General Science Biology Questions (MCQs) for Competitive Exams
1. Which among the following does not have a cell wall?
[A] Euglena
[B] Mycoplasma
[C] Paramecium
[D] Gonyaulax
B [Mycoplasma]
Notes:
Mycoplasma is a genus of bacteria that lacks a cell wall around their cell membrane. Without a cell wall, they are unaffected by many common antibiotics such as penicillin or other beta-lactam antibiotics that target cell wall synthesis. In comparison to other prokaryotes, they are consequently placed in a separate class Mollicutes(mollis, soft; cutis, skin).
2. Which of the following plants is carnivorous?
[A] Cypress Vine
[B] Venus Flytrap
[C] Amaryllis
[D] Hyacinth
B [Venus Flytrap]
Notes:
The Venus flytrap (Dionaea muscipula) is a carnivorous plant native to subtropical wetlands on the East Coast of the United States in North Carolina and South Carolina. It catches its prey chiefly insects and arachnids with a trapping structure formed by the terminal portion of each of the plant’s leaves, which is triggered by tiny hairs on their inner surfaces.
3. Which one of the following statements about Pyrolysis, which is a process for solid waste treatment is incorrect?
- [A] It converts the waste into solid, liquid and gas of which the resultant liquid and gas can be used to produce energy
- [B] The process occurs at a temperature above 430°C at atmospheric pressure
- [C] The process occurs under high pressure at temperature above 430° C
- [D] It is a thermochemical decomposition of organic waste
B [The process occurs at a temperature above 430°C at atmospheric pressure]
Notes:
Pyrolysis is a thermo-chemical decomposition of organic material at elevated temperatures in the absence of oxygen (or any halogen). Pyrolysis generally takes place well above atmospheric pressure at temperatures exceeding above 430 °C.
4. Which of the following is an endemic species?
[A] Horn bill
[B] Nicobar pigeon
[C] Indian Rhino
[D] Pink head duck
A [Horn bill]
Notes:
The Malabar Grey Hornbill is a hornbill that is endemic to the Western Ghats and associated hills of southern India. They are found mainly in dense forest and around rubber or coffee plantations.
5. Which of the following statements about phloem transport is correct?
[A] Phloem transport occurs unidirectionally
[B] Gravity influences phloem transport
[C] Ca+ is the most abundantcation in phloem sap
[D] Sugar is transported in phloem as non-reducing sugar
D [Sugar is transported in phloem as non-reducing sugar]
Notes:
According to mass flow of hypothesis describing the translocation of solute, the food is synthesised in form of glucose, transported in form of non-reducing sugar through sieve cells and stored in form of starch. Therefore, translocation of solutes is active process that requires expenditure of energy.
6. Which one of the following is the respiratory pigment in man?
[A] Haemocyanin
[B] Haemoerythrin
[C] Haemoglobin
[D] b-Carotene
[C] Haemoglobin
Notes:
A respiratory pigment is a molecule, such as haemoglobin in humans, that increases the oxygen carrying capacity of the blood. The four most common invertebrate respiratory pigments are haemoglobin, haemocyanin, haemerythrin and chlorocruorin.
7. Chlorophyll was first isolated and named by ____:
[A] Chlorophyll
[B] Pelletier
[C] Caventou
[D] Caventou and Pelletier
[D] Caventou and Pelletier
Notes:
Chlorophyll was first isolated and named by Joseph Bienaimé Caventou and Pierre Joseph Pelletier in 1817. It is a chemical found in the chloroplasts of plants that allows the plant to absorb light. Energy from the light is used in photosynthesis to make glucose.
8. Commercially valued cork is obtained from ____:
[A] Quercusuber
[B] Cycas
[C] Cedrus Deodara
[D] Ficus
[A] Quercusuber
Notes:
Cork is a prime-subset of bark tissue that is harvested for commercial use primarily from Quercus suber. It is endemic to the Mediterranean region. Cork is composed of suberin, a hydrophobic substance and, because of its impermeable, buoyant, elastic, and fire retardant properties, it is used in a variety of products, such as wine stoppers.
9. On an average how many million red blood cells are present in a healthy human adult man per mm3 of blood?
[A] 1.5 – 2
[B] 2 – 2.5
[C] 5 – 5.5
[D] 9 – 9.5
C [5 – 5.5]
Notes:
The primary function of the red blood cells, or erythrocytes, is to carry oxygen from the lungs to body tissues and to transfer carbon dioxide from the tissues to the lungs. The RBC is a count of the number of red blood cells per cubic millimeter of blood. Newborns: 4.8 – 7.2 million Adults: (males): 4.6 – 6.0 million.
10. In cactus, the spines are the modified ____.
[A] Stem
[B] Buds
[C] Leaves
[D] Stipulse
[C] Leaves
Notes:
Most cactus morphologists have concluded that cactus spines are modified leaves. They are wholly transformed leaves that protect the plant from herbivores, radiate heat from the stem during the day, and collect and let drip condensed water vapour during the cooler night.