Answer:
When analyzing data on the nitrogenous base content of the DNA of various species, the claims are supported by the data:
- <em>In any one species, the amount of adenine closely approximates that of thymine. </em>
- <em>In any one species, the amount of guanine closely approximates that of cytosine. </em>
- <em>The amounts of A, T, G, and C in DNA varies from species to species. </em>
<em>(options A, B and D)</em>
Explanation:
Organizing the data has to:
<u>Source of DNA A T G C </u>
Streptococcus 29.8 31.6 20.5 18.0
Yeast 31.3 32.9 18.7 17.1
Herring 27.8 27.5 22.2 22.6
Human 30.9 29.4 19.9 19.8
E. Coli 24.7 23.6 26.0 25.7
DNA is the molecule that contains the genetic information of each species, formed by sequences of nitrogenous bases Adenine, Thymine, Cytosine and Guanine.
Since Adenine and Thymine -as well as Cytosine and Guanina- are complementary, the percentage of them will be very similar in each DNA molecule.
The genetic information -which determines the physical and functional characteristics of each organism- is encoded in the DNA and is different for each species, so the percentages of nitrogenous bases vary from species to species.
Answer:
compound can be broken down into smaller compound or their basic element by chemical change
The left side of the heart collects oxygen-rich blood from the lungs and pumps it to the body. The left and right sides of the heart are divided by walls<span> called septums. There is an atrial septum that separates the right and left atriums, and a ventricular septum that separates the right and left ventricles.</span>
White blood cells (D) aid in the immune system to fight infections.
Answer:
A
Explanation:
a. contain checkpoints that determine if the cycle will continue.
b. help move chromosomes to the new daughter cells.
c. produce more chromosomes before the cell divides.
d. grow and produce enough cytoplasm to fill two cells.
<em />
<em>The correct answer would be that G1 and G2 contain checkpoints that determine if the cycle will continue or otherwise.</em>
The cell cycle generally has three checkpoints that happen at G1, G2, and M phase of the cycle.
At G1 checkpoint, the integrity of the DNA of the cell is assessed to ensure that there are no damages and other conditions such as size and energy reserve are checked.
At G2 checkpoint, the cell is assessed for proper chromosome duplication to ensure that there are no mistakes or damages. The size of the cell and the amount of protein are also checked to ensure that the cell is ready for the active division phase.
At M checkpoint, correct attachment of the spindle fiber to the kinetochore of the chromosomes is checked. This checkpoint is also known as the spindle checkpoint and it happens towards the concluding phase of the metaphase stage.
<u>The correct option is therefore, A.</u>
