The big bang theory states that the universe began approximately 10-20 billion years ago in an expansion of the universe emanating from an extremely compact point. The occurrence of super massive black holes contradict the big bang theory. Super massive black holes are found at the center of galaxies and is what keeps them together. Models do not explain how these would have formed if the big bang occurred the way it was proposed.
Answer:
4) Replacement of GDP by GTP on the Ga after interaction with an activated GPCR.
5) Conformational change in the Ga subunit causing a decreased affinity for the Gb g subunit.
2) Dissociation of Ga from the G protein complex.
6) Ga-subunit with its attached GTP activates an effector like adenylyl cyclase.
3) Production of a second messenger, like cAMP.
1) Activation of one or more cellular signaling proteins.
Explanation:
It is a signaling cascade initiated by G proteins. These G proteins function as molecular switches capable of activating signaling pathways in the presence of guanosine triphosphate (GTP), which is hydrolyzed in order to produce energy
After a tornado or a hurricane the local ecosystem will be very damaged, and when the wind stops blowing, or all the water is drained/dried, the ecosystem will start recovering:
- The earth will recover
- Plants will regrow.
- Animals will come back.
- The ecosystem will slowly rebuild.
Hope it helped,
BiologiaMagister
Answer:
A) The radial orientation of cellulose microfibrils in the cell walls of guard cells causes them to bow outward and open when the stomatal pore when turgid.
Explanation:
Stomata are pores on the surface of leaves that work as valves controlling the gas exchange in plants; they are bordered by a pair of curved guarded cells in charge of opening and closing by increasing or decreasing the stomatal pore area.
Guard cells walls structure consist of a combination of stiff cellulose microfibrils oriented along the circumference of the cells and a softer matrix material which makes it possible for stomata pore to open by increasing water pressure (turgor).
Option B states that when guard cells become turgid, they close the stomata. This is a false statement as we explained before.
Option C states that light (known stimulant for opening stomata) causes guard cells to become flaccid which is also false. Guard cells become turgid in order to open the stomatal pore.
Option A is correct.
Answer:
Microbes play an incredibly important role in research. Many of the breakthroughs in molecular biology, such as understanding how the genetic code works and how genes are used to make proteins, were made by scientists studying microbes in the laboratory
