USA test prep : genetics science

DNA, amino acids, and proteins are all molecules that play a vital role in your life, even though you have never seen them. In fact, these three types of molecules are tightly linked. What is the relationship between them?

DNA codes call for specific amino acids, which are assembled into proteins needed by your body.

What are the steps in SCNT? Order these steps so you can complete your own cloning project.

D, C, E, F, A, B

DNA and RNA differ in all BUT one of the following ways.

DNA contains the base uracil, while RNA contains the base thymine instead

The forrested areas of New England today resemble this satellite image of a Connecticut location. Rapid population growth directly impacts biodiversity on Earth by ALL BUT one of these issues. That is

fossil fuel consumption

Changes in a DNA sequence that affect genetic information are known as

Mutations. Mutations are changes in DNA sequences.

In an experiment, Mendel grew 633 green pea plants with either wrinkled seed-coats (dominant) or smooth (recessive). If the ratio of the wrinkled seed-coat plants to the straight seed-coat plants was 3:1, how many straight seed-coat plants did he grow?

158.

Two Rh+ parents have children. What is the probability that any offspring will NOT be able to receive a transfusion from either parent?

25%

Which situation is a good illustration of a biologically resistant species?

A staph bacteria in a hospital that is not killed by penicillin or several other antibiotics

Energy from food must be transformed into the bonds of _________ before it can be used by cells

ATP

In pole beans, green pods (G) are a dominant trait, while yellow pods (g) are a recessive trait. A bean plant with a GG genotype is crossed with a second plant that has the gg genotype. If this cross produces 500 offspring, approximately how many of the offspring will have green pods?

All 500 of the offspring will have the dominant (G) allele, so all 500 will be green.

James was sick, went to the doctor, and was diagnosed with a bacterial throat infection. His infection was treated with antibiotics. In a few days, James felt much better, but some resistant bacteria survived and, overnight, James was sick again. This time, he had to take a much stronger antibiotic. The resistant bacterial cells illustrate what characteristic of life?

All living things adapt to changes in their environment.

Start with the P generation with the following genotypes (AA x aa). Based on classical Mendelian inheritance, how will a cross between two homozygous parents, one dominant and one recessive, influence future generations?

Although the F1 generation will all show the dominant trait, the offspring will all be heterozygous and increase chances of future variation

It has been discovered that this type of cell is found in humans and is more numerous in humans than there are human cells themselves. Most of these are beneficial and aid in processes such as digestion and disease fighting, although some of them can be pathogenic. Which of these types of cells is described here?

Bacterial cells

Mutations can be both harmful and helpful. Indicate which of these can be caused by a genetic mutation.

Cystic fibrosis

In sunflowers, tall stems (T) is a dominant trait while short stems (t) is a recessive trait. In a field of 1000 sunflowers, 820 are tall plants and 180 are short. Which statement BEST describes the genotype of the sunflowers in the field?

about 50% will be heterozygous for tall stems,

Membrane proteins are among the most important proteins biologically because they allow cells to communicate with their environments. In humans, they determine whether the immune system recognizes the cell as foreign or not and they are the targets of most pharmaceuticals. In all organisms, membrane proteins are responsible for other functions as well. One function determines when and if cell division takes place. That is

activation of growth hormones.

Strawberry plants can reproduce several ways. A strawberry plant's main stem is called a crown. This crown produces spirals of leaves, runners, and flowers. The flowers become the strawberries that we love to eat. When days are long and warm, the plant produces runners. Runners are offshoots of the parent plant, sometimes called stolons. These runners are stems growing out from the crown along the ground. The runners grow roots and along the runner, "daughter plants" can develop. Most commercial strawberry growers use runners to produce new plants. Runners are a type of ___________ reproduction in strawberry plants.

asexual reproduction

The total amount of organic matter present in any trophic level is called

biomass.

According to Mendel's _______________, one copy of a gene is passed randomly from each parent to their offspring. This is why gametes have half the usual number of chromosomes. The ______________ states that different genes are not connected. In other words, the gene for eye color is not influenced by, nor does it influence, the gene for hair color. This allows gametes to form with a random mixture of traits. The cell division that creates gametes according to these principles is known as __________.

Law of Segregation; Law of Independent Assortment; meiosis

In nature, most plants reproduce using pollen containing sperm to fertilize eggs. Scientists produce many plants in the lab by cloning; culturing a few plant cells in a test tube of chemical medium. Few cells grow into a new plant. It is easy for scientists to produce many plants from just a few cells. Where would you add "cloning" to the Venn diagram?

Mitosis. Cloning is an asexual method of reproduction. It requires that cells divide over and over, making exact copies of the original cell. That describes mitosis.

All of the statements EXCEPT one are true about mutations. Which statement is false?

Mutations must be present in parents and then passed to offspring. It IS possible for parents to pass on a mutation, if there is an error in meiosis or in the processes that create sperm or eggs. But mutations may arise directly in the offspring's DNA.

As a result of _______________, the incorrect sequence of amino acids will be translated into a protein, resulting in a mutation

deletion,

Gene therapy is an integral part of genome projects. It includes the correction of abnormal genes responsible for diseases. Which of these is an application of gene therapy?

designing drugs to inhibit the function of a protein coded by an abnormal gene.

How could stem cells prove helpful in the treatment of cardiovascular diseases?

differentiated to form heart muscle cells,

Transport of materials into a cell against a concentration gradient, from low to high, requires

energy.

Chromosomes, which contain DNA, have several functions. All BUT ONE of these statements is a function of chromosomes.

help an organism produce usable energy.

Which conclusion might be drawn between the relationship found in the graphs of Global Carbon Emissions and Global Temperatures over the past 150 years.

increased Carbon emission from human activities are directly correlated to increased global temperatures

After growing all the plants, students found that all of them were identical to their parent plants. All BUT WHICH statement explains this?

offspring may look much like the parent plant, although genetically different.

Your gender, whether you are male or female, is determined by the

or Y chromosomes, inherited from father.

Following the nuclear reactor accidents in Japan in April, 2011, some people were exposed to high levels of radiation. Children born to these people in the future could have mutations if these mutations occurred in the parents'

parents' sex cells

YOUR GOAL: You are studying how a particular gene, named Insom, might play a role in insomnia. You want to study mice with this gene turned off. To knockout the Insom gene you will

replace it with a mutated, inactive copy of Insom.

The debate regarding viruses continue. According to this passage, some consider viruses to be alive because they

respond to stimuli.

Which of these is the BEST source of stem cells and minimizes the risk associated with stem cell transplantation?

stem cells selected from the umbilical cord and preserved for use

Structurally, DNA and RNA nucleotides are similar, although their three basic components differ slightly. One way DNA and RNA differ is in their

type of 5-carbon sugars.

If a man is heterozygous (Aa) for a trait, predict his possible sperm.

50% would carry a dominant (A) and 50% would carry a recessive (a)

The by-products of cellular respiration include

Carbon dioxide and water

food pyramid is sometimes used to show both the flow of matter and energy in an ecosystem. The pyramid narrows as matter and energy flow from the bottom to the top. What does this pyramid tell you about the energy in this ecosystem

Energy decreases from bottom to top because some is used at each level for life processes

The trait of "freckles" is recessive and represented by a. No freckles is dominant and represented by A. A researcher crossed two individuals, one homozygous dominant and the other heterozygous for freckles. Based on the data in the Punnett square, the researcher concluded that all offspring would have dominant as well as the recessive alleles. What comment would you make about his conclusion?

He is incorrect. The homozygous dominant individual cannot provide a recessive allele.

Which organism is responsible for the production of fermented dairy products, such as yogurt and cheese?

Lactobacillus bacteria.

How can a genetic disorder, such as Turner's syndrome, occur?

Nondisjunction during meiosis. When homologous chromosomes line up during prophase I, if they remain stuck together, one side of the cell in the egg or sperm, will lack an X chromosome.

What is the correct description of the relationship between osmosis and diffusion?

Osmosis is a type of diffusion that occurs across a cell membrane

You have been instructed to develop a classification system for several plants on campus. All four are in the same kingdom, Plantae. Based on the plant traits listed in the table, which set of divisions should you make?

Division 1 - vascular or nonvascular Division 2 - seeds or no seeds Division 3 - flowering or nonflowering

Organisms that reproduce sexually produce sex cells or gametes via meiosis, while body or somatic cells are produced via mitosis. As noted in the Venn diagram, somatic cells are 2N while gametes are N. What process restores the 2N chromosome number in a zygote's somatic cells for growth and development to continue?

The process that restores the 2N or diploid chromosomes number in ANY organism that reproduces sexually is fertilization.

The incidence of Edward's Syndrome is estimated to one in 3,000 live births and this increases as the mother's age increases. The syndrome has a very low rate of survival, resulting from heart abnormalities, kidney malformations, and other internal organ disorders. Based on the karyotype, what would be another name for Edward's Syndrome?

Edward's Syndrome is also known as Trisomy 18. Looking at the karyotype, there are three copies of the number 18 chromosome. Trisomy is the term used to describe the presence of an extra chromosome due to nondisjunction.

All of the following circumstances, EXCEPT ___________ can produce new combinations of genetic traits in sperm and eggs that are different from the parents.

Errors during mitosis. Mitosis is strictly used for growth and replacement of cells within the organism itself in animals, as traits are passed on via cell division by meiosis.

Changes in the DNA sequence, or mutations, help drive

Evolutionary change in species is driven by changes in DNA

Which process describes the ATP-requiring movement of extremely large substances out of a cell in pockets called vesicles?

Exocytosis.

Farmer Jones has a herd of cows. Brown coat is dominant over white coat in cows and his cows are all brown. Farmer Jones likes brown cows and wants to keep his herd brown by selling off any heterozygous cows. Heterozygous cows are brown but have the recessive gene for white coat.Suppose Farmer Jones wants to do a test cross of his cows to see what type of genotypes are carried for coat color throughout his herd. What is the genotype of the control bulls he should use to test for the heterozygous genotype?

Homozygous recessive,This allows all genes to show up in the offspring. A heterozygous brown cow crossed with a homozygous white bull will produce offspring of both colors, white and brown, in a 1:4 ratio. Crossing with a dominant animal can mask recessive genes.

Transcription translation errors often result in physical, or ___________, changes in an organism.

Phenotypic

In pigs, the allele for a wavy, rough coat (R) is dominant to the allele for a soft, fine coat (r). A rough coat boar and a soft coat sow mate. They produce several litters, 50% are rough coat and 50% are smooth coat. What were the genotypes of the parents?

Rr × rrThis would give the expected ratio.

Why would too much salt intake cause someone to develop high blood pressure?

Salt in the bloodstream causes fluids to enter the blood from surrounding cells, due to osmosis.

Water harvesting worldwide would impact conservation efforts positively for several reasons. Which harvesting result would NOT be an ecological advantage?

Since this method is so expensive it does not benefit the poorer countries.

Natural selection can lead to the formation of a new species which is called

Speciation

A karyotype of a person with Down syndrome is shown here. Which term is used to describe this type of genetic disorder?

TRISOMY.

DNA, RNA, and starch: What do these three important biomolecules have in common?

The presence of at least one carbon-based sugar

Imagine the pH of the environment in which the hydrolysis of sucrose is to occur has dropped to 2. How will this drop in pH influence point D in the model?

The substrate (A) will no longer fit into the active site (C) because the enzyme has changed shape.

When viewing a human karyotype to detect genetic disorders, which situation would indicate a genetic problem?

Three chromosomes in any one set. All chromosomes occur as homologous pairs from mom and from dad.

If bed bugs had never been exposed to DDT in the 1950's and 1960's, how would you expect that to affect bed bugs' resistance to pyrethroids during the last decade?

Without the use of DDT, natural selection would not have favored any mutations that provided protection from pesticides; bed bugs would be more susceptible to today's chemicals.