the above
Answer:
c. 28
Explanation:
Plant A has a dipoid chromosome number of 12, so its gametes will have an haploid number of 6 chromosomes.
Plant B has a dipoid chromosome number of 16, so its gametes will have an haploid number of 8 chromosomes.
<h2><u>Plant A</u> <u>Plant B</u></h2><h2>2n = 12 2n = 16</h2><h2> n = 6 n = 8</h2><h2 />
The new species C arises as an allopolyploid from A and B. An allopolyploid usually originates from the breeding of two different species.
In this case, <u>a gamete from plant A combines with a gamete from plant B to form a hybrid with 14 chromosomes</u> (6 from A and 8 from B). These chromosomes are unpaired, so the hybrid is sterile.
In order to become a fertile diploid individual of species C, the most common mechanism is polyploidization, where the genome duplicates. <u>That way, the resulting plant C has a diploid number of 14 x 2 = 28 chromosomes</u>, of which 12 are A and 16 are B.
Answer:
In the scientific world, theory can be described as a detailed explanation of any phenomenon occurring in nature. A scientific theory is tested through hypothesis and is supported through facts, but as advances are made in the scientific world, the theory is subjected to change with time. For example, in the past, many modifications were made in the atomic theory. The atomic theory describes the structure of an atom.
