Monohybrid Crosses Reveal

F1 plants display the phenotype of only one parent, they must inherit genetic factors from both parents.

When dominant and recessive alleles are present together, the recessive allele is masked, or suppressed.

TLS Online TPP Program

#Id: 8398

#Unit 2. Cellular Organization

In the presence of ATP and Ca+2 , the myosin heads extending from the thick

filaments walk toward the (+) ends of the thin filaments.

TLS Online TPP Program

#Id: 8399

#Unit 2. Cellular Organization

The structure of the sarcomere is maintained by a number of accessory proteins: 

1. CapZ 

2.Tropomodulin

3.Titin 

4.Nebulin

TLS Online TPP Program

#Id: 8400

#Unit 2. Cellular Organization

In skeletal muscle cells, 

a low cytosolic Ca+2 level is maintained by a unique Ca+2 ATPase that continually pumps Ca+2 ions from

the cytosol containing the myofibrils into the SR, establishes a reservoir of Ca+2 in the SR.

TLS Online TPP Program

#Id: 8402

#Unit 2. Cellular Organization

The arrival of a nerve impulse at a neuromuscular junction triggers an action potential in sarcolemma.

TLS Online TPP Program

#Id: 8403

#Unit 2. Cellular Organization

AP activates a  voltage gated Ca2+ channel in the T-tubule membrane, it triggers the opening of a Ca2+ -release channel in the closely associated SR membrane

TLS Online TPP Program

#Id: 8404

#Unit 2. Cellular Organization

The increase in Ca2+ concentration is transient because the Ca2+ is rapidly pumped back into the SR by an abundant, Ca2+ ATPase.