Ok so theirs this thing called asking your teacher for help especially when it’s such an easy question
Answer:
The Z lines and H- zone shortens during the muscle contraction.
Explanation:
Sarcomere is the area between the two Z lines. The Z- lines are present in the centre of I - band and H - zone is present in the A - band. The actin filaments which are thin filaments present in I- band and contracts, slide over the myosin filament during contraction.
The I - band, H- zones are became shortens as they are thin than the A- band. It is anisotropic band having thick myosin filaments. They are not flexible and remain in its constant shape during the muscle contraction.
After the muscle contraction, the A- band and the H- zone comes to their original shape. In other words, the sarcomere shortens and comes back during muscle contraction, and relaxation.
Answer:
In mendelian inheritance, the alleles for a gene show normal dominant-recessive relationship. Chromosomes also show crossover due to which new random combination of traits is possible in the offspring. This crossover takes place between homologous chromosomes during meiosis I.
Organellar DNA like the ones present in mitochondria and chloroplast do not follow mendelian inheritance because unlike nuclear chromosomes they do not have cross over events. There is no orderly segregation of alleles during meiosis. Traits controlled by them are usually inherited as it is and usually it is from the maternal parent because paternal gamete like sperm does not contain mitochondria.
nothing is there what are you talking about
I am sorry I can only answer 7 for you.
Hope it helps
7= By replacing the neurons lost from a injury with new cells.
