Answer:
1. False
2. True
3. True
4. False
Explanation:
In mammals, the contraction of the heart muscle is caused by pacemaker cells localized within the sinoatrial (SA) node. These cells rhythmically generate slow electrically-induced action potentials due to their slow rate of depolarization. The pacemaker cells generate the action potentials that propagate through the heart and trigger the contraction of myocyte cells (i.e., myocytes simply conduct the action potential waves). The slow depolarization of pacemaker cells occurs during diastole, i.e., during the period of relaxation of the heart muscle.
Answer:
True
Explanation:
An atom is stable because of a balanced nucleus that does not contain surplus energy. If the forces between the protons and the neutrons in the nucleus are unbalanced, then the atom is unstable. Stable atoms retain their form for ever, while unstable atoms undergo radioactive decay.
Answer:
There can be many different limiting factors at work in a single habitat, and the same limiting factors can affect the populations of both plant and animal species. Ultimately, limiting factors determine a habitat's carrying capacity, which is the maximum size of the population it can support.
Explanation:
Answer:
By difference in there ribosomal RNA sequence
Explanation:
Both bacteria and archaea lack membrane-bound nucleus and earlier both are considered in the same categories. Carl Woese was the scientist who discovered that bacteria and archaea are not similar.
Carl Woese and his lab members checked the ribosomal RNA in some archaeans and concluded that the archaeans are more closely related to eukaryotes than bacteria. After the study on archean Carl Woese classified the prokaryotes into two domains i.e., bacteria and archaea.
Therefore by difference in the ribosomal RNA sequence archaeons first distinguished from other prokaryotes.
