31. A layer of cells immediately surrounding the ovum but outside the zona pellucida is called__.
[A] germinal epithelium
[B] corona radiata
[C] theca interna
[D] membrane granulosa
Show Answer
Correct Answer: B [corona radiata]
Notes:
A layer of cells immediately surrounding the ovum but outside the zona pellucida is called corona radiata.
32. The outermost layer of the ovary is made up of ___.
[A] simple cuboidal cells
[B] stereocilia
[C] stroma
[D] cilia
Show Answer
Correct Answer: A [simple cuboidal cells]
Notes:
Ovarian or germinal epithelium is the outermost layer of the ovary composed of simple cuboidal cells. It is actually a modified visceral peritoneum.
33. Which of the following disease is transmitted by animal bite and saliva?
[A] Rabies
[B] Tuberculosis
[C] Tetanus
[D] AIDS
Show Answer
Correct Answer: A [Rabies]
Notes:
Rabies disease is transmitted by animal bites and saliva.
34. Huntington’s disease and Marfan syndrome are examples of which of the following disorder?
[A] Sex-linked recessive
[B] Sex-linked dominant
[C] Autosomal dominant
[D] None of these
Show Answer
Correct Answer: C [Autosomal dominant]
Notes:
Huntington’s disease and Marfan syndrome are examples of autosomal dominant disorders. One of many ways that a trait or disorder can be passed down through families is called autosomal dominant.
35. Some strains of Bacillus thuringiensis can kill certain insects such as __.
[A] Lepidoptera
[B] scorpion
[C] fruit fly
[D] dragonfly
Show Answer
Correct Answer: A [Lepidoptera]
Notes:
Some strains of Bacillus thuringiensis can kill certain insects such as Lepidoptera. They are an order of insects consisting of moths and butterflies.
36. Which of the following makes the skin layer impervious to water?
[A] Melanin
[B] Collagen
[C] Keratin
[D] Chitin
Show Answer
Correct Answer: C [Keratin]
Notes:
Keratin is a family of fibrous structural proteins involved in making up the outer layer of human skin. It is also the key structural component of hair and nails. Cells in the epidermis contain a structural matrix of keratin, which makes this outermost layer of the skin almost waterproof, and along with collagen and elastin, gives skin its strength. It also makes up fish scales and crustacean shells, bird feathers and beaks, animal horns and hooves.
37. The method not used as a Biological control is ____:
[A] Pheromone traps
[B] Use of pesticides
[C] Use of predators of a pest
[D] Use of Neem extracts
Show Answer
Correct Answer: B [Use of pesticides]
Notes:
Pesticides are substances or mixture of substances intended for preventing, destroying, repelling or mitigating any pest. Pesticides are a special kind of products for crop protection. A pesticide is generally a chemical or biological agent (such as a virus, bacterium, antimicrobial or disinfectant) that through its effect deters, incapacitates, kills or otherwise discourages pests. Target pests can include insects, plant pathogens, weeds, molluscs, birds, mammals, fish, nematodes (roundworms), and microbes that destroy property, cause nuisance, spread disease or are vectors for disease.
38. Which of the digestive organs contains acid?
[A] Stomach
[B] Colon
[C] Small intestine
[D] Appendix
Show Answer
Correct Answer: A [Stomach]
Notes:
Gastric acid, gastric juice or stomach acid, is a digestive fluid, formed in the stomach. It is composed of hydrochloric acid (HCl), potassium chloride (KCl) and sodium chloride (NaCl). Gastric acid plays a key role in digestion of proteins, by activating digestive enzymes.
39. Which of the following is a vestigial organ in human body?
[A] Spleen
[B] Thyroid
[C] Gall bladder
[D] Wisdom teeth
Show Answer
Correct Answer: D [Wisdom teeth]
Notes:
Evolutionary biologists now classify wisdom teeth as vestigial organs, or body parts that have become functionless due to evolution. They believe wisdom teeth, or the third set of molars, were the evolutionary answer to our ancestor’s early diet of rough food – like leaves, roots, nuts and meats – which required more chewing power and resulted in excessive wear of the teeth. The modern diet with its softer foods has made the need for wisdom teeth nonexistent.
40. Which of the following microorganisms is used in milk curdling?
[A] Bacillus
[B] Lactobacillus
[C] Leuconostoc
[D] Acetobacter
Show Answer
Correct Answer: B [Lactobacillus]
Notes:
Lactobacillus acidiphilous is used in milk curdling by producing lactic acid and reducing the pH of the milk. These bacteria convert the lactose into lactic acid, which imparts the sour taste to curd. It is a genus of Gram positive facultative anaerobic or microaerophilic rod-shaped bacteria.