At that time, plate tectonic movements shoved all of the continents into one big super continent. After that time, plate movements started to break up this super continent until the continents eventually reached their present configuration.
Answer:A. The release of calcium ions causes myosin and actin to attach to each other.
The contraction of skeletal muscles takes place by induction of a nerve impulse, which produces a movement and the interaction of the filaments containing proteins named as actin and myosin. This interaction of filaments is regulated by proteins called tropomyosin and troponin present on the actin filaments. The motor nerve causes the depolarization of the muscle membrane sarcolemma. This triggers the sarcoplasmic reticulum to release calcium ions. This calcium binds to troponin and thus allows the tropomyosine strand on the actin filament to displace so that the part of the actin where myosine head needs to be attached remain uncovered. Binding of the actin myosine filament results in contraction.
Hence, the release of calcium ions causes myosin and actin to attach to each other causes muscle contraction.
Answer:
DNA is the genetic information used to make proteins, and it contains the hereditary traits of organisms. There are two types of DNA: mitochondrial DNA, which you can only get from your mother, and nuclear DNA, which is a combination of both your ancestors' DNA.
Explanation:
The answer is; B
Meristem cells are totipotent meaning they can differentiate to any type of plant cells. Therefore they can produce a variety of plant type depending on epigenetic. However, tissue culture is derived from already differentiated cells. Therefore these cells are already determined and can only produce cell type of that plant from which they were derived.
Answer:the fitness of an organism is the ability to survive and reproduce
Explanation:
