Genetic variation is a measure of the genetic differences that exist within a population. The genetic variation of an entire species is often called genetic diversity. Genetic variations are the differences in DNA segments or genes between individuals and each variation of a gene is called an allele.For example, a population with many different alleles at a single chromosome locus has a high amount of genetic variation. Genetic variation is essential for natural selection because natural selection can only increase or decrease frequency of alleles that already exist in the population.
Answer:
Respiration is the process where oxygen is taken in and carbon dioxide is exhaled out and combustion means the burning of substances in the presence of oxygen
1. Solar system
2. sun
3. planet
4.orbit
5.moon
6.Asteroid
7.Comet
8.gas giant
9.dwarf planet
<u>Cross-sectional </u>research method
Explanation:
The cross-section research design is most widely used in healthcare based researches. It is type of descriptive research based on observational studies.
This research is usually done on a group of people and provides both qualitative (descriptive interpretations) and quantitative (statistical interferences) details.
This research is not a relational type of research and hence cannot be used to study, relate or compare about individual changes. The experiences, values, changes observed in individual cases are not taken into consideration.
For example, it is used to study a disease like cancer in a certain group or a population-based on variables like different sex, age religion, ethnicities, location etc of various people. It is not used to study about cancer in an individual person.
It is also not the causal type and cannot be used for cause and effect type of researches. Manipulation of variables is not possible with this research design.