The cytoskeleton of a cell allows the cell to be flexible. Our human skeletons allow <em>us </em>to be flexible.
Answer:
The best description of the events occurring during Ana-phase I of meiosis:
c. Homologous chromosomes randomly separate and migrate to opposite poles.
Explanation:
Meiosis:
It is such type of cell division that occur in animals, plants resulting in four daughter cells and each of daughter cell have the half number of chromosomes from the parent cell.
- Anaphase is one of important phases of meiosis. The option a is incorrect as chromosomes go randomly to opposite poles.
- The option b is incorrect as all of chromosomes inherited from mother and father goes randomly to opposite poles.
- The option c is correct as it is the true description of anaphase I of meiosis.
- The option d is incorrect as the sister chromatids don't separate rather they remain joined.
Answer:
The correct answer is: A. Only the best-adapted animals in a population survive.
Explanation:
- Natural Selection is the process by which the individuals of a species which has the potential to sustain and survive in adverse or changing environment gets a survival advantage over those individuals which are unable to adapt themselves to altered environmental conditions.
- As the less potent individuals die in altered environmental conditions the adaptable individuals escapes competition with them for natural resources.
- Evolution causes species to alter their characteristics depending upon the demand of the conditions. These changes can vary, can be less or drastic.
- Animals pass all the newly adapted traits to the successive generations either as genetic traits or as acquired traits, as this is necessary for the offspring to survive in the altered environment.
- Natural selection is best defined as "the survival of the fittest".
Answer:
Atrioventricular valves.
Explanation:
Heart is the muscular organ of the body and acts as the pumping organ of the body. Human heart is not bigger than the fist and the human heart is divided into four chambers.
Heart murmur may be defined as the swishing sound that are made during the blood flow. This represent the heart problem. The bicuspid valve of heart is atrioventricular valve. The damage in the atrioventricular valve causes the heart murmuring.
Thus, the answer is atrioventricular valves.
