Answer:
In a population, a specific gene has two alleles, 'A' and 'a.' Individuals with
genotype 'aa' die in early childhood. Individuals with genotype 'Aa' have a
higher rate of surviving and reproducing than individuals with genotype 'AA.'
This phenomenon is called survival of the fittest, Darwins law which entails the fittest organisms survives while the ones that could not would go into extinction
Explanation:
Answer:
Neither evolution is not real.
Explanation:
God created everything on earth in space and everything beyond what we can see feel or hear.
Answer:
1. sperm cells: cell has a flagellum for movement
2. smooth muscle: cells have an elongated shape (tapered at each end)
3. Squamous epithelium: cells are close together
4. Human red blood cells: cells are circular
5. Squamous epithelium cells are thin and flat, with irregular borders
6. Human red blood cells: cells are anucleate (without a nucleus)
7. smooth muscle: longest cell
Explanation:
- <em>Sperm cells</em>: Active and morphologically specialized cells. They characterize as having an elliptic head mostly occupied by the nucleus, and a tail of about 55 micrometers that moves impulsed by a motor dynein protein that uses ATP energy.
- Smooth muscle cells: Fusiform cells. Long and tapered at the extremes. Located in organs and viscera, and in vessel walls, where involuntary maintained slow contractions are needed. Although they are the longest cells, their length depends on the organ where they are located. They might reach up to 500 microns.
- Squamous epithelium cells: The wide and length of the cells supere their height. Some of them suffer a process of keratinization from being exposed to dehydration and touch.
- Red blood cells: Red blood cells or erythrocytes are biconcave disks-shaped, with no nucleus, and very small. These are flexible cells that might move along in the smallest capillaries. Hemoglobin provides the typical red color. The red blood cell size and number vary among species.
Answer:
The correct answer would be Atria push blood into the ventricles and Ventricles push blood out of the heart.
In humans, four chambered heart is present with two atria and two ventricles.
Deoxygenated blood from all over the body is passed into the right atrium through vena cava (superior and inferior).
Simultaneously, oxygenated blood from the lungs is passed into the left atrium of the heart with the help of pulmonary vein.
Both the atria contract at the same time to drain their blood into respective ventricles.
The ventricles undergo relaxation while receiving blood.
The valves present between the atria and ventricles (tricuspid and bicuspid valve) ensures that the blood flows in one way direction only. They shut down as the ventricles contract and produce the sound "lub".
The ventricles contract simultaneously to pump blood out of the heart. The right ventricle pumps deoxygenated blood into pulmonary artery which takes the blood to the lungs for oxygenation.
The left ventricle passes the oxygenated blood through aorta to all the parts of the body.
The pulmonary and aortic valves prevent the back flow of blood and shut at the same time which creates second sound called as "dub".
