CBSE 12TH BIOLOGY - Online Test
Q1.
Which organism is shown in figure below
Answer : Option B
Explaination / Solution:
The plants parts shown below is the leaf of Bryophyllum having small plantlets on its margin. The vegetative reproduction by leaves occurs in this species.
Q2. Xerosere that begins on sand is called:
Answer : Option C
Explaination / Solution:
A psammosere is a seral community, an ecological succession that began life on newly exposed coastal sand. Most common psammoseres are sand dune systems.
Q3. In 1997, an American company got patent rights on
Answer : Option B
Explaination / Solution:
In September 1997 Texas, USA company RiceTec was granted U.S. Patent No. 5,663,484 on "basmati rice lines and grains." The patent secures lines of basmati and basmati-like rice and ways of analyzing that rice. RiceTec, owned by Prince Hans-Adam of Liechtenstein, faced international outrage over allegations of biopiracy.
Q4. Contraceptive oral pills help in birth control by
Answer : Option C
Explaination / Solution:
Contraceptive pills contain hormone progestogens or estrogen or combination of both. These hormones prevent the ovulation and prevent the pregnancy.
Q5. The fusion of two polar nuclei with one male gamete is called
Answer : Option D
Explaination / Solution:
The process of fusion of two polar nuclei with one male gamete is called as triple fusion. The resulting cell becomes primary endosperm cells that forms endosperm.
Q6. Population ecology makes link with
Answer : Option D
Explaination / Solution:
Population ecology is an important area of ecology because it links ecology to population genetics and evolution. At population level natural selection operates to evolve desired traits.
Q7. The drug which binds to specific opioid receptors present in our central nervous system and gastrointestinal tract is
Answer : Option D
Explaination / Solution:
Opioids are substances that act on opioid receptors to produce morphine-like effects.
The endogenous opioids are dynorphins, enkephalins, endorphins, endomorphins and nociceptin. The opioid receptors are ~40% identical to somatostatin receptors (SSTRs). Opioid receptors are distributed widely in the brain, and are also found in the spinal cord and digestive tract.
Opioids are most often used medically to relieve pain, and by people addicted to opioids.
Q8. In the synthesis of which of the following, the DNA molecule is not directly involved?
Answer : Option A
Explaination / Solution:
DNA molecules are not directly involved in synthesis of protein. In protein synthesis, DNA, first undergoes transcription process and produce m-RNA. Translation process takes place and produce protein.
Q9. The class of domesticated fowl or bird used for food or their egg is called
Answer : Option C
Explaination / Solution:
Poultry is the class of domesticated fowl or bird used for their meat or their egg. They include chicken, duck and sometimes turkey and geese.
Q10. Match the following:
state
a) Andhra Pradesh
b) Gujarat
c) Sikkim
d) Karnataka
sanctuary
i) Barsey rhododendron sanctuary
ii) Dandeli wildlife sanctuary
iii) Manjira wildlife sanctuary
iv) Sansagir wildlife sanctuary
state
a) Andhra Pradesh
b) Gujarat
c) Sikkim
d) Karnataka
sanctuary
i) Barsey rhododendron sanctuary
ii) Dandeli wildlife sanctuary
iii) Manjira wildlife sanctuary
iv) Sansagir wildlife sanctuary
Answer : Option D
Explaination / Solution:
- Manjira wildlife sanctuary Located across the Manjira River, this wildlife sanctuary is situated in the Medak district in Andhra Pradesh (Now in Telangana).
- Also known as Sasan-Gir, or Gir forest, this is a forest and wildlife sanctuary in Gujarat, established in 1965.
- The Varsey Rhododendron Sanctuary or Barsey Rhododendron Sanctuary occupies 104 km² in the Singalila Range in western Sikkim. It borders on Nepal to the west, and on the state of West Bengal to the south across the Rambong Khola stream.
- Dandeli Wildlife Sanctuary is the second largest sanctuary in Karnataka.
