What are genes?
Genes carry the knowledge that determines our traits, which are features or characteristics that we inherit from our parents. Each cell within the physical structure contains approximately 25,000 to 35,000 genes.
If both of your parents have blue eyes, you may inherit the trait for blue eyes from them or if your mom has brown hair, you would possibly have brown too because you inherited the trait for brown hair. Genes are in humans but also animals and even plants.
Where are these important genes?
Genes are so small that you simply cannot see them but they're found inside cells in structures called chromosomes. The body is formed of billions of cells which are very small units that everyone living things are made of.
Chromosomes are found in pairs and there are hundreds and sometimes thousands of genes in only one chromosome. The chromosomes and genes are made from DNA.
Most cells have one nucleus which is a small structure inside the cell which acts just like the brain of the cell; it tells a part of the cell what to do. The nucleus is ready to do this because it contains our chromosomes and genes.
In humans, a nucleus contains 46 individual chromosomes or 23 pairs of chromosomes half these chromosomes come from the parent and therefore the other half come from the female parent. Under the microscope, we are able to see that chromosomes are available in different lengths and striping patterns. after they are lined up by size and similar striping pattern, the primary twenty-two of the pairs these are called autosomes; the ultimate pair of chromosomes are called sex chromosomes, X and Y. The sex chromosomes determine whether you are a boy or a girl: females have two X chromosomes while males have one X and one Y.
The amount of chromosomes varies from species to species as an example fruit flies have only 8 chromosomes or 4 pairs of chromosomes.
How do genes affect human behaviour?
The relationship between your genes and behaviour can change over time as you've got new experiences. In some situations, genes play a bigger role in determining your behaviour; in other situations, environment plays a bigger role in influencing your behaviour. If you had an entire different set of experiences over your lifetime your genes are also expressed in several ways, and you'll behave differently than you are doing now.
Environmental factors like light and temperature are shown to induce certain changes in genetic expression; additionally, exposure to drugs and chemicals can significantly affect how genes are expressed. People often inherit sensitivity to the results of varied environmental risk factors, and different individuals is also differently full of exposure to the identical environment in medically significant ways. for instance, sunlight exposure features a much stronger influence on carcinoma risk in fair-skinned humans than in individuals with an inherited tendency for darker skin. the colour of a person’s skin is essentially genetic, but the influence of the environment will affect these genes in several ways.
Gene-environment correlations will be explained in 3 particular ways—passive, evocative, or active.
Passive Gene-Environment Correlations
In passive gene-environment correlation, there's an association between a person’s genetic makeup and therefore the environment during which they're raised. In other words, the person’s environment, particularly within the case of young people, is essentially determined by the parent’s genetic characteristics.
Evocative Gene-Environment Correlations
Evocative gene-environment correlation happens when an individual’s heritable behaviour evokes an environmental response. as an example, the association between marital conflict and depression may reflect the tensions that arise when engaging with a depressed spouse instead of a causal effect of marital conflict on risk for depression.
Active Gene-Environment Correlations
In active gene-environment correlation, the person’s genetic makeup may lead them to pick particular environments. as an example, a coward is probably going to settle on quiet activities and fewer boisterous environments than an extroverted individual. He or she is also more likely to spend time at the library than at a dance club.
Adoption and Twin Studies within the Nature vs. Nurture Debate
Adoption and twin studies can help be of the influence of genes and therefore the environment. Studies of adult twins are wont to investigate which traits are heritable. Identical twins share the identical genotype, meaning their genetic makeup is that the same. Twins raised apart tend to be similar in intelligence and, in some cases, life events and circumstance, when studied years later, even when raised separately.
However, researchers have discovered that the phenotype (the observable expression of a gene) of identical twins grows apart as they age. In adoption studies, identical twins raised by different families can give insight into the nature-versus-nurture debate. Since the kid is being raised by parents who are genetically different from their biological parents, the influence of the environment shows in how similar the kid is their adoptive parents or siblings. Adoption studies make a powerful case for the influence of environment, whereas twin studies make a powerful case for genetic influence.
Behavioural Genetics
Behavioural genetics studies heritability of behavioural traits, and it overlaps with genetics, psychology, and therefore the scientific study of human and animal behaviour. Genetics plays an oversized role in when and the way learning, growing, and development occurs. as an example, although environment has an impact on the walking behaviour of infants and toddlers, children are unable to steer in any respect before an age that's predetermined by their genome. However, while the genetic makeup of a baby determines the age range for when he or she is going to begin walking, environmental influences determine how early or late within that range the event will actually occur.
Classical Genetics
Classical, or Mendelian, genetics examines how genes are passed from one generation to the subsequent, as well as how the presence or absence of a gene can be determined via sexual reproduction. Gregor Mendel is thought as the father of the field of genetics, and his work with plant hybridization (specifically pea plants) demonstrated that certain traits follow particular patterns. This is referred to as the law of Mendelian inheritance.
Genes can be manipulated by selective breeding, which can have an enormous impact on behaviour. For example, some dogs are bred specifically to be obedient, like golden retrievers; others are bred to be protective, like German shepherds. In another example, Seymour Benzer discovered he could breed certain fruit flies with others to form distinct behavioural characteristics and change their circadian rhythms.