Answer:
Radiation and mutations can cause changes in the DNA but there arent substances. Ribonucleic acids can cause errors if they match with the wrong acid.
The third one is the product of cellular respiration
Answer:
Scientists consider phylogenetic trees to be a hypothesis of the evolutionary past since one cannot go back to confirm the proposed relationships.
Explanation:
Basically it is a hypothesis from before hypothesis actually were called hypothesis
Answer:
Multiple Sclerosis is an inflammatory disease in which myelin sheath of nerve cells of brain and spinal cord are damaged.
Explanation:
Cause:- (Exact cause of inflammation is not known)
- But damage is caused due to attack by autoimmune cells or antibodies against myelin sheath.
Types of tissues attack:-
- Oligodendrocytes and myelin sheath is damaged and stripped away from axon and the process is known as demyelination.
- Myelin sheaths are made up of fatty tissues and help in transmission of electric impulse.
Result of immune system attack:-
- Damaged myelin sheath stop forming whIte matter of central nervous system.
- Hence disrupt coordinating communication between different brain regions.
Signs and symptoms:- vary from person to person
- Diminished eyesight.
- Disrupt motor coordination.
- Weak sensory perception.
- Fatigue and dizziness.
- Speech disorder.
- Muscle weakness and spasticity.
- Difficulty in urination and stool.
Diagnosis and treatment:-
- Diagnosis include MRI T2 findings and cerebrospinal fluid specific oligoclonal bands.
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