Answer:
You can use these notes to answer your question
Answer:
All eight phenotypes are possible but parental phenotypes will be more in number
Explanation:
In the cross MmDdPp X mmddpp eight types of offspring are possible because MmDdPp will produce eight types of gametes. These offspring are:
- MDP/mdp
- Mdp/mdp
- mDp/mdp
- mdP/mdp
- MDp/mdp
- mDP/mdp
- MdP/mdp
- mdp/mdd
In absence of linkage, the genes would have assorted independently producing all the eight types of offspring in equal number. Hence the phenotype ratio would be 1:1:1:1:1:1:1:1.
If the genes are linked they will show the tendency to get inherited together and crossing over will not take place up to the expected degree. Hence fewer recombinants will be produced and more parental type offspring will be produced.
Answer:
D. Calcium ions.
Explanation:
Here we are talking about the mechanism of muscle contraction. The most accepted theory of muscle contraction is sliding filament theory. It was given by Huxley and Huxley. During the process actin filaments slides over myosin filament by forming cross bridges. The sequence of events are as follows:
a. An action potential propagates through the motor nerve and reach the nerve endings on the muscle fiber at neuro-muscular junction.
b. Neurotransmitter called acetylcholine is released by the nerve endings.
c. Acetylcholine binds to the receptors on muscle fiber and opens the gated channels which causes flow of Na+ ions into the muscle fiber.
d. This influx of sodium ions initiates an action potential in the muscle fiber which reaches the T- tubules or transverse tubules. Here it causes the sarcoplasmic reticulum to release large amounts of calcium ion.
e. Calcium ions are responsible for initiating the attractive forces between actin and myosin filaments. Cross bridges are formed, actin slides over myosin causing the contraction of muscle.
Answer:
The answer is letter D.
Explanation:
Tree D only . It is the only tree that is the most accurate.
The difference is Baxter was fermented