We'll make the alleles: Cc.
C is a healthy parent, and c is the cystic fibrosis (recessive).
If you make a punnett square and the parents are both Cc (healthy), then you would get CC, Cc, Cc, and cc. That cc is a 25% chance that the offspring will have that, which means there is a 25% chance the child will have cystic fibrosis.
Two healthy parents can have a child with cystic fibrosis if both the parents have the dominant allele and recessive allele, if both the parents have heterozygous alleles.
Each myofibril is attached at either end of the muscle fiber, when sarcomeres shorten, the muscle fiber Shortens
Mechanism :
Myofibrils are components of the animal skeletal muscles that are made up of sacromeres. They perform the muscular contraction and relaxation via the sliding filament model.
To produce motion, A cross-bridge forms between actin and the myosin heads triggering shortening of the sacromere. This shortening of the sacromere results in the contraction of the muscle fibers, which the net effect can be seen to be a shortening of the fibers.
To learn more about myofibril refer to : brainly.com/question/15461128
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A. Cell membrane would be the answer.
