Category: Class 11 Biology Objective Questions

Biology Multiple Choice Questions on “Biological Classification – Protista – 1”.

1. Protists survive in ________
a) dry desert
b) aquatic regions
c) dry mountains
d) hot hills
Answer: b
Clarification: Protists survive in aquatic regions. They can either survive in fresh water lakes, large oceans, deep seas and marshy areas etc. This is because their body is adapted to survive in areas with low oxygen concentration.

2. Which among the following comprises of animal like protists?
a) Protozoans
b) Chrysophytes
c) Slime molds
d) Dianoflagellates
Answer: a
Clarification: Since, Protozoans are mobile and can ingest food into their body they resemble animals. Some of the protozoans follow holozoic nutrition like that of animals. Therefore, Protozoans are animal like protists.

3. Diatoms are grouped under _________
a) Chrysophytes
b) Protozoans
c) Dianoflagelletes
d) Euglenoids
Answer: a
Clarification: Diatoms are grouped under Chrysophytes. Chrysophytes comprise of golden algae, diatoms and plant like protists etc. It’s because of the golden-yellow color of the species they are named as Chrysophytes.

4. Cell wall in diatoms is made of _______
a) Chitin
b) Pectin
c) Silica
d) Cellulose
Answer: c
Clarification: Cell wall in diatoms is made up of Silica. It’s a double shelled cell wall that fits exactly into each other like the lid of a box. Cell wall of diatoms remains in the earth even after they die and accumulate to form diatomaceous earth.

5. Diatomaceous earth can be used as a pest control because _________
a) it is porous
b) it contains silica which is poisonous for pests when eaten and therefore they die
c) it snatches out lipids from the outermost waxy layer of pests called cuticle and makes them dry which results in their death
d) it acts as anesthesia when given in minor quantities but pests die when large quantities are in taken
Answer: c
Clarification: Diatomaceous earth is used in pest control and grain storage. This is because they are abrasive in nature which snatches out lipids from the outermost layer of pests called cuticle and makes them dry which results in their death.

6. Diatoms store food as _______
a) Starch
b) Glucose
c) Oil
d) Fructose
Answer: c
Clarification: Diatoms store food as oil. Plants store their food as starch. Diatoms are the main food producing bodies in oceans. They prepare food by photosynthesis.

7. Chrysophytes contain chlorophyll or carotene or xanthophyll in them. Their cell wall is rigid and is made up of chitin.
a) True
b) False
Answer: b
Clarification: Chrysophytes contain chlorophyll or carotene or xanthophyll in them. Chrysophytes attain color due to these pigments present in them. Their cell wall is rigid and is made up of Cellulose/ Pectin/ Silica.

8. Cell wall in dianoflagelllates contain _______
a) Chitin
b) Cortex
c) Silica
d) Pectin
Answer: b
Clarification: Dianoflagellates have a complex cell wall made up of cortex. They also possess light sensitive organelle in their cell. Eye spot is found in some of them. Erythropsidium is known to have smallest eye.

9. Dianoflagellates contain ________
a) two flagella with both being transversal
b) two flagella with both being longitudinal
c) two flagella with lone being longitudinal and other being transversal
d) three flagella with one being along x-axis, other being along y-axis and the third one being along z-axis
Answer: c
Clarification: Dianoflagellates contain two flagella with lone being longitudinal and other being transversal. These two flagella help them for their movement and rotation.

10. Dianoflagellates are plant like protists.
a) True
b) False
Answer: b
Clarification: Dianoflagellates are neither plant nor animal like protists. This is because they perform both photosynthesis and locomotion. Therefore, they are neither plants nor animals.

11. What is red tide?
a) Accumulation of cell wall deposits of red algae is called red tide
b) Accumulation of red blood cells in water
c) Coloration of water due to rapid multiplication of red dianoflagellates
d) Spread of chrysophytes due to rapid reproduction
Answer: c
Clarification: Red tide is the coloration of water due to very rapid multiplication of red dianoflagellates. Chemicals released due to this rapid growth are harmful for aquatic life.

12. Which among the following is responsible for red tide?
a) Gonyaulax
b) Udinium
c) Noctiluca
d) Golden algae
Answer: a
Clarification: Red tide is the coloration of water due to very rapid multiplication of red dianoflagellates like Gonyaulax. Chemicals released due to this rapid growth are harmful for aquatic life.

13. Which among the following belong to plankton?
a) Dianoflagellates
b) Chrysophytes
c) Euglenoids
d) Protozoans
Answer: b
Clarification: Chrysophytes are found in aquatic habitats. They are present in fresh water as well as marine. Chrysophytes Are microscopic in nature and float in water currents like planktons.

14. Protists are unicellular eukaryotes.
a) True
b) False
Answer: b
Clarification: All the unicellular eukaryotes are placed in Protista. But all protists are not unicellular. There are few protists that are multi-cellular. But all the protists are eukaryotic organisms.

15. Desmids belong to ________
a) Dianoflagellates
b) Chrysophytes
c) Euglenoids
d) Protozoans
Answer: b
Clarification: Chrysophytes comprise of diatoms and golden algae (desmids). Desmids are unicellular eukaryotes and can prepare their own food by photosynthesis. Desmids reproduce both by sexually and asexually.

Botany Question Bank on “Flowering Plants Morphology – Fruit and the Seed-2”.

1. Dicotyledon seeds have two seed leaves.
a) True
b) False
Answer: a
Clarification: Dicotyledon seeds have two seed leaves. The word cotyledon means seed leaves. When a dicotyledonous seed germinates it initially gives rise to two seed leaves whereas in monocotyledonous seed only a single leaf arises.

2. Which among the following is incorrect about structure of the seed?
a) Testa and tegmen are the two layers of a seed coat
b) Testa and tegmen are closely attached that they can’t be separated unless soaked in water
c) Seed coat provides protection to the embryo
d) Testa is the thin inner layer and tegmen is the thick outer layer of a seed coat
Answer: d
Clarification: Testa and tegmen are the two layers of a seed coat. These are so closely attached that they can’t be separated unless soaked in water. Testa is the thick outer layer and tegmen is the thin inner layer of a seed coat .Seed coat provides protection to the embryo.

3. A scar on seed coat through which seed is attached to the fruit is called ________
a) Cotyledons
b) Seed coat
c) Hilum
d) Micropyle
Answer: c
Clarification: A scar on seed coat through which seed is attached to the fruit is called Hilum. The hilum on a bean seed is called an eye. It marks the former place of attachment of a seed.

4. Which among the following is not correct about embryo inside the seed?
a) An embryo contains cotyledons, radicle and plumule
b) Cotyledons store food and provide nourishment to the developing plumule and radicle
c) A plumule develops into roots
d) Cotyledons are also called as seed leaves
Answer: c
Clarification: An embryo contains cotyledons, radicle and plumule. Cotyledons store food and provide nourishment to the developing plumule and radicle. A plumule develops into roots. Cotyledons are also called as seed leaves.

5. Endosperm provides nourishment to a developing embryo and cotyledons provide nourishment to the developing radicle and plumule.
a) True
b) False
Answer: a
Clarification: Endosperm provides nourishment to a developing embryo and cotyledons provide nourishment to the developing radicle and plumule. Endosperm sometimes can be completely digested and absorbed before the seed gets detached.

6. Which among the following is incorrect about structure in a monocotyledon seed?
a) A monocotyledonous seed mainly comprises of seed coat, endosperm and aleurone layer
b) Seed coat is due to fusion of pericarp
c) Endosperm comprises of starch required for the nourishment of the endosperm
d) Special tissue surrounding the endosperm is called the seed coat
Answer: d
Clarification: A monocotyledonous seed mainly comprises of seed coat, endosperm and aleurone layer. Seed coat is due to fusion of pericarp. Endosperm comprises of starch required for the nourishment of the endosperm. Special tissue surrounding the endosperm is called the aleurone laer.

7. A single cotyledon is also termed as __________
a) Scutellum
b) Aleurone
c) Epicarp
d) Endocarp
Answer: a
Clarification: A single cotyledon i.e. a monocotyledon is also termed as scutellum. A scutellum consists of the embryonic shoot called plumule and the embryonic root called radicle. They get their nourishment from the endosperm in the initial stage and from the cotyledons during their development into a shoot system.

8. Embryonic shoot is covered by a protective layer called _________
a) Coleoptile
b) Coleorrhiza
c) Scutellum
d) Aleurone
Answer: a
Clarification: A scutellum contains an embryonic shoot and an embryonic root called as plumule and radicle respectively. The embryonic shoot is covered by a protective layer called coleoptile.

9. Embryonic root is covered by a protective layer called ________
a) Coleoptile
b) Coleorrhiza
c) Scutellum
d) Aleurone
Answer: b
Clarification: A scutellum consists of an embryonic root and an embryonic shoot called as radicle and plumule respectively. Embryonic root is covered by a protective layer called coleorrhiza.

10. Which among the following is correct about the structure of a monocotyledon?

a) a-Endosperm; b-Seed coat; c-Aleurone layer; d-Scutellum; e-Coleoptile; f-Radicle; g-Coleorhiza
b) a-Scutellum; b-Seed coat; c-Aleurone layer; d-Endosperm; e-Coleoptile; f-Plumule; g-Coleorhiza
c) a-Scutellum; b-Seed coat; c-Aleurone layer; d-Endosperm; e-Coleorhiza; f-Plumule; g-Coleoptile
d) a-Endosperm; b-Seed coat; c-Aleurone layer; d-Scutellum; e-Coleorhiza; f-Plumule; g-Coleoptile
Answer: a
Clarification: Endosperm provides nourishment to the embryo. Seed coat protects the embryo. Aleurone layer surrounds the endosperm and gives protection. A monocotyledon is also called as Scutellum. Coleoptile protects the plumule and coleorhiza protects the radicle.

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Biology Multiple Choice Questions on “Cell – Nucleus”.

1. Which scientist coined the term chromatin?
a) Robert Koch
b) Louis Pasteur
c) Robert Brown
d) Alexander Fleming
Answer: d
Clarification: Sir Alexander Fleming was a Scottish scientist, known for his work on microbiology and medicine. The material in the nucleus which he stained by basic dyes was coined by him as chromatin.

2. What is the space between the two membranes of the nuclear envelope known as?
a) Reticular space
b) Intra – membrane space
c) Perinuclear space
d) Somatic space
Answer: c
Clarification: Electron microscopy has revealed that the nuclear envelope consists of two parallel membranes with a space between them called the perinuclear space. It forms a barrier between the materials present inside the nucleus and that of the cytoplasm.

3. Which of these cells lack a nucleus?
a) Thrombocytes in humans
b) Lymphocytes of primates
c) Sieve tube cells of vascular plants
d) Epithelial cells
Answer: c
Clarification: Some cells such as the red blood cells or the erythrocytes of humans and the sieve tube cells of vascular plants lack a nucleus in their mature cells. Leukocytes and thrombocytes possess a nucleus.

4. Which of these is an important constituent of the nuclear matrix?
a) Chromatin
b) Ribosomes
c) Mitochondria
d) Centrosomes
Answer: a
Clarification: The nuclear matrix or the nucleoplasm contains the nucleolus and chromatin. The nucleoli are spherical structures present in the nucleoplasm and the chromatin is present along with it.

5. What is the site of rRNA synthesis within a cell?
a) Chromatin
b) Nucleolus
c) Perinuclear space
d) Centrosomes
Answer: b
Clarification: The nuclear matrix or the nucleoplasm contains the nucleolus and chromatin. The nucleolus is the site for active ribosomal RNA or rRNA synthesis. The nucleolus is not bound by a membrane.

6. Which of these organelles are not membrane bound?
a) Mitochondria
b) Endoplasmic reticulum
c) Nucleolus
d) Lysosome
Answer: c
Clarification: The nucleus contains the nucleolus which is not a membrane-bound organelle. The mitochondria, the endoplasmic reticulum, and lysosomes are present in the cytosol. They are membrane-bound organelles of the cell.

7. Which is the primary constriction for every visible chromosome?
a) Centromere
b) Ribosomes
c) Kinetochores
d) Histones
Answer: a
Clarification: Every visible chromosome has two sister chromatids which are constricted together at a point known as the centromere. During mitosis, the spindle fibres attach to the chromosomes via the centromere.

8. Which form of chromosome has two equal arms?
a) Telocentric chromosome
b) Acrocentric chromosome
c) Sub – metacentric chromosome
d) Metacentric chromosome
Answer: d
Clarification: Based on the position of the centromere, the chromosomes can be classified into four types. The metacentric chromosome has its centromere in the middle, thus forming two equal arms of the chromosome.

9. Which type of chromosome has its centromere at its tip?
a) Acrocentric chromosome
b) Telocentric chromosome
c) Sub – metacentric chromosome
d) Metacentric chromosome
Answer: b
Clarification: Based on the position of the centromere, the chromosomes can be classified into four types. In telocentric chromosomes, the centromere is located at the proximal end or the tip of the chromosome.

10. The nucleolus is the site of rRNA synthesis. True or false?
a) True
b) False
Answer: a
Clarification: The nucleus contains the nucleolus which is not a membrane-bound organelle. The nucleus also contains chromatin. The nucleolus is the site of active ribosomal RNA or rRNA synthesis.

11. Identify the structure.

a) Chromatin
b) DNA
c) Centromere
d) Kinetochore
Answer: d
Clarification: At the constriction between the arms of a chromosome lies disc shaped structures known as kinetochores. It is the site where spindle fibres attach during cell division to pull sister chromatids apart.

12. A few chromosomes have non-staining constrictions at a constant location. What are these constrictions called?
a) Cilia
b) Flagella
c) Satellite
d) Kinetochore
Answer: c
Clarification: Some chromosomes have secondary constrictions which are non – staining, apart from the centromere. They give the appearance of a small fragment. This small fragment is known as a satellite.

13. Identify the structure.

a) Cilia
b) Flagella
c) Satellite
d) Kinetochore
Answer: c
Clarification: Some chromosomes have secondary constrictions which are non-staining, apart from the centromere. They give the appearance of a small fragment. This small fragment is known as a satellite.

14. What are the disc shaped structures located on the sides of the centromere?
a) Kinetochores
b) Satellite cells
c) Flagella
d) Ribosomes
Answer: a
Clarification: Every chromosome has a primary constriction known as the centromere. The sides of the centromere contains disc shaped structures known as kinetochores.

15. What is the number of chromosomes present in an oocyte?
a) 46
b) 23
c) 21
d) 48
Answer: b
Clarification: A single human cell has approximately two metre long thread of DNA. This DNA is distributed among its forty-six (twenty-three pairs) chromosomes. Since, the oocyte is haploid, it contains 23 chromosomes.

Biology Question Papers for Medical Entrance Exams on “Biomolecules – Structure of Proteins-2”.

1. What type of helix is observed in proteins?
a) Left-handed helix
b) Parallel double helix
c) Antiparallel double helix
d) Right-handed helix
Answer: d
Clarification: The secondary structure of proteins is in the form of a single helix. It is formed by the folding of the primary structure. Anti-parallel double-stranded helix is found in DNA. Proteins always possess a right-handed helix.

2. Which of these statements is true about the secondary structure of proteins?
a) Secondary structure of protein occurs only in the form of helices
b) Protein helices are always double-stranded
c) Protein helices and right-handed
d) Entire primary structure of the protein is folded into a helix
Answer: c
Clarification: Protein helices are always right-handed. The secondary structure occurs in the form of helices and sheets. They are always single stranded and only parts of the protein chain is folded into helices.

3. Which of these structures is necessary for the activity of proteins?
a) Alpha–helix
b) Primary structure
c) Tertiary structure
d) Beta–sheet
Answer: c
Clarification: The tertiary structure is necessary for the activity of protein inside the body to perform various functions such as enzymatic activity, hormonal control, cell division and the normal development and maintenance of the body.

4. Which of these structures is three-dimensional?
a) Tertiary structure
b) Primary structure
c) Alpha–helix
d) Beta–sheet
Answer: a
Clarification: The primary structure of proteins consists of a long chain of amino acids. The secondary structure of proteins which consists of helices and sheets is also a two-dimensional structure. However, the tertiary structure of proteins is a three-dimensional structure.

5. Identify the level of organization of the polypeptide.

a) Quaternary
b) Secondary
c) Primary
d) Tertiary
Answer: b
Clarification: The given diagram shows an Alpha helix. Alpha helix is a type of secondary structure of proteins. Therefore, the level of organization of the given polypeptide chain is secondary. It is formed by the folding of the primary structure.

6. Which of these structures have more than one polypeptide chain?
a) Primary
b) Tertiary
c) Quaternary
d) Secondary
Answer: c
Clarification: Quaternary structures of proteins consist of more than one polypeptide chain or subunits. It is formed by the association and different arrangements of polypeptides chains with each other.

7. Which of these levels of organization does hemoglobin possess?
a) Quaternary
b) Tertiary
c) Secondary
d) Primary
Answer: a
Clarification: Hemoglobin possesses four subunits-two alpha subunits and two beta subunits. Since hemoglobin is made of more than one subunit or polypeptide chain, it possesses a quaternary structure.

8. How many subunits does human hemoglobin contain?
a) 2
b) 3
c) 6
d) 4
Answer: d
Clarification: Adult human hemoglobin is composed of four subunits – two alpha subunits and two beta subunits. Hemoglobin is an iron-containing metalloprotein present in red blood cells for gaseous transport.

9. How many types of subunits does hemoglobin possess?
a) 1
b) 4
c) 2
d) 3
Answer: c
Clarification: Adult human hemoglobin is composed of four subunits-two alpha subunits and two beta subunits. Two subunits are of alpha type while two subunits are of beta type. Hence, it has two types of subunits.

10. Tertiary structure gives a three-dimensional view of proteins. True or false?
a) True
b) False
Answer: a
Clarification: Tertiary structures are formed by the folding of primary structure and further folding of secondary structures. The tertiary structure hence formed gives us a three-dimensional view of the protein.

11. Identify the structure.

a) Primary structure
b) Quaternary structure
c) Secondary structure
d) Tertiary structure
Answer: d
Clarification: The structure labelled in the diagram is the tertiary structure. Tertiary structures are formed by the folding of the linear primary structure and by the further folding of secondary structures.

12. Identify the level of organization of the protein.

a) Primary
b) Tertiary
c) Quaternary
d) Secondary
Answer: c
Clarification: The given protein in the diagram has a quaternary level of organization. This can be understood by observing four subunits which are distinct from each other. It is the highest level of organization.

13. Which level of organization do beta sheets belong to?
a) Primary
b) Quaternary
c) Secondary
d) Tertiary
Answer: c
Clarification: Beta sheets and alpha helices are forms of the secondary level of organization of proteins.

14. In which of these structures of proteins can disulfide bonds be found?
a) Tertiary structure
b) Alpha helix
c) Beta sheet
d) Primary structure
Answer: a
Clarification: Tertiary structures are formed by the folding of the linear primary structure and by the further folding of secondary structures. These structures re three-dimensional and are characterized by interactions such as disulfide bonds.

15. How many beta subunits are present in human hemoglobin?
a) 1
b) 2
c) 3
d) 4
Answer: b
Clarification: Adult human hemoglobin is composed of four subunits-two alpha subunits and two beta subunits. Hemoglobin is an iron-containing metalloprotein which has a quaternary level of organization.

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