biology MCQs - 11th class Chapter 04 Mcqs

1

Who first discovered and named cells in 1665 by observing cork sections?

A

Theodor Schwann

B

Robert Hooke

C

Rudolph Virchow

D

Robert Brown

2

Which scientist reported the presence of the nucleus in the cell in 1831?

A

Lorenz Oken

B

Jean Baptist de-Lamarck

C

Robert Brown

D

Louis Pasteur

3

The principle 'Omnis cellula e cellula' (all cells arise from pre-existing cells) was hypothesized by whom?

A

Rudolph Virchow

B

August Weismann

C

Robert Hooke

D

Schleiden

4

The Fluid Mosaic Model describes the structure of the:

A

Cell wall

B

Cytoplasm

C

Plasma membrane

D

Nucleus

5

What is the chemical composition of the cell membrane?

A

60-80% lipids, 20-40% proteins

B

60-80% proteins, 20-40% lipids

C

90% carbohydrates, 10% lipids

D

50% proteins, 50% carbohydrates

6

The intake of solid particles by the cell membrane is termed as:

A

Pinocytosis

B

Exocytosis

C

Active transport

D

Phagocytosis

7

The strengthening material in the cell wall of prokaryotes is:

A

Cellulose

B

Chitin

C

Peptidoglycan

D

Lignin

8

The soluble part of the cytoplasm is called:

A

Protoplasm

B

Cytosol

C

Nucleoplasm

D

Endoplasm

9

Which organelle is involved in the synthesis of lipids and detoxification of harmful drugs?

A

Rough Endoplasmic Reticulum (RER)

B

Smooth Endoplasmic Reticulum (SER)

C

Golgi apparatus

D

Lysosome

10

Eukaryotic ribosomes are composed of which two subunits?

A

50S and 30S

B

60S and 40S

C

70S and 30S

D

50S and 40S

11

A group of ribosomes attached to a molecule of messenger RNA (mRNA) is known as a:

A

Polypeptide

B

Polysaccharide

C

Polysome

D

Polymer

12

Which organelle modifies, sorts, and packages proteins and lipids for secretion or delivery to other organelles?

A

Mitochondrion

B

Ribosome

C

Endoplasmic Reticulum

D

Golgi apparatus

13

Which organelle contains hydrolytic enzymes and is involved in phagocytosis and autophagy?

A

Peroxisome

B

Vacuole

C

Lysosome

D

Ribosome

14

Tay-Sachs disease is caused by the accumulation of what substance in brain cells?

A

Glycogen

B

Proteins

C

Lipids

D

Nucleic acids

15

Which organelles are specifically involved in the formation and decomposition of hydrogen peroxide?

A

Lysosomes

B

Glyoxysomes

C

Peroxisomes

D

Ribosomes

16

In plant seedlings, which organelle is responsible for converting stored fatty acids to carbohydrates?

A

Mitochondria

B

Chloroplasts

C

Peroxisomes

D

Glyoxysomes

17

The cytoskeletal fabric is formed of microtubules, microfilaments, and what other component?

A

Macrofilaments

B

Intermediate filaments

C

Cytosol fibers

D

Protein webs

18

Centrioles are composed of a cylindrical array of how many microtubule triplets?

A

Seven

B

Eight

C

Nine

D

Ten

19

Which organelle is known as the 'powerhouse of the cell'?

A

Nucleus

B

Chloroplast

C

Mitochondrion

D

Ribosome

20

The infoldings of the inner mitochondrial membrane are called:

A

Grana

B

Cristae

C

Thylakoids

D

Matrix

21

Which pigment-containing plastids are responsible for colors in flowers and fruits?

A

Chloroplasts

B

Leucoplasts

C

Chromoplasts

D

Protoplasts

22

Which part of the chloroplast contains the chlorophyll molecules and is the site of ATP formation?

A

Stroma

B

Envelope

C

Thylakoid membranes

D

Intergranum

23

A stack of thylakoids in a chloroplast is known as a:

A

Stroma

B

Granum

C

Crista

D

Matrix

24

The nuclear envelope is composed of how many membranes?

A

One

B

Two

C

Three

D

Four

25

Where are new ribosomes assembled within the nucleus?

A

Chromatin

B

Nucleoplasm

C

Nuclear pore

D

Nucleolus

26

A chromosome consists of two identical parts held together at the centromere, called:

A

Chromatins

B

Centrosomes

C

Sister chromatids

D

Kinetochores

27

How many chromosomes are found in a normal human body cell?

A

23

B

48

C

46

D

16

28

Organisms like bacteria and blue-green algae, which lack a membrane-bound nucleus, are called:

A

Eukaryotes

B

Protists

C

Fungi

D

Prokaryotes

29

Prokaryotic ribosomes are of which size?

A

80S

B

60S

C

70S

D

40S

30

The cell theory states that all organisms are composed of one or more:

A

Tissues

B

Organs

C

Molecules

D

Cells

31

In a compound microscope with a 10X ocular lens and a 40X objective lens, the total magnification is:

A

50X

B

100X

C

400X

D

500X

32

The process of separating cellular components by spinning them in a centrifuge is called:

A

Homogenization

B

Cell fractionation

C

Electrophoresis

D

Microscopy

33

Which structure is present in plant cells but absent in most animal cells?

A

Plasma membrane

B

Cell wall

C

Mitochondrion

D

Ribosomes

34

The process of a cell taking in liquid material by infolding of the cell membrane is called:

A

Phagocytosis

B

Exocytosis

C

Pinocytosis

D

Active transport

35

The middle lamella in plant cells is located between the:

A

Primary wall and secondary wall

B

Secondary walls of adjacent cells

C

Cytoplasm and primary wall

D

Primary walls of neighboring cells

36

The fungal cell wall primarily contains which substance?

A

Cellulose

B

Peptidoglycan

C

Chitin

D

Silica

37

The internal membrane system of the endoplasmic reticulum is made of sacs called:

A

Vesicles

B

Cisternae

C

Vacuoles

D

Tubules

38

The 'factory' for ribosome synthesis is the:

A

Cytoplasm

B

Golgi apparatus

C

Nucleolus

D

RER

39

The forming face of the Golgi apparatus is typically its:

A

Inner concave surface

B

Outer convex surface

C

Lateral side

D

Central stack

40

Glycogenosis type II is a storage disease caused by the absence of an enzyme that degrades:

A

Lipids

B

Proteins

C

Glycogen

D

Cellulose

41

Which cytoskeletal component is made of tubulin protein?

A

Microfilaments

B

Intermediate filaments

C

Microtubules

D

Myosin fibers

42

In which cells are centrioles typically absent?

A

Animal cells

B

Lower plant cells

C

Higher plant cells

D

Microorganisms

43

Mitochondria are considered self-replicating organelles because they contain their own:

A

Lysosomes and vacuoles

B

Golgi and ER

C

DNA and ribosomes

D

Centrioles and plastids

44

The central atom in a chlorophyll molecule is:

A

Iron (Fe++)

B

Magnesium (Mg++)

C

Calcium (Ca++)

D

Sodium (Na+)

45

Which type of plastid is colorless and functions to store food?

A

Chromoplasts

B

Chloroplasts

C

Leucoplasts

D

Amyloplasts

46

The darkly stained material within a non-dividing nucleus is called:

A

Chromosome

B

Centromere

C

Chromatin network

D

Nucleoplasm

47

The number of chromosomes in a fruit fly (Drosophila melanogaster) is:

A

46

B

48

C

16

D

8

48

The cell wall of plants is primarily made of:

A

Chitin

B

Peptidoglycan

C

Cellulose

D

Protein

49

In prokaryotes, the genetic material (DNA) is located in a region called the:

A

Nucleus

B

Nucleolus

C

Plasmid

D

Nucleoid