Cell

Question 1

how is the image magnified in a microscope

Answer 1

lenses refract the light in such way that the image of the specimen is magnified as it is projected into the eye or into the camera

Question 2

what are the 3 important parameters in microscopy

Answer 2

magnification, resolution and contrast

Question 3

what is magnification

Answer 3

is the ratio of an objects images size to real size

Question 4

how much can light microscope magnify

Answer 4

1000 to 1500

Question 5

what is resolution

Answer 5

is the measure of the clarity of the image and minimum distance 2 points can be separated & still be distinguished as 2 points

Question 6

whats the maximum resolution the light microscope can give

Answer 6

0.2 micrometer or 200 nano meters

Question 7

what is contrast

Answer 7

the difference in brightness between the light and dark areas of the image

Question 8

what does electron microscope use

Answer 8

it uses a beam of electrons

Question 9

is resolution inversely related to wavelength of light or electrons

Answer 9

yes

Question 10

how much resolution can electron microscope give

Answer 10

0.002 nm

Question 11

what is topography

Answer 11

the distribution of parts or features on the surface of or within an organ or organism

Question 12

what does SEM stand for

Answer 12

what does Scanning electron microscope

Question 13

does SEM show 3D

Answer 13

yes

Question 14

why do we use SEM

Answer 14

to study the the derailed topography

Question 15

how does SEM work

Answer 15

The electron beam scans the surface of the sample which is usually coated with a thin filament of gold. And these secondary electrons are detected by the device which translates the pattern into the Electronic signal in the video screen

Question 16

why do we use TEM

Answer 16

to study the internal structure of the cell

Question 17

what does TEM stand for

Answer 17

transmission electron microscope

Question 18

how does TEM work

Answer 18

TEM, the specimen has been stained with atoms of heavy metals, which attach to certain cellular structures, thus enhancing the electron density of some parts of the cell more than others.instead of using glasses both sem and TEM use electromagnets as lenses to bend pathways electrons

Question 19

what is the disadvantage of electron microscopes

Answer 19

method used to prepare the specimen kills the cell

Question 20

why is cell fractionation used

Answer 20

takes the cells apart and separate major organelles and other sub cellular structure

Question 21

are protists and fungi eukaryote

Answer 21

yes

Question 22

what does protist mean

Answer 22

a diverse group unicellular eukaryotes

Question 23

which domains consist of prokarytic cell

Answer 23

archea and bacteria

Question 24

list eukaryotic cell domain

Answer 24

plant, animal, fungi and protoctist

Question 25

what is plasma membrane

Answer 25

is the cell membranes

Question 26

is cell membrane permeable,

Answer 26

Yes

Question 27

what is cytosol

Answer 27

area of the cytoplasm that’s not held by organelles, (cytoplasm-organellles)

Question 28

whats is protoplasm

Answer 28

include the cytoplasm, nucleus and other organelles & its divided into cytoplasm and nucleoplasm

Question 29

what is cytoplasm

Answer 29

everything in the cell é membrane excluding the nucleus contains cytosol and organelles

Question 30

do all cells have chromosomes

Answer 30

Yes

Question 31

do all cells have ribosome

Answer 31

yes except virus

Question 32

where is th dna found in eukarytic cells

Answer 32

Nucleus

Question 33

where is the dna found in prokarytic cells

Answer 33

nucleoide

Question 34

whats is the typical diameter of bacteria

Answer 34

1-5 micrometer

Question 35

what is the typical eukarytic cell diameter

Answer 35

10-100 micrometer

Question 36

why does smaller organisms have greater surface area to volume ration

Answer 36

area is promotional to linear dimension squared whereas volume is proportional to cubic dimentional cube

Question 37

isn’t true that larger organism have bigger cells

Answer 37

no they have more cells in quantity t

Question 38

what is the average diameter of nucleus

Answer 38

6 micrometer

Question 39

what does nuclear envelope

Answer 39

it enclose the nucleus and separates from cytoplasm

Question 40

what are the nuclear double membrane made of

Answer 40

phospholipid bilayer

Question 41

Where is most of the genes in eukaryotic cell present

Answer 41

nucleus

Question 42

Which other place rather then nucleus can genes of eukaryotic cell be present

Answer 42

Chloroplast and mitocondria

Question 43

What is the average diameter of nucleus

Answer 43

5 micrometer

Question 44

What is the largest organelle

Answer 44

Nucleus

Question 45

What does nuclear envelope do

Answer 45

Encloses the nucleus separating the content form cytoplasm,

Question 46

What is the nuclear double membrane made of

Answer 46

Lipid bilayer with associated proteins,

Question 47

What is the diameters of pored between nuclear pores

Answer 47

100nm

Question 48

Is nuclear pore selective

Answer 48

Yes very selective

Question 49

How is the outer membrane of the nucleus continuous

Answer 49

They start forming Endoplasmic reticulum

Question 50

What are the things that can enter and leave the nuclear pore

Answer 50

Proteins, rna and large complexes of macromolecules

Question 51

What does nuclear lamina do

Answer 51

They maintain the shape of the nucleus by mechanically supporting the nuclear envelope.

Question 52

In the nucleus the dna is organized into discrete unit called ...

Answer 52

Chromosome

Question 53

Chromosome ARe made of?

Answer 53

Chromatin fibre n

Question 54

What happens to the chromosome when the cell divides

Answer 54

It condenses and is visible

Question 55

Can nucleoli be seen under light microscope

Answer 55

No

Question 56

What happens in the Nucleolus

Answer 56

Ribosomal rna or rRna is synthesized for the instruction of the dna

Question 57

What happens to the proteins imported from the cytoplasm to the nucleuolus

Answer 57

Assembled with the rRNA into large and small subunits of ribosome

Question 58

How does a ribosome form

Answer 58

The small and large subunits leave the nucleus through nuclear pore where they assemble into ribosome.

Question 59

Can a nucleus have more than one nucleolus

Answer 59

Yes

Question 60

Whta does the number of nucleolus depend on

Answer 60

Species and stage of reproductive cycle

Question 61

How does nucleus direct protein synthesis

Answer 61

It makes mRNA from dna, and exits the nucleus via nuclear pore, where the ribosome translates the mRNA into protein

Question 62

Are ribosomes organelle?

Answer 62

No

Question 63

Why aren’t ribosome organelles

Answer 63

Do not have a membrane bound organelles

Question 64

What are the 2 organelles that cells with high protein synthesis have

Answer 64

Prominent nucleoli and many ribosome

Question 65

Where are free ribosomes and bound ribosome present

Answer 65

The free ones are found in the cytosol and the membrane bound are found in Endoplasmic reticulum or nuclear envelope.

Question 66

Are bound and free ribosomes structurally identicle

Answer 66

Yes

Question 67

What happens to the protein made in free ribosomes

Answer 67

They mainly remain in the cytosol

Question 68

What happens or protein made in bound ribosome

Answer 68

Make protein destined for insertion into membrane for packaging within the organelles such as lysosome or for exportation from the cell