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:
C. All fossils contain intact DNA that can be sequenced.
Explanation:
Fossils are the impression, trace or preserved remains of once-living thing from past thousands of years such as bones, exoskeletons, objects preserved in amber, and stone imprints of animals or microbes.
Fossils provide evidence about seevral characteristics and features of extinct organism such as evolutionary relationship between organisms and transitional forms between groups of organisms. but all the fossil do not provide evidence about the intact DNA that can be sequenced because some fossils carry DNA rumnants which do not have the ability to get sequenced.
Hence, the correct option is C.
The answer is true letter a
<h2>Answer 1 with Explanation</h2>
Homozygous dominant- It can be an organism if it carries two copies of the same dominant allele as homozygous which clearly means that the organism has a pair of models that is the corresponding allele for a gene. This gene originally belongs to a particular gene that has same alleles on both homologous chromosomes. It is assigned to by capital (XX) in the subjective terminology.
<h2>Answer 2 with Explanation</h2>
Heterozygous dominant is an organism that carries two different alleles of a gene. Though this is originally is referred to as (Tt). Heterozygous means that an organism has two different varieties of the gene within the system of dominant, the protein each makes is slightly different from one another and the organism has both tall and short versions within the dominant.
<h2>Answer 3 with Explanation</h2>
Homozygous recessive is described as an organism that carries two copies of the same recessive allele in the living organisms while they are in process of growth. A recessive gene is one that has to be homozygous to have an effect on the plant's or animal's traits that is naturally in process. This process of homozygous is is referred to by the lower case (xx).
