Answer:
The correct answer is - option e.)
Explanation:
The experiment that was performed by Meselson and Stahl was created to prove that DNA replication is a semiconservative process.
When Bacteria grow on 15N media they incorporate the isotype of nitrogen and after few generations, the culture moved to 14N media where it incorporates as they replicate in semi-conservative mode and one DNA strand comes from the Parent DNA.
The right option for question one is Option (e) Run as one band, at a position expected for DNA containing a 14N:15N ratio equal to 1.
The best answer is b - it is rigid.
The cell wall is defined as the rigid, outermost layer found in plants and also certain bacteria, algae and fungi. It is absent in animal cells.
The plant cell wall is made up cellulose which is a structural carbohydrate. The cell wall is rigid and thus offers structural support allowing plant such as trees to grow to great heights.
It also helps prevent water loss, helps protect against insects and pathogens and keeps the shape of the plant.
Answer:
The correct answer is the letter b. The endosymbiotic event that brought chloroplasts into Eukaryotic cells actually happened after Eukaryotic lineages diverged so many lineages never actually possessed chloroplasts
Explanation:
The plastid is an organelle linked to membarna found in the cells of eukaryotic organisms, which contains pigments used in photosynthesis. Some eukaryotic organisms over time have inherited the ability to photosynthesize from cyanobacteria by secondary endosymbiosis or ingestion, and are able to capture and sequester photosynthetic cells and chloroplasts, this process is known as kleptoplasty.
If a pesticide that inhibits acetylcholinesterase is present in a muscle, THE MUSCLE WILL BE CONTRACTING REPEATEDLY.
The enzyme, acetylcholinesterase is the one responsible for the termination of muscle contraction, when this enzyme is deactivated, the muscle contraction will not be turned off and the concerned muscle will contracts repeatedly.
It’s c Xand Y good luck sweetie
