What are the four steps that explain how traits in a population change over time?
There are four principles at work in evolution—variation, inheritance, selection and time. These are considered the components of the evolutionary mechanism of natural selection.
Answer:
The correct answer is: Electrical impulses in the heart cause the muscles to contract.
Explanation:
The heart contracts thanks to a series of electrical impulses that travel through the muscles of this organ. The electrical impulse begins in the SA (sinoatrial) node and is transmitted to the muscles that conform the left and the right atria to produce their contraction which will make the atria pump the blood to the ventricles. When the electrical impulse reaches the AV node and then the Bundle of His, this information will transmit to both ventricles and will produce their contraction as well.
The only muscle tissue capable of stimulating their own contractions is the muscle in the heart, the myocardium, thanks to the existence of "pacemaker cells" that are located in the SA node.
The waves in the ECG represent the depolarization of the atria, depolarization of the ventricles, and repolarization of the ventricles.
Answer:
i hope this helps
Explanation:
the process of maintaining a stable internal environment, and breakdown of it ... how groups of organisms change over time (generations, longer periods of time) ... ability to maintain balance, grow, reproduce, and carry out other life functions.
I'm not sure what you mean by this but here is a diagram of a nephron!! Hope this helps?
Answer:
1. T
2. T
3. NP
4. F
5. F
Explanation:
In somatic cells, the cell cycle can be divided into 1-the interphase, 2-the mitotic phase or M phase, and 3-the G₀ phase. In turn, the interphase of the cell cycle can be divided into three phases: 1-the gap 1 (G1) phase or growth 1 phase, 2-the S phase (DNA replication or DNA synthesis), and 3-the gap 2 (G2) phase or growth 2 phase. During the G1 phase, the cell synthesizes key enzymes which are required during DNA replication (S phase) and cell division (M phase). Cytoplasmic factors are proteins and messenger RNAs (mRNAs) that control cell functions during the cell cycle. This cycle is modulated by proteins known as control factors, i.e., cyclins and cyclin-dependent kinases (Cdks) that work together to control the progression through different phases of the cell cycle. The transition from S to G2 occurs after DNA replication. This transition (S to G2) is controlled by a DNA damage checkpoint orchestrated by the ATM (Ataxia telangiectasia mutated) and ATR (Ataxia Telangiectasia and Rad3 related) kinases which are recruited to DNA damage sites. Moreover, the transition from G2 to M phase is mediated by the accumulation of mitotic inducers, which lead to an increase in the activity of mitotic kinase and finally trigger mitotic entry.
