Bacterial resistance is a common issue encountered in various infections. Scientists have attributed this phenomenon to the overuse of anti-bacterial sanitizers and prescription antibiotics. Two groups of researchers performed studies to test bacterial resistance.

Study 1

Researchers in this study state that bacterial resistance is the result of bacterial plasmid translocation. Bacteria carry their genes on circular rings of bacterial DNA and on small, physically separate molecules known as plasmids. Plasmids are unique because they are replicons that are capable of replication autonomously within a suitable host. Researchers radioactively marked plasmids in bacterial specimens and noted that they could be easily transmitted from one bacterium to another via horizontal gene transfer. They then observed that the genes transferred from the plasmid could be incorporated into the bacteria’s genetic makeup. These genetic alterations enhanced survivorship within the environment and promoted resistance to antibiotics. They concluded that plasmids carry genes important for survival and facilitate bacterial resistance to antibiotics.

Study 2

Researchers in this study state that resistance is the result of the misuse of antibiotics. Researchers administered various antibiotics to a culture of E. coli and studied their effects over time (Figure 1). They concluded that bacterial resistance is the result of natural selection. In other words, the strongest bacteria survive antibiotics and reproduce, which produces anitbiotic-resistant offspring bacteria. 

Figure 1

How were plasmids marked and traced in Study 1?

Bacterial resistance is a common issue encountered in various infections. Scientists have attributed this phenomenon to the overuse of anti-bacterial sanitizers and prescription antibiotics. Two groups of researchers performed studies to test bacterial resistance.

Study 1

Researchers in this study state that bacterial resistance is the result of bacterial plasmid translocation. Bacteria carry their genes on circular rings of bacterial DNA and on small, physically separate molecules known as plasmids. Plasmids are unique because they are replicons that are capable of replication autonomously within a suitable host. Researchers radioactively marked plasmids in bacterial specimens and noted that they could be easily transmitted from one bacterium to another via horizontal gene transfer. They then observed that the genes transferred from the plasmid could be incorporated into the bacteria’s genetic makeup. These genetic alterations enhanced survivorship within the environment and promoted resistance to antibiotics. They concluded that plasmids carry genes important for survival and facilitate bacterial resistance to antibiotics.

Study 2

Researchers in this study state that resistance is the result of the misuse of antibiotics. Researchers administered various antibiotics to a culture of E. coli and studied their effects over time (Figure 1). They concluded that bacterial resistance is the result of natural selection. In other words, the strongest bacteria survive antibiotics and reproduce, which produces anitbiotic-resistant offspring bacteria. 

Figure 1

E. coli is commonly found in the digestive tract of mammals and helps facilitate digestion. It is beneficial under normal conditions but can cause illness if populations grow out of control. Given the information present in Study 2, would it be wise to administer a patient penicillin for more than 15 days?

Bacterial resistance is a common issue encountered in various infections. Scientists have attributed this phenomenon to the overuse of anti-bacterial sanitizers and prescription antibiotics. Two groups of researchers performed studies to test bacterial resistance.

Study 1

Researchers in this study state that bacterial resistance is the result of bacterial plasmid translocation. Bacteria carry their genes on circular rings of bacterial DNA and on small, physically separate molecules known as plasmids. Plasmids are unique because they are replicons that are capable of replication autonomously within a suitable host. Researchers radioactively marked plasmids in bacterial specimens and noted that they could be easily transmitted from one bacterium to another via horizontal gene transfer. They then observed that the genes transferred from the plasmid could be incorporated into the bacteria’s genetic makeup. These genetic alterations enhanced survivorship within the environment and promoted resistance to antibiotics. They concluded that plasmids carry genes important for survival and facilitate bacterial resistance to antibiotics.

Study 2

Researchers in this study state that resistance is the result of the misuse of antibiotics. Researchers administered various antibiotics to a culture of E. coli and studied their effects over time (Figure 1). They concluded that bacterial resistance is the result of natural selection. In other words, the strongest bacteria survive antibiotics and reproduce, which produces anitbiotic-resistant offspring bacteria. 

Figure 1

How are plasmids transmitted from one bacterium to another?

Hormones are biochemical messengers utilized by multicellular organisms to coordinate development and behaviors. Hormones are secreted by the endocrine system and are key components in signal cascades that result in various essential activities. Plants, like animals, depend on hormonal signals for physiological adaptation and development.

There are several hormones that are primarily involved with seed germination and sprout formation. Abscisic acid, in high concentrations, prevents seed germination. Auxins are compounds that positively influence cell enlargement, the formation of buds, and the development of roots. Cytokinins influence cell division and shoot formation. Gibberellins promote seed germination as well as flowering and growth post-germination.

Study 1

Several scientists soaked Zea mays (corn) seeds in solutions rich in certain plant hormones. They observed and recorded seed germination and development over a three week period. At the end of the three week period, they measured coleoptile (the protective extension of sprout) and radicle (the primary root) growth of the seeds and plotted them in a graph (Figure 1).

Figure 1

Study 2

Scientists exposed Zea mays (corn) seeds to several hormonal treatments and measured coleoptile growth over a 14-day period and recorded their observations in a line graph (Figure 2). The groups consisted of a control exposed to saline solution, a treatment group exposed to a 0.15 millimolar solution of abscisic acid, and a treatment group exposed to a solution that included 0.15 millimoles of abscisic acid and 0.20 millimoles of gibberellins.

Figure 2

A fire devastates an area. Seeds begin to germinate several months later. Scientists study the hormonal composition on the germinating seeds. Which hormone would the scientists of Study 2 expect to find in the greatest level?

Hormones are biochemical messengers utilized by multicellular organisms to coordinate development and behaviors. Hormones are secreted by the endocrine system and are key components in signal cascades that result in various essential activities. Plants, like animals, depend on hormonal signals for physiological adaptation and development.

There are several hormones that are primarily involved with seed germination and sprout formation. Abscisic acid, in high concentrations, prevents seed germination. Auxins are compounds that positively influence cell enlargement, the formation of buds, and the development of roots. Cytokinins influence cell division and shoot formation. Gibberellins promote seed germination as well as flowering and growth post-germination.

Study 1

Several scientists soaked Zea mays (corn) seeds in solutions rich in certain plant hormones. They observed and recorded seed germination and development over a three week period. At the end of the three week period, they measured coleoptile (the protective extension of sprout) and radicle (the primary root) growth of the seeds and plotted them in a graph (Figure 1).

Figure 1

Study 2

Scientists exposed Zea mays (corn) seeds to several hormonal treatments and measured coleoptile growth over a 14-day period and recorded their observations in a line graph (Figure 2). The groups consisted of a control exposed to saline solution, a treatment group exposed to a 0.15 millimolar solution of abscisic acid, and a treatment group exposed to a solution that included 0.15 millimoles of abscisic acid and 0.20 millimoles of gibberellins.

Figure 2

What biological system secretes hormones in multicellular organisms?

Hormones are biochemical messengers utilized by multicellular organisms to coordinate development and behaviors. Hormones are secreted by the endocrine system and are key components in signal cascades that result in various essential activities. Plants, like animals, depend on hormonal signals for physiological adaptation and development.

There are several hormones that are primarily involved with seed germination and sprout formation. Abscisic acid, in high concentrations, prevents seed germination. Auxins are compounds that positively influence cell enlargement, the formation of buds, and the development of roots. Cytokinins influence cell division and shoot formation. Gibberellins promote seed germination as well as flowering and growth post-germination.

Study 1

Several scientists soaked Zea mays (corn) seeds in solutions rich in certain plant hormones. They observed and recorded seed germination and development over a three week period. At the end of the three week period, they measured coleoptile (the protective extension of sprout) and radicle (the primary root) growth of the seeds and plotted them in a graph (Figure 1).

Figure 1

Study 2

Scientists exposed Zea mays (corn) seeds to several hormonal treatments and measured coleoptile growth over a 14-day period and recorded their observations in a line graph (Figure 2). The groups consisted of a control exposed to saline solution, a treatment group exposed to a 0.15 millimolar solution of abscisic acid, and a treatment group exposed to a solution that included 0.15 millimoles of abscisic acid and 0.20 millimoles of gibberellins.

Figure 2

The proper term for the shoot or sprout section of the germinating seed is which of the following?

Hormones are biochemical messengers utilized by multicellular organisms to coordinate development and behaviors. Hormones are secreted by the endocrine system and are key components in signal cascades that result in various essential activities. Plants, like animals, depend on hormonal signals for physiological adaptation and development.

There are several hormones that are primarily involved with seed germination and sprout formation. Abscisic acid, in high concentrations, prevents seed germination. Auxins are compounds that positively influence cell enlargement, the formation of buds, and the development of roots. Cytokinins influence cell division and shoot formation. Gibberellins promote seed germination as well as flowering and growth post-germination.

Study 1

Several scientists soaked Zea mays (corn) seeds in solutions rich in certain plant hormones. They observed and recorded seed germination and development over a three week period. At the end of the three week period, they measured coleoptile (the protective extension of sprout) and radicle (the primary root) growth of the seeds and plotted them in a graph (Figure 1).

Figure 1

Study 2

Scientists exposed Zea mays (corn) seeds to several hormonal treatments and measured coleoptile growth over a 14-day period and recorded their observations in a line graph (Figure 2). The groups consisted of a control exposed to saline solution, a treatment group exposed to a 0.15 millimolar solution of abscisic acid, and a treatment group exposed to a solution that included 0.15 millimoles of abscisic acid and 0.20 millimoles of gibberellins.

Figure 2

The proper term for the root section of the germinating seed is which of the following?

Drosophila melanogaster, the common fruit fly, is frequently utilized for genetic studies due to its simple food requirements, hardy nature, and because it completes its life cycle within 12 days at room temperature. This particular fly species has four pairs of chromosomes with traits that have been studied and observed to be inherited in a Mendelian fashion.

The predictive capacity of Mendelian genetics depends on traits whose physiological characteristics, know as phenotypes, are determined by genetic combinations of alleles, known as genotypes. The exhibition of observable traits is determined by the combination of two alleles for a specific characteristic. For example, the dominant allele for the wild type red eye color is E and the recessive sepia-brown color is e. Likewise, the dominant allele for long wings is W and the recessive allele for short wings is w. When a dominant allele is present with a recessive one, the organism physically exhibits the trait of the dominant allele and the organism is known as heterozygous for that trait. If an organism has two dominant or two recessive alleles for a particular trait, it is known as homozygous for that trait. Only when two recessive alleles are present does the organism physically exhibit the trait of the recessive allele. Heterozygous individuals are often known as carriers because the dominant allele phenotype masks the recessive allele phenotype and the organism can carry the recessive allele without exhibiting any of its physical traits.

Study 1

A researcher wants to study the inheritance of eye color in fruit flies. The scientist mates a homozygous recessive (ee) group with a homozygous dominant (EE) group in order to obtain the F1 Generation. Two members of the F1 Generation were then mated in order to obtain the F2 Generation (Table 1).

Table 1

Study 2

A researcher decided to perform a dihybrid cross of fruit flies possessing red eyes and long wings with fruit flies possessing sepia-brown eyes and short wings. The scientist bred homozygous dominant flies with homozygous recessive flies in the F1 Generation. The members of the F1 Generation were then mated in order to obtain the F2 Generation (Table 2).

Table 2

At what temperature do fruit flies complete their lifespan in 12 days?

Drosophila melanogaster, the common fruit fly, is frequently utilized for genetic studies due to its simple food requirements, hardy nature, and because it completes its life cycle within 12 days at room temperature. This particular fly species has four pairs of chromosomes with traits that have been studied and observed to be inherited in a Mendelian fashion.

The predictive capacity of Mendelian genetics depends on traits whose physiological characteristics, know as phenotypes, are determined by genetic combinations of alleles, known as genotypes. The exhibition of observable traits is determined by the combination of two alleles for a specific characteristic. For example, the dominant allele for the wild type red eye color is E and the recessive sepia-brown color is e. Likewise, the dominant allele for long wings is W and the recessive allele for short wings is w. When a dominant allele is present with a recessive one, the organism physically exhibits the trait of the dominant allele and the organism is known as heterozygous for that trait. If an organism has two dominant or two recessive alleles for a particular trait, it is known as homozygous for that trait. Only when two recessive alleles are present does the organism physically exhibit the trait of the recessive allele. Heterozygous individuals are often known as carriers because the dominant allele phenotype masks the recessive allele phenotype and the organism can carry the recessive allele without exhibiting any of its physical traits.

Study 1

A researcher wants to study the inheritance of eye color in fruit flies. The scientist mates a homozygous recessive (ee) group with a homozygous dominant (EE) group in order to obtain the F1 Generation. Two members of the F1 Generation were then mated in order to obtain the F2 Generation (Table 1).

Table 1

Study 2

A researcher decided to perform a dihybrid cross of fruit flies possessing red eyes and long wings with fruit flies possessing sepia-brown eyes and short wings. The scientist bred homozygous dominant flies with homozygous recessive flies in the F1 Generation. The members of the F1 Generation were then mated in order to obtain the F2 Generation (Table 2).

Table 2

How many pairs of chromosomes does the typical Drosophila melanogaster possess?

Drosophila melanogaster, the common fruit fly, is frequently utilized for genetic studies due to its simple food requirements, hardy nature, and because it completes its life cycle within 12 days at room temperature. This particular fly species has four pairs of chromosomes with traits that have been studied and observed to be inherited in a Mendelian fashion.

The predictive capacity of Mendelian genetics depends on traits whose physiological characteristics, know as phenotypes, are determined by genetic combinations of alleles, known as genotypes. The exhibition of observable traits is determined by the combination of two alleles for a specific characteristic. For example, the dominant allele for the wild type red eye color is E and the recessive sepia-brown color is e. Likewise, the dominant allele for long wings is W and the recessive allele for short wings is w. When a dominant allele is present with a recessive one, the organism physically exhibits the trait of the dominant allele and the organism is known as heterozygous for that trait. If an organism has two dominant or two recessive alleles for a particular trait, it is known as homozygous for that trait. Only when two recessive alleles are present does the organism physically exhibit the trait of the recessive allele. Heterozygous individuals are often known as carriers because the dominant allele phenotype masks the recessive allele phenotype and the organism can carry the recessive allele without exhibiting any of its physical traits.

Study 1

A researcher wants to study the inheritance of eye color in fruit flies. The scientist mates a homozygous recessive (ee) group with a homozygous dominant (EE) group in order to obtain the F1 Generation. Two members of the F1 Generation were then mated in order to obtain the F2 Generation (Table 1).

Table 1

Study 2

A researcher decided to perform a dihybrid cross of fruit flies possessing red eyes and long wings with fruit flies possessing sepia-brown eyes and short wings. The scientist bred homozygous dominant flies with homozygous recessive flies in the F1 Generation. The members of the F1 Generation were then mated in order to obtain the F2 Generation (Table 2).

Table 2

Drosophila melanogaster is commonly known as which of the following?