Natural selection is the process by which individuals with characteristics that are advantageous for reproduction in a specific environment leave more offspring in the next generation, thereby increasing the proportion of their genes in the population gene pool over time. Natural selection is the principal mechanism of evolutionary change, and is the most important idea in all biology. Natural selection, the unifying concept of life, was first proposed by Charles Darwin, and represents his single greatest contribution to science.
Natural selection occurs in any reproducing population faced with a changing or variable environment. The environment includes not only physical factors such as climate or terrain, but also living factors such as predators, prey, and other members of a population.
Mechanism of Natural Selection
The mechanism of natural selection depends on several phenomena:
• Heredity: Offspring inherit their traits from their parents, in the form of genes.
• Heritable individual variation: Members of a population have slight differences among them, whether in height, eyesight acuity, beak shape, rate of egg production, or other traits that may affect survival and reproduction. If a trait has a genetic basis, it can be passed on to offspring.
• Overproduction of offspring: In any given generation, populations tend to create more progeny than can survive to reproductive age.
• Competition for resources: Because of excess population, individuals must compete for food, nesting sites, mates, or other resources that affect their ability to successfully reproduce.
Given all these factors, natural selection unavoidably occurs. Those members of a population that reproduce the most will, by definition, leave more offspring for the next generation. These offspring inherit their parents' traits, and are therefore also likely to succeed in competition for resources (assuming the environment continues to pose the same challenges as those faced by parents). Over several generations, the proportion of offspring in a population that are descended from the successful ancestor

Uloborid spider eggs and spiderlings. In any given generation, populations tend to create more offspring than can survive to reproductive age.
increases, and traits that made the ancestor successful therefore also increase in frequency. Natural selection leads to adaptation, in which an organism's traits conform to the environment's conditions for existence.
I think its the first one
The correct option is C.
Lantana is a tropical evergreen shrub which is usually cultivated as ornamental flowers. It is a plant that threatening livestock especially in Australia. The signs of lantana poisoning in livestock include: excessive skin sensitivity to sunlight, liver damage, yellow coloration of the white part of the eyes, reddening of the eyes, swelling of the ears, etc.
If the poisoning case is severe, the animal death will occur between two to four days, but generally, untreated animals usually die within one to three weeks.
Answer:
The correct answer will be option-B
Explanation:
Meiosis is a way of cell division used by the organism to produce a large number of cells from a few parent cells. This is used to make the gametes of the body.
Meiosis produces four daughter cells from a single parent cell in two stages that is meiosis I and II. Each stage proceeds in four phases- prophase, metaphase, anaphase and telophase.
The reduction division of the chromosomes or the ploidy number takes place during anaphase I of meiosis I and not prophase I which is the initial phase of the division. Therefore, during prophase I the chromosome number of the cell remains the same.
Thus, Option-B is the correct answer.
