Rod-shaped bacteria are called
Answer: A
Correct answer: Bacillus
Rod-shaped bacteria are bacilli. Spherical ones are cocci, comma-shaped ones vibrios, and rigid helical ones spirilla. Note that bacillus describes the shape, while Bacillus with a capital is a particular genus.
Please log in or register to report this question.
_______ are the agents that act as carriers of a pathogen and spread diseases.
Answer: A
Correct answer: Vectors
A vector is an organism - usually an insect - that carries a pathogen from one host to another: the Anopheles mosquito for malaria, Aedes for dengue, the housefly for typhoid. Controlling the vector is often easier than treating the disease.
Please log in or register to report this question.
Milk, if left out of the refrigerator will quickly go sour.
Which one of the following statements is incorrect?
Answer: C
Correct answer: Viruses cause milk to go sour faster.
Milk sours because bacteria ferment its lactose to lactic acid - viruses have nothing to do with it. The other three statements are true: warmth speeds bacterial growth, bacteria are the cause, and the souring is the acid produced.
Please log in or register to report this question.
The shape of a bacillus is generally
Answer: C
Correct answer: Rod like
A bacillus is rod-shaped. Cocci are spherical, vibrios comma-shaped and spirilla helical.
Please log in or register to report this question.
The process by which the amount of nitrogen in the atmosphere stays constant is known as the
Answer: C
Correct answer: nitrogen cycle
The nitrogen cycle keeps atmospheric nitrogen roughly constant: fixation by bacteria and lightning removes N2 from the air, and denitrification returns it. The two processes balance, so the atmosphere stays at about 78% nitrogen.
Please log in or register to report this question.
The status of algae in the aquatic food chain is
Answer: B
Correct answer: producers
Algae photosynthesise, so they make their own food from CO2 and sunlight and stand at the base of the aquatic food chain as producers. Everything else in the water ultimately depends on them - and on the oxygen they release, which is a large share of the world’s supply.
Please log in or register to report this question.
Prokaryotes do not have a
Answer: C
Correct answer: Nuclear membrane
A prokaryote has no nuclear membrane - its chromosome lies free in the cytoplasm as a nucleoid. It does have cytoplasm, ribosomes (of the 70S kind) and a chromosome; what it lacks is that membrane and the other membrane-bound organelles.
Please log in or register to report this question.
To which one of the following types of organism do mushrooms belong?
Answer: C
Correct answer: Fungi
A mushroom is the fruiting body of a fungus. The organism itself is the mycelium spreading through soil or wood; the mushroom appears only to release spores.
Please log in or register to report this question.
Watering crops is called
Answer: B
Correct answer: irrigation
Supplying water to crops is irrigation. Sowing is putting the seed in the ground, tilling is loosening the soil beforehand, and manuring is adding nutrients.
Please log in or register to report this question.
Which one of the following is not produced by the process of fermentation?
Answer: B
Correct answer: Milk
Milk is the raw material, not a product of fermentation - it comes from the animal. Cheese and yoghurt are made by fermenting it, and wine by fermenting grape juice.
Please log in or register to report this question.
