Nokea
Do all bacteria have negative effects and cause infections?
- A. TRUE
- B. FALSE
- C. Sometimes
- D. Not sure
Correct Answer: B
Rationale: Not all bacteria have negative effects and cause infections. While some bacteria can lead to infections, many bacteria are beneficial and essential for various processes in nature and our bodies. Bacteria have diverse roles in ecosystems, including positive impacts like aiding digestion and nutrient recycling. Understanding the balance of beneficial and harmful bacteria is crucial for appreciating their significance in our lives.
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Which hormone is produced by the pineal gland?
- A. insulin
- B. testosterone
- C. melatonin
- D. epinephrine
Correct Answer: C
Rationale: The correct answer is melatonin (Choice C). The pineal gland is responsible for producing melatonin, a hormone that regulates sleep-wake cycles. Insulin (Choice A) is produced by the pancreas and regulates blood sugar levels. Testosterone (Choice B) is primarily produced by the testes in males and in smaller amounts by the ovaries in females. Epinephrine (Choice D) is produced by the adrenal glands and is involved in the body's fight-or-flight response.
In binomial nomenclature, what is the second part of an organismÄ€™s scientific name?
- A. species
- B. phylum
- C. population
- D. kingdom
Correct Answer: A
Rationale: In binomial nomenclature, the scientific name of an organism consists of two parts: the genus name (first part) and the species name (second part). The second part, 'species,' helps differentiate between different organisms within the same genus. This specific naming system is critical for accurate identification and classification of organisms. Hence, the correct answer is 'species.'
Why is DNA crucial for the metabolic activities of the cell?
- A. It initiates cellular mitosis.
- B. It provides cell wall stability.
- C. It increases glucose absorption.
- D. It controls the synthesis of enzymes.
Correct Answer: D
Rationale: DNA is crucial for the metabolic activities of the cell because it contains the genetic information necessary to regulate the synthesis of enzymes. Enzymes are essential for catalyzing biochemical reactions involved in metabolic processes within the cell. DNA controls the production of enzymes, which are vital for driving various metabolic pathways. Therefore, the correct answer is D, as DNA's role in controlling enzyme synthesis is fundamental for the cell's metabolic activities.
How do animal cells divide during cytokinesis?
- A. Contractile ring
- B. Cell plate
- C. Both
- D. None of the above
Correct Answer: A
Rationale: Animal cells divide using a contractile ring during cytokinesis. The contractile ring is composed of actin and myosin filaments and contracts to pinch the cell into two daughter cells. In contrast, cell plate formation is a mechanism observed in plant cells, not animal cells. Therefore, the correct answer is the contractile ring.
The aerodynamic nature of a bird's wing is an example of what central theme in biology?
- A. Heredity.
- B. Ontogeny.
- C. Organisms and their environment.
- D. Structure and function.
Correct Answer: D
Rationale: