Answer:
A) A single base pair change.
Explanation:
Point mutation is a change in a single base pair of a nucleotide. This comes as a results of mistakes made during DNA replication, induced by ultravoilet radiations, extreme heat and X-rays. There are three types of point or substitution mutations; change, deletion and insertion. The nucleotide bases are either mistakenly inserted, changed or deleted, thus changing the resulting protein or amino acid being coded for.
Answer:
I believe the answer is d
Stem cells are undifferentiated cells that have the ability to differentiate into any kind of body cells like muscle, skin, heart etc.
There is alot of research being conducted on the stem cells because they have the potential to treat almost any kind of disease. This is because they are embryonic cells that can be specialized into a person's any type of body cells. When stem cells are specialized into the any kind of body's cells like cardiac, muscular, they can repair all the damaged cells and replace them with the new and healthy cells.
Currently, they are being used to repair:
- Nerve cells that are damaged due to some injuries like stroke, spinal injury, Parkinson’s disease, Alzheimer's and other such neurological disorders.
- They can repair insulin producing cells so millions of people can be treated against diabetes and other problems that arise due to diabetes like kidney and cardiac issues.
- They have the ability to repair almost any kind of injured tissue.
- They can provide clues of muscle re-pairment like how organs are repaired after an injury, trauma or problem like heart attack.
- Stems cells can be used to make new drugs and minimize the side effect of the drugs.
- This is a fascinating area of science that has the potential to repair any damaged organ of human without getting it replaced by a new one.
Hope it help!
Answer:
water act as a reactant in light reaction.
Explanation:
Water undergo hydrolysis in presence of sunlight to form proton(H+) and hydroxyl ion(OH-) ion. The OH- ion liberates electron to reaction center of photosystem 1 thereby exciting the later .The excited photosystem then donates that extra electron to the primary electron acceptor and from the primary electron acceptor the electron moves through various electron carriers to generate ATP .
Basically water act as reducing agent in photosynthesis process.
Answer:
there are two types of cell one eukaryotic cell that have true nucleus (genetic material enclosed in membrane) and membrane bounded organelles and other is prokaryotic cell that donot have have true nucleus (genetic material dispersed in cytoplasm) and membrane bounded organelles.
similarities between PC and EC is that both contains cell membrane, ribosomes (not a membrane bounded organelle) .
examples of PC are bacteria , paramecium,fungi etc
examples of EC are plant and animal cells
there are two names for cell membrane i.e plasmalemma, cell surface membrane,
selectively permeable or semipermeable means cell only allows those material to pass through its cell membrane which it needs.this cell'ability is important because to protection against the poisonous substance and to maintain cell needs .
