Answer:
- Radial symmetry is advantageous because sessile animals can "sit down", take food, or sense harmful environmental conditions from different directions.
- Bilateral symmetry allows motile animals to move straight forward.
- The major evolutionary advantages of bilateral symmetry include cephalization, the formation of a head and tail area and a more directional motion.
Explanation:
Radial symmetry is advantageous for sessile organisms since it enables the uniform distribution of the sensory receptors around the body. In consequence, sessile organisms can react to environmental stimuli from every direction. On the other hand, bilateral symmetry allows motile organisms the arrangement of a specialized nervous system from the anterior end of the organism (i.e., the 'head'). Moreover, another important advantage of bilateral symmetry is the ability to equalize environmental pressures on both sides of the body, thereby enabling a rectilinear motion.
Tha main components in blood are the plasma, red blood cells, white blood cells, and blood platelets.
Plasma is like the main component that makes up most of the blood. It has a light yellow color and it carries many substances including nutrients, waste, hormones and more.
Red blood cells are the reason why blood is red in color. They have a hemoglobin inside them which can help carry oxygen for the tissues and organs. In order to maximize the oxygen carrying capacity, they don't have a nucleus.
White blood cells can be divided into phagocytes and lymphocytes. Their main function is to protect us from diseases. Phahocytes and engulf and digest bacteria, while lymphocytes can produce antibodies.
Blood platelets can cause blood clotting which can stop us from bleeding forever. They're not cells, but just fragments of cells. They also don't have nucleus since they're not complete cells.
The size of the algal size will increase or swell when a student removes an algal cell from its marine environment and puts it into a sample of freshwater.
Tonicity refers to the concentration of a solution compared to another solution. A solution is said to be hypertonic, if it has a greater concentration of solutes than the other solution. A solution is said to be hypotonic, if it has a lower concentration of solutes than the other solution. A solution is said to be isotonic, if it has the same concentration of solutes as of the other solution.
In a marine environment, the algal cells are said to be hypertonic with a higher concentration of the solutes than the freshwater. When such a cell is placed in freshwater with hypotonic environment, the concentration of solutes in the cell is higher than the external environment. In other words, it has lesser water molecules in it. As a result, osmosis occurs which is the movement of water molecules from a region of its higher concentration to a region of its lower concentration through a semipermeable membrane and water enters the cell from the freshwater. Thus, increasing the size of the algal cell or the algal cell swells.
The phenotype is - 75 % red and 25 %brown.
The genotype is hRhR - 25%
hBkhR - 50%
hBrhBk - 25%.
<h3><u>Explanation:</u></h3>
The cross given here is a simple dominant - recessive relationship between the three types of alleles of hair colour. The genes of this characteristics are present in autosomes, so will be segregated equally among all the sexes of the offsprings.
Now the genotype of auburn and red with black mother is given. So during gametogenesis, the gametes from the parents will be
Father - hBr and hR
Mother - hBk and hR
So, the probable combinations are hBrhBk, hBrhR and hBkhR.
The frequency of the combinations are 25%, 25% and 50% respectively.
The phenotypic ratio will be red : brown as 3:1.
Answer:
__ It implies that prokaryotes existed before eukaryotes, and
__ It implies that eukaryotes evolved from prokaryotes.
Explanation:
The prefix pro- can mean "before". By using the term prokaryote one can tend to think that procaryotes preceded eukaryotes.
Preceed as existed before them, or as an evolutionary point of view.
