Answer:
Apoptosis does not involve:
c. lysis of the cell
Explanation:
Apoptosis is a programmed cell death that occurs under normal physiological conditions and in a controlled manner. Normally seen in cell turnover, embryogenesis, also involved in processes of immune, nervous and endocrine systems.
The main morphological and biochemical changes seen during the apoptosis are the fragmentation of DNA by endonucleases, nuclear, chromatin and cytoplasmatic condensation, apoptotic bodies formation (membrane bound-vesicles form of cell parts) and the phagocytosis (digestion) of those bodies by the scavenger cells.
Apoptosis is regulated by cell- signaling pathways, the caspases, a family of cysteine proteases, are the ones involved in the process.
In the process there is no lysis of the cell as this could lead to a inflammatory response (just happens in necrosis) which would affect contiguous cells, and will involve immune cells. In apoptosis there is just a membrane blebbing, but it does not loss its integrity.
Precipitation.....................
Answer: Substances that are protein based cannot cross the lipid cell membrane, but can exert their effect by binding to the proteins based receptors present on the lipid bilayer.
Explanation:
Hormones such as calcitonin , Parathyroid hormone and pituatry horomones are proteins and water soluble.They cannot cross lipid bilayer but can bind to ligand binding protein receptors.
These receptors are protein macromolecules that are specific in nature for specific hormones.
After binding to the receptors, these hormone-recpetor complexes activate second messengers and regulate the downstream effects.
The group in which a star is classified according to its spectrum, especially using the Harvard classification.
Answer:
Sunlight and heat react with gases in the atmosphere.
Explanation:
Smog forms purely as a result of air pollution.
Gases released from machines on earth rise up the sky.
The risen gases then meet and react with the sun plus fine particles in the atmosphere, smog forms.
Smog causes a lot of problems on earth among them being:
- Accidents due to the blurry effect causedv by smog on roads thereby distructing drivers.
