Deck 1: Overview of Genetics

Question 1

Pick any example of a genetic technology and describe how it has directly affected your life.

Answer 1

The genetics is a broad science that explains about the inheritance patterns, form the lower organisms to higher organisms. It will account for the development of human race and their sustainability.
The every organism have different type of genetic nature, their genetic nature is determined by the genes present on their chromosomes. The genes directly reflect the various actions like behavioural changes, metabolic patterns and morphological changes extra.
The genes are expressed at the molecular. The expressible units of the genes are nothing but proteins. These proteins are working horses of a cell; they might be an enzyme or a structural protein that supports growth of that particular organism. All these proteins involved in the regulation of metabolic pathways and to maintain the homeostasis at complete organism level.
A group of organisms, which have the similar morphology, are called species and the group of species is called a population. The refinement of the genes through the evolution results the development of various new species from the already existed organisms.
In the 20 th century the genetic technology is highly developed, due to the development of the various instrumental technologies and the development of Recombinant DNA technology.
The recombinant DNA technology is deals with the direct gene manipulation and insertion of the new genes in other organism's genome. This results either inhibition of a character or the expression of new characters on that particular organism.
The best example of the genetic technology is Pseudomonas putida. This organism contains the genes responsible for the biodegradation of oils on sea bed. The oil layers on the sea bed, which does not allow the passage of gases into the sea results due to the oil spillage, form the ships and some other domestic sources. This oil bed is mainly responsible for the death of various marine organisms, but by the application of Pseudomonas putida on these oil spills they completely clear the oil zones.
Therefore, this technology is highly used for the mankind and decreasing the pollution levels on the environment.

Question 2

What is a genetic cross

Answer 2

The genetic cross is a method, used in the transmission genetics. This method, explains about how the genes or characters, which are transmitted from one generation to other generation.
The cross between the two individuals, having different types of characters yields the progeny with new characters. Some, of the progeny have the similar genetic makeup like their parents or some, got different genetic makeup unlike their parents.
The genetic cross is existed in different forms they are:
• Monohybrid cross (the cross between the individuals by considering single character or different alleles at single genetic locus).
• Di hybrid cross (the cross between the individuals by considering two characters or different alleles at two genetic loci).
• Tri hybrid cross (the cross between the individuals by considering three characters or different alleles at three genetic loci).
For example the monohybrid cross is as follows:
The monohybrid cross is explained as the cross between the individuals, by considering single character or different alleles at single genetic locus.
The monohybrid cross by taking single character the height of plant. Here, one tall plant having Tall character is crossed with the other plant having Dwarf character . In the first generation the obtained plant have Tall character, but heterozygote in nature. Upon formation of gametes, the cross between the gametes, leads to the production of three tall plants, among the three one is homozygote, and two are heterozygote in nature.
The F 2 genotypic ratio is , and the phenotypic ratio is .

Question 3

At the molecular level, what is a gene Where are genes located

Answer 3

The Gene is defined as is a segment of DNA that produces a functional product. Here, the functional product is nothing, but a protein. The proteins derived from the information provided form the genes. The derived proteins are polymeric compounds have amino acids as their monomeric units.
The genes are technically or classically defined as a unit of heredity. The genes are located on chromosomes. The chromosomes are having different types of genes on them. Each gene is responsible for the production of a single protein molecule, these protein molecule are expressed as a character on an individual organism.
At the molecular level the genes are linear polymeric chains that are composed of nucleotides as their monomeric molecules. Every organism has four different types of nucleotides they are: Adenine (A), Guanine (G), Thiamine (T), and cytosine (C). These nucleotides are polymerized into DNA molecule by the process called DNA polymerization.
This long DNA molecule is have some special regions, they are:
• A promoter sequence
• Enhancer sequences
• Terminator sequence
The promoter sequence is the initial sequence that contains "consensus sequences," these sequences are never altered in any organism. During the transcription mechanism, the RNA polymerase enzyme binds on promoter sequence.
The Enhancer sequences are involved in the enhancement of the transcription process by the RNA polymerase.
The Terminator sequence is involved in the termination of the transcription process.

Question 4

The technique known as DNA sequencing (described in Chapter 20) enables researchers to determine the DNA sequence of genes. Would this technique be used primarily by transmission geneticists, molecular geneticists, or population geneticists

Question 5

Most genes encode proteins. Explain how the structure and function of proteins produce an organism's traits.

Question 6

Figure 1.5 shows a micrograph of chromosomes from a normal human cell. If you performed this type of experiment using cells from a person with Down syndrome, what would you expect to see
FIGURE 1.5 A micrograph of the 46 chromosomes found in a cell from a human male.

Question 7

Briefly explain how gene expression occurs at the molecular level.

Question 8

Many organisms are studied by geneticists. Of the following species, do you think it would be more likely for them to be studied by a transmission geneticist, a molecular geneticist, or a population geneticist Explain your answer. Note: More than one answer may be possible.
A. Dogs
B. E. coli
C. Fruit flies
D. Leopards
E. Corn

Question 9

A human gene called the -globin gene encodes a polypeptide that functions as a subunit of the protein known as hemoglobin. Hemoglobin is found within red blood cells; it carries oxygen. In human populations, the -globin gene can be found as the common allele called the Hb A allele, but it can also be found as the Hb S allele. Individuals who have two copies of the Hb S allele have the disease called sickle cell disease. Are the following examples a description of genetics at the molecular, cellular, organism, or population level
A. The Hb S allele encodes a polypeptide that functions slightly differently from the polypeptide encoded by the Hb A allele.
B. If an individual has two copies of the Hb S allele, that person's red blood cells take on a sickle shape.
C. Individuals who have two copies of the Hb A allele do not have sickle cell disease, but they are not resistant to malaria. People who have one Hb A allele and one Hb S allele do not have sickle cell disease, and they are resistant to malaria. People who have two copies of the Hb S allele have sickle cell disease, and this disease may significantly shorten their lives.
D. Individuals with sickle cell disease have anemia because their red blood cells are easily destroyed by the body.

Question 10

Pick any trait you like in any species of wild plant or animal. The trait must somehow vary among different members of the species (see Figure 1.7). Note: When picking a trait to answer this question, do not pick the trait of wing color in butterflies.
A. Discuss all of the background information that you already have (from personal observations) regarding this trait.
B. Propose a hypothesis that would explain the genetic variation within the species. For example, in the case of the butterflies, your hypothesis might be that the dark butterflies survive better in dark forests, and the light butterflies survive better in sunlit fields.
C. Describe the experimental steps you would follow to test your hypothesis.
D. Describe the possible data you might collect.
E. Interpret your data.
FIGURE 1.7 The relationship between genes and traits at the (a) molecular, (b) cellular, (c) organism, and (d) population levels.

Question 11

What is meant by the term "genetic variation" Give two examples of genetic variation not discussed in Chapter 1. What causes genetic variation at the molecular level

Question 12

What is the cause of Down syndrome

Question 13

Your textbook describes how the trait of phenylketonuria (PKU) is greatly influenced by the environment. Pick a trait in your favorite plant and explain how genetics and the environment may play important roles.

Question 14

What is meant by the term "diploid" Which cells of the human body are diploid, and which cells are not

Question 15

What is a DNA sequence

Question 16

What is the genetic code

Question 17

Explain the relationships between the following pairs of genetic terms:
A. Gene and trait
B. Gene and chromosome
C. Allele and gene
D. DNA sequence and amino acid sequence

Question 18

With regard to biological evolution, which of the following statements is incorrect Explain why.
A. During its lifetime, an animal evolves to become better adapted to its environment.
B. The process of biological evolution has produced species that are better adapted to their environments.
C. When an animal is better adapted to its environment, the process of natural selection makes it more likely for that animal to reproduce.

Question 19

What are the primary interests of researchers working in the following fields of genetics
A. Transmission genetics
B. Molecular genetics
C. Population genetics