Genes and traits relationship help

Genes, Traits, and Proteins

genes and traits relationship help

and find homework help for other Science questions at eNotes. is the material that is located in the cell's nucleus that makes up the chromosomes and genes. Children inherit physical characteristics such as eye colour from their parents Related couples should seek advice from a clinical genetics service if their family The closer the genetic relationship between the parents, the greater the risk of . Find information, videos, and activities about DNA, genes, chromosomes, the Experiment with the forces involved and measure the relationship between the Description: This demonstration can be used to help students visualize DNA by.

Transcription and translation Transcription is the process in which information coded in DNA is transferred transcribed to ribonucleic acid RNA.

When transcription is initiated, part of the DNA double helix splits open and unwinds. The mRNA separates from the DNA, leaves the nucleus, and travels into the cell cytoplasm the part of the cell outside the nucleus—see Figure: There, the mRNA attaches to a ribosome, which is a tiny structure in the cell where protein synthesis occurs. Each molecule of tRNA brings one amino acid to be incorporated into the growing chain of protein, which is folded into a complex three-dimensional structure under the influence of nearby molecules called chaperone molecules.

These cells look and act differently and produce very different chemical substances. However, every cell is the descendant of a single fertilized egg cell and as such contains essentially the same DNA. Cells acquire their very different appearances and functions because different genes are expressed in different cells and at different times in the same cell.

The information about when a gene should be expressed is also coded in the DNA.

Genes, DNA and Chromosomes explained

Gene expression depends on the type of tissue, the age of the person, the presence of specific chemical signals, and numerous other factors and mechanisms. Knowledge of these other factors and mechanisms that control gene expression is growing rapidly, but many of these factors and mechanisms are still poorly understood.

genes and traits relationship help

The mechanisms by which genes control each other are very complicated. Genes have markers to indicate where transcription should begin and end. Various chemical substances such as histones in and around the DNA block or permit transcription. Replication Cells reproduce by splitting in two.

What Is a Gene?

Because each new cell requires a complete set of DNA molecules, the DNA molecules in the original cell must reproduce replicate themselves during cell division. Replication happens in a manner similar to transcription, except that the entire double-strand DNA molecule unwinds and splits in two. After splitting, bases on each strand bind to complementary bases A with T, and G with C floating nearby. When this process is complete, two identical double-strand DNA molecules exist.

There are also chemical mechanisms to repair DNA that was not copied properly. However, because of the billions of base pairs involved in, and the complexity of, the protein synthesis process, mistakes can happen.

Genes and genetics explained

Such mistakes can occur for numerous reasons including exposure to radiation, drugs, or viruses or for no apparent reason. Minor variations in DNA are very common and occur in most people. Most variations do not affect subsequent copies of the gene. Mistakes that are duplicated in subsequent copies are called mutations.

Inherited mutations are those that may be passed on to offspring. Mutations can be inherited only when they affect the reproductive cells sperm or egg. Mutations that do not affect reproductive cells affect the descendants of the mutated cell for example, becoming a cancer but are not passed on to offspring. Mutations may be unique to an individual or family, and most mutations are rare. Mutations may involve small or large segments of DNA.

Depending on its size and location, the mutation may have no apparent effect or it may alter the amino acid sequence in a protein or decrease the amount of protein produced. If the protein has a different amino acid sequence, it may function differently or not at all. An absent or nonfunctioning protein is often harmful or fatal.

For example, in phenylketonuriaa mutation results in the deficiency or absence of the enzyme phenylalanine hydroxylase. This deficiency allows the amino acid phenylalanine absorbed from the diet to accumulate in the body, ultimately causing severe intellectual disability.

genes and traits relationship help

In rare cases, a mutation introduces a change that is advantageous. For example, in the case of the sickle cell gene, when a person inherits two copies of the abnormal gene, the person will develop sickle cell disease. However, when a person inherits only one copy of the sickle cell gene called a carrierthe person develops some protection against malaria a blood infection. Although the protection against malaria can help a carrier survive, sickle cell disease in a person who has two copies of the gene causes symptoms and complications that may shorten life span.

Natural selection refers to the concept that mutations that impair survival in a given environment are less likely to be passed on to offspring and thus become less common in the populationwhereas mutations that improve survival progressively become more common.

Thus, beneficial mutations, although initially rare, eventually become common. The slow changes that occur over time caused by mutations and natural selection in an interbreeding population collectively are called evolution. Not all gene abnormalities are harmful.

genes and traits relationship help

For example, the gene that causes sickle cell disease also provides protection against malaria. Chromosomes A chromosome is made of a very long strand of DNA and contains many genes hundreds to thousands. The genes on each chromosome are arranged in a particular sequence, and each gene has a particular location on the chromosome called its locus.

Relationship Between DNA Bases Genes, Proteins and Traits | Sciencing

In addition to DNA, chromosomes contain other chemical components that influence gene function. Pairing Except for certain cells for example, sperm and egg cells or red blood cellsthe nucleus of every human cell contains 23 pairs of chromosomes, for a total of 46 chromosomes.

genes and traits relationship help

A gene is a basic unit of heredity in a living organism that normally resides in long strands of DNA called chromosomes. Genes are coded instructions that decide what the organism is like, how it behaves in its environment and how it survives. A gene consists of a long combination of four different nucleotide bases namely adenine, cytosine, guanine and thymine.

All living things depend on genes as they specify all proteins and functional RNA chains.

genes and traits relationship help

Proteins are large, complex molecules that play many critical roles in the body. They are necessary for building the structural components of the human body, such as muscles and organs. Proteins also determine how the organism looks, how well its body metabolises food or fights infection and sometimes even how it behaves. Proteins are chains of chemical building blocks called amino acids.

For example, the gene controlling red—green colour recognition is located on the X chromosome. A mother who carries the faulty gene causing red—green colour blindness on one of her X chromosome copies will have perfectly normal vision, as she still has a functioning gene copy for red—green colour recognition on her other X chromosome.

However, her sons have a 50 per cent chance of being colourblind. This is because there is a 50 per cent chance that they will inherit the X chromosome from their mother that contains the faulty gene. There is also a 50 per cent chance that they will inherit the X chromosome containing the correct copy of the gene and so will have normal vision. Genetic conditions To date, scientists have identified around 1, conditions caused directly or indirectly by changes in the genes.

Around half of all miscarriages are caused by changes in the total number of genes in the developing baby. Similarly, about half of the Australian population will be affected at some point in their life by an illness that is at least partly genetic in origin. The three ways in which genetic conditions can happen are: The variation in the gene that makes it faulty a mutation happens spontaneously in the formation of the egg or sperm, or at conception.

Uncovering the Relationship Between Genes and Proteins - ATA Scientific

The faulty gene is passed from parent to child and may directly cause a problem that affects the child at birth or later in life. The faulty gene is passed from parent to child and may cause a genetic susceptibility. Environmental factors, such as diet and exposure to chemicals, combine with this susceptibility to trigger the onset of the disorder.

It simply means you are at increased risk of developing the condition. Many conditions involving genetic susceptibility, such as some types of cancer, need to be triggered by environmental factors such as diet and lifestyle. For example, prolonged exposure to the sun is linked to melanoma. Avoiding such triggers means significantly reducing the risks. Genes and genetics — related parents Many cultures approve of marriage between relatives such as first cousins.

The aims of intermarrying are often to bolster family unity and keep wealth within the family. Consanguinity is often associated with factors such as: Related parents are more likely than unrelated parents to have children with health problems or genetic disorders.

This is because the two parents share one or more common ancestors and so carry some of the same genetic material. If both partners carry the same inherited altered mutated gene, their children are more likely to have a genetic disorder. Related couples should seek advice from a clinical genetics service if their family has a history of a genetic condition.

Autosomal recessive genetic disorders If two parents have a copy of the same altered gene, they may both pass their copy of this altered gene on to a child, so the child receives both altered copies.

As the child then does not have a normal, functioning copy of the gene, the child will develop the disorder. This is called autosomal recessive inheritance. Autosomal recessive genetic disorders are more likely if two parents are related, although they are still quite rare.

Examples of autosomal recessive genetic disorders include cystic fibrosis and phenylketonuria PKU. When both parents are carriers of the same altered gene, there is a one in four 25 per cent chance that each pregnancy will be affected. Other children of the same parents may also be affected or may be carriers, having only one copy of the altered gene. A child with only one copy of the altered gene will not be affected, as that child also has a normal copy of that gene — the same as the healthy parents.

Degrees of relationship Relatives are described by the closeness of their blood relationship. First-degree relatives share half their genetic information. Second-degree relatives share one-quarter of their genetic information.

The closer the genetic relationship between the parents, the greater the risk of birth defects for their children.