A geologist studies rocks and such
Answer:
1. Purines
2. States that DNA composition varies among species
3. Hydrogen Bond
4. Purines
<em>Answer to #2 is a little iffy </em>-- sorry
Explanation:
Pyrmidines have two rings
Purines have one ring
Complementary bases are connected by hydrogen bonds.
The correct answer is:
The principal cause of aneuploidy is chromosome nondisjunction during mitosis or meiosis. Polyploidy in nature can result either from the duplication of euploid chromosome sets from a single species or from the combining of chromosome sets from different species.
Aneuploidy is a phenomenon when there is the presence of an abnormal number of chromosomes in a cell (an extra or missing chromosome). Usually it appears as a result of improper cell division (chromosomes don’t separate) and it can cause many genetic disorders.
Polyploidy refers to a state when there are more than two sets of chromosomes (one from mother one from father). Triploid (three sets of chromosomes) and tetraploid (four sets of chromosomes) chromosomes are examples of polyploidy. This phenomenon is most common in plants.
The nervous system and the muscle system respond to stimuli to produce motion. The skeletal movements of muscles are mostly voluntary.
Involuntary movements occur in these muscles when the nerve impulse passes from a sensory neuron to a motor neuron via an interneuron in the spinal cord.
<h3>What are Skeletal muscles?</h3>
Skeletal muscles may be defined as the muscles that fasten to your bones and authorize you to achieve a broad range of activities and operations.
Skeletal muscles control the direct movement of a person's will and are hence referred to as voluntary movement.
While the spinal cord is associated with both movements directly or indirectly. It is a prolonged, delicate tubelike network liable for holding incoming and outgoing messages through the brain to the rest body.
Therefore, it is well described above.
To learn more about Skeletal muscles, refer to the link:
brainly.com/question/1283837
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