Muscles are required in breathing, talking, running, walking, and any body movement. Actin and myosins are protein filaments present in muscle cells that help to contract and relax or change the shape of muscles. Muscles are responsible for the movement or motion of organisms. Joints are the connection between two or more bones. Most joints are mobile.
Muscle strength is determined by several factors. Some of those are the physical shape, size, and innervation of the muscles.
Weak contraction
- Potassium accumulates in the sarcoplasm.
- Contracted lower sarcoplasm pH.
- Begin contraction with muscle already 50%.
- The circular arrangement of muscle fascicles.
Stronger contraction
- Increase in muscle belly circumference.
- A lesser proportion of motor neurons to muscle fibers.
- Increased recruitment.
- Increased stimulus frequency.
Answer:
C. Organisms are now divided into three kingdoms.
Explanation:
In the early 1860s, a German scientist named Ernst Haeckel suggested using a three kingdom system of classification. Haeckel's three kingdoms were Animalia, Plantae, and Protista.
Answer:
2) CAG - TTC - ACG mutates to CAG - TTC - ACC - ACG
Explanation:
Insertions are mutations in which extra base pairs are inserted into a new place in the DNA. The number of base pairs inserted can range from one to thousands!
In option no. 1: We see that there is not addition of a single or more than one base, but the new base sequence is different from the original sequence at three places i.e: TTA - CAC - G
In option no. 2: The insertion of three bases ACC has been made exactly after TTC, the whole sequence and arrangement of bases remain same except this insertion.
In option no. 3: The first base of the sequence T is replaced with A, and all other sequence is same. This type of mutation is called substitution in which one base is replaced by other.
In option no. 4: The last base of the sequence C is deleted, and is not present in new sequence. This type of mutation is called deletion in which a base is removed from the sequence.
Conclusion: Therefore, the best option is 2, in which whole codon is inserted in the DNA base sequence.
Answer:
These crops where improved with technology, production of high-yielding variety, and improve farm practices. All these ensured the crops of green revolution had increase yield.
Explanation:
Through genetic engineering, high-yielding variety of cereals e.g wheat, maize, rice, were genetically engineered so that certain features which enhanced increased productivity were selected for.
Use of fertilization, the adoption of mechanization,good cropping and farming system are other factors which enhanced yield of these crops. Specifically, these crops were modified to enhance their Nitrogen uptake, which promotes rapid growths.
I think Mitosis precedes cytokinesis
-hope this helps :3