Answer:
A punnet square can be described as a diagram which is made to check the outcomes of a cross.
To check the probability of the offsprings of a cross between homozygous dominant thumb shape parent with a homozygous recessive thumb shape parent, let's draw a punnet square:
t t
T Tt Tt
T Tt Tt
The results of the punnet square depict that:
Genotype: All of the offsprings will be heterozygous for the thumb shape trait. Tt will be the genotype.
Phenotype: All of the offsprings will show the thumb shape like the thumb shape of the dominant parent.
Mitotic spindles are microtubule-based structures that separate chromosomes during mitosis. So the cell would lack structure.
Answer:
D
Explanation:
Lymphocytes are the second line of defence
First line of defence indiscriminately defends against all pathogens unlike secondary response which is targeted. First line of defence refers to the external body components like skin, secretions from the body in the alimentary canel
Mucus traps pathogens. Stomach acid kills pathogens
Answer and Explanation:
In rest, attraction strengths between myosin and actin filaments are inhibited by the tropomyosin. When the muscle fiber membrane depolarizes, the action potential caused by this depolarization enters the t-tubules depolarizing the inner portion of the muscle fiber. This activates calcium channels in the T tubules membrane and releases calcium into the sarcolemma. At this point, tropomyosin is obstructing binding sites for myosin on the thin filament. When calcium binds to the troponin C, the troponin T alters the tropomyosin by moving it and then unblocks the binding sites. Myosin heads bind to the uncovered actin-binding sites forming cross-bridges, and while doing it ATP is transformed into ADP and inorganic phosphate which is released. Myofilaments slide impulsed by chemical energy collected in myosin heads, producing a power stroke. The power stroke initiates when the myosin cross-bridge binds to actin. As they slide, ADP molecules are released. A new ATP links to myosin heads and breaks the bindings to the actin filament. Then ATP splits into ADP and phosphate, and the energy produced is accumulated in the myosin heads, which starts a new binding cycle to actin. Z-bands are then pulled toward each other, thus shortening the sarcomere and the I-band, and producing muscle fiber contraction.
Answer:
Change occur in the genetic makeup.
Explanation:
Brian means that the change occur in the genetic makeup of the mitochondrial DNA that change the structure as well as the function ability of mitochondria which is responsible for the generation of energy for the cell. The mitochondrial DNA are passed from mother to offspring through the egg cell. He signify mitochondrial DNA because the change occur only in the mitochondrial DNA not in the whole organism's DNA.