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4

Chromosomes having equal or almost equal arms are called

A. metacentric

B. acrocentric

C. polycentric

D. acentric.

Correct Answer :

A. metacentric


Centromeres consist of a complex combination of proteins and DNA. They are essential to the division and ensure the accurate segregation of chromosomes. Metacentric chromosomes have the centromere in the centre, such that both sections are of equal length. Human chromosome 1 and 3 are metacentric.

Related Questions

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4

Extension of plasma membrane in prokaryotic cell is

A. mesosome

B. haploid

C. ribosome

D. none of these

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4

Which of the following statements are correct?

A. Na+/K+ pump is an example of active transport.

B. In plant cells lipid like steroidal hormones are synthesized in SER.

C. In plant cells, the vacuoles can occupy up to 10% of the volume of the cell.

D. Chlorophyll and leucoplast are responsible for trapping light energy essential for photosynthesis.

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4

The following diagram represents a structure chromosome.
Identify the structures marked as A, B and C.

A. A - Satellite, B - Primary constriction, C - Acrocentric

B. A - Satellite, B - Secondary constriction, C - Metacentric

C. A - Satellite, B - Centromere, C - Telocentric

D. A - Satellite, B - Centromere, C - Submetacentric

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4

Match column-I with column-II and select the correct option.
Column - IColumn - II
A. Golgi apparatusI. Storage
B. MitochondriaII. Photosynthesis
C. VacuolesIII. Transport
D. GranaIV. Secretion
..V. Respiration

A. A - IV, B - V, C - I, D - II

B. A - I, B - II, C - IV, D - III

C. A - IV, B - I, C - II, D - III

D. A - I, B - II, C - III, D - IV

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4

You are asked to examine a cell using a powerful light microscope. The image you see has a clearly defined nucleus and mitochondria. It also has a large central vacuole and chloroplasts. From what group of organisms did this cell most likely come?

A. Bacteria

B. Protists

C. Fungi

D. Plants

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4

Which one of the following combination is mismatched?

A. Glycocalyx May be capsule or slime layer

B. Pili Reproduction

C. Cell wall Protective, determines shape, prevents from bursting

D. Flagella, pili and fimbriae Surface structures of bacterial cell

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4

Study the following statements on cilium or flagellum and answer the question.
  1. Cilium / Flagellum contains an outer ring of nine doublet microtubules surrounding two singlet microtubules.
  2. Cilia are smaller which work like oars, causing the movement of either the cells or surrounding fluid.
  3. Flagella are comparatively longer and responsible for cell movement.
  4. Cilium and flagellum are covered with plasma membrane.

Which of the above statements are correct?

A. (i) and (ii)

B. (i), (ii), (iii) and (iv)

C. (i) and (iv)

D. (ii) and (iii)

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4

Lysosomes contain

A. carbohydrates

B. hormones

C. nucleic acids

D. hydrolases.

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4

Polysome is a chain of

A. oxysomes

B. sphaerosomes

C. ribosomes

D. dictyosomes

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4

Which one of the following cellular parts is correctly matched with their characters ?

A. Centrioles Sites for active RNA synthesis.

B. Lysosomes Optimally active at a pH of about 8.5.

C. Thylakoids Flattened membranous sacs forming the grana of chloroplasts.

D. Ribosomes Those on chloroplasts are larger (80S) while those in the cytoplasm are smaller (70S).

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4

Prokaryotic and eukaryotic flagella differ in the

A. type of movement and placement.

B. location and mode of functioning.

C. microtubular structure and function.

D. microtubular organization and type of movement.

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4

Choose the wrong statements regarding bacterial cell
  1. Glycocalyx is the outermost envelope in bacteria.
  2. The glycocalyx could be a loose sheath called capsule.
  3. The glycocalyx may be thick and tough called slime layer.
  4. A special structure formed by the plasma membrane is called mesosome.
  5. Small bristle like fibres sprouting out of the cell are called fimbriae.

A. (i) and (iii)

B. (i) and (ii)

C. (ii) and (iii)

D. (i) and (iv)

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4

Active transport across biomembrane involves

A. production of ATP

B. requirement of energy

C. production of toxin

D. release of energy

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4

Identify the components labelled A, B, C and D in the given section of cilia/flagella showing different parts. Choose the option which shows the correct labelling of parts.

A. A Plasma membrane, B Interdoublet bridge, C Central microtubule, D Radial spoke

B. A Plasma membrane, B Arm, C Central microtubule, D Radial spoke

C. A Plasma membrane, B Interdoublet bridge, C Hub, D Radial spoke

D. A Plasma membrane, B Interdoublet bridge, C Hub, D Arm

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4

According to widely accepted fluid mosaic model cell membranes are semi-fluid, where lipids and integral proteins can diffuse randomly. In recent years, this model has been modified in several respects. In this regard, which of the following statements is incorrect?

A. Proteins in cell membranes can travel within the lipid bilayer.

B. Proteins can also undergo flip-flop movements in the lipid bilayer.

C. Proteins can remain confined within certain domains of the membrane.

D. Many proteins remain completely embedded within the lipid bilayer.

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4

Who proposed the theory that Cells arise only from the pre-existing cells?

A. Mohl

B. Virchow

C. Haeckel

D. Brown

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4

Which one of the following pairs is not correctly matched?

A. Cristae The tubular structure formed by the folding of the inner membrane of the mitochondrion.

B. Plasmodesmata The membrane surrounding the vacuole in plants.

C. Grana Membrane bound discs in chloroplasts that contain chlorophylls and carotenoids.

D. Middle lamella Layer between adjacent cells walls in plants derived from cell plate.

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4

The given diagram shows the sectional view of a mitochondrion.

Identify the parts labelled as A, B, C, D & E

A. A - Outer membrane, B - Inner membrane, C - Matrix, D - Inter- membrane space, E - Crista

B. A - Outer membrane, B - Inner membrane, C - Intermembrane space, D - Matrix, E - Crista

C. A - Outer membrane, B - Inner membrane, C - Matrix, D - Crista, E - Inter - membrane space

D. A - Outer membrane, B - Inner membrane, C- Crista, D - Matrix, E - Inter-membrane space

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4

Nucleolus is

A. rounded structure found in cytoplasm near nucleus.

B. rounded structure inside nucleus and having rRNA.

C. rod-shaped structure in cytoplasm near the nucleus.

D. none of the above.

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4

In which method of transport, plasma membrane does not require carrier molecule?

A. Active transport

B. Facilitated diffusion

C. Simple diffusion

D. Na+ K+ pump

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4

Which one of the following organelle given below is correctly matched with its function ?

A. Golgi apparatus Protein synthesis

B. Golgi apparatus Formation of glycolipids

C. Rough endoplasmic reticulum Protein synthesis

D. Rough endoplasmic reticulum Formation of glycoproteins

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4

Basal bodies are associated with the formation of

A. phragmoplast

B. cilia and flagella

C. cell plate

D. kinetochore

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4

Active transport differs from passive transport in that active transport

A. requires energy.

B. always requires input of ATP.

C. moves molecules against a concentration gradient.

D. both (a) and (c)

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4

The best way to identify a cell as either prokaryotic or eukaryotic is to determine whether

A. it came from a single-celled or multicellular organism.

B. it has a nucleus.

C. it has a plasma membrane.

D. it has cytosol.

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4

Match column-I (cell organelle) with column-II membrane and select the correct option from the codes given below.
Column-IColumn-II
A. MitochondriaI. Without membrane
B. LysosomesII. Single membrane
C. RibosomesIII. Double membrane

A. A - I, B - II, C - III

B. A - III, B - I, C - II

C. A - III, B - II, C - I

D. A - II, B - III, C - I

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4

Which of the following terms is not correctly matched with its feature?

A. Osmosis Movement of water by diffusion.

B. Nucleoplasm Site of active synthesis of ribosomal RNA.

C. Mesosome Infolding of cell membrane and characteristics of eukaryotes.

D. Pili Elongated tubular surface structures (made of special protein) of bacteria.

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4

Centrifugation of a cell results in the rupture of the cell membrane and the contents compacting into a pellets in the bottom of the centrifuge tube. Bathing this pellet with a glucose solution yields metabolic activity including the production of ATP. One of the contents of this pellet is most likely which of the following?

A. Cytosol

B. Mitochondria

C. Lysosomes

D. Golgi bodies

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4

Centrioles and centrosomes occur in the cells of

A. green plants

B. animals

C. bacteria and cyanobacteria

D. both (b) and (c)

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4

In prokaryotes, chromatophores are

A. specialized granules responsible for colouration of cells

B. structures responsible for organizing the shape of the organism.

C. inclusion bodies lying free inside the cells for carrying out various metabolic activities.

D. internal membrane system which becomes extensive and complex in photosynthetic bacteria.

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4

Which of these is wrongly matched?

A. Chloroplasts Chlorophyll

B. Elaioplasts Starch

C. Chromoplasts Carotenoids

D. Amyloplasts Carbohydrates