Question 1

Which of the following statements about adaptive radiation is false?

Accepted Answer

The statement about adaptive radiation that is false is that adaptive radiation is not driven by natural selection. The process occurs as the result of natural selection.
Key Takeaway: Adaptive radiation is a rapid evolutionary process characterized by an increase in the morphological and ecological diversity of a single, rapidly dividing lineage. It often occurs in organisms without a defined niche, as the species may radiate rapidly to take advantage of all of the unoccupied niches. In Lake Victoria, a lake in the African rift valley, over 300 new species radiated from a single lineage over the course of 15,000 years.

Question 2

Which of the following is not a biotic factor?

Accepted Answer

The component that is not a biotic factor is water. While essential to life, water is a biotic factor.
Key Takeaway: Biotic factors are any component of an ecosystem that is a part of or was derived from a living organism. Most contain carbon and are thus capable of decay. Examples other than those above include cotton, wood, bark, and linoleum. Biotic factors have many uses and purposes within the biome, ranging from fossil fuels powering locomotion to straw being used as food for animals.

Question 3

During what stage of embryonic development does organ differentiation occur?

Accepted Answer

Organ differentiation in an embryo occurs during the gastrula stage. It is during gastrulation that the three germ layers arise.
Key Takeaway: The process of gastrulation results in the formation of the three germ layers, ectoderm endoderm, and mesoderm. It is these three layers that give rise to all the tissues and organs of the body. The endoderm forms the tissues of the digestive system as well as the lungs and thyroid. The ectoderm forms the central nervous system, epidermis, hair, and mammary glands. The mesoderm forms the skeleton, skeletal muscle, heart, blood, and spleen.

Question 4

Which of the following are transport tissues in vascular plants? I. Root
II) Xylem
III) Phloem

Accepted Answer

The transport tissues in vascular plants are the xylem and the phloem. The roots serve to absorb and store nutrients.
Key Takeaway: The xylem's main function is to transport water and nutrients absorbed by the roots to the stem and leaves. The phloem serves to transport organic materials from the leaves to the roots for storage. The xylem is composed mostly of dead cells and transports water and nutrients via processes that do not require energy. The phloem is composed of living cells that transport sap, which is a water-based substance that is rich in photosynthetic sugars.

Question 5

In translation, the first codon always codes for what amino acid?

Accepted Answer

In translation, the first codon always codes for methionine. Methionine serves as a signal for translation to commence.
Key Takeaway: Translation is the process that creates protein by using mRNA as a template. Translation is always initiated by the start codon, which codes for methionine. Each codon is a three nucleotide sequence that codes for a specific amino acid. Each new amino acid is bound to the previous amino acid by a peptide bond. This process continues until one of three stop codons is encountered, and this ends the process and a new protein has been synthesized.

Question 6

Which of the following is the complementary base strand to the sequence AGCGTATTGCG?

Accepted Answer

The complementary base strand to the sequence AGCGTATTGCG is TCGCATAACGC. In DNA, adenine pairs with thymine and guanine pairs with cytosine.
Key Takeaway: The pairing of nitrogenous bases in DNA was first described in the Watson-Crick base pairing model, which also described the double-helix structure of DNA. This model accounts for the fact that in numerous organisms, adenine and thymine are always present in DNA at the same amounts, as are guanine and cytosine. In DNA, the paired bases are bound together by hydrogen bonds.

Question 7

"The California Right to Know Genetically Modified Food Act" known as Proposition 37 will require food manufacturers to label food with genetically modified ingredients (GMOs). If the bill passes, it will be the first law in the United States that required GMO labeling. Some European countries already mandate GMO labeling, but efforts to pass legislation in the United States have met resistance. Over a dozen other states have failed to pass proposed labeling laws. Food manufacturer argue that the bill is unnecessary because GMO are safe. They believe labeling will drive up food costs and will confuse consumers. Proponents of the legislation assert that consumers have a right to know what is in their food.
Genetic modification, also called genetic engineering, the alteration of genetic material through processes not found in nature. Scientists use genetically modified organisms to protect crops. add variety to certain foods. Some people believe that the genetic modification of foods effects safety. Corporations that produce genetically modified foods point to hundreds of studies that show that they are safe. California voters will soon make a choice about GMO foods labels, and both sides are spending millions of dollars to influence their decisions. The result of the ballot initiative will reverberate throughout the nation.
How do proponents of Proposition 37 in California hope their efforts will compare to those of advocates of GMO labeling in other states?

Accepted Answer

California advocates for GMO labeling hope they will be more successful in their efforts than advocates in other states have been. Since legislation to require GMO labeling has failed in over a dozen states, those who support labeling in CA would hope to be more successful. Success in CA would likely lead to new legislation around the country.

Quiz 1: Health Occupations Basic Entrance (HOBE)

Which of the following statements about adaptive radiation is false?

Which of the following is not a biotic factor?

During what stage of embryonic development does organ differentiation occur?

Which of the following are transport tissues in vascular plants? I. Root II) Xylem III) Phloem

In translation, the first codon always codes for what amino acid?

Which of the following is the complementary base strand to the sequence AGCGTATTGCG?