Topic 1 – Key Concepts in Biology-Cells And Microscopy

Question 1

state the two types of cell

Answer 1

eukaryotic (animals and plants) and prokaryotic

Question 2

what is difference between eurkaryotic and prokaryotic?

Answer 2

eukaryotic cell contains nucleus and membrane bound organelles. a prokaryotic bound organelle

Question 3

list components of both plants and animals

Answer 3

nucleus 
cytoplasm
cell membrane
mitochondria
ribosomes

Question 4

how is genetic information stored in eukaryotic cell

Answer 4

within nucleus arranged in chromsomes

Question 5

other then storing genetic information, what is the function of the nucleus?

Answer 5

controls cellular activites

Question 6

describe structure of cytoplasm

Answer 6

fluid component of cell

contain organelles enzymes dissolved ions and nutrients

Question 7

what is function of cell membrane

Answer 7

controls entry and exit of materials into and out of the cells

Question 8

what is the function of the mitochondria

Answer 8

sits of later stages of aerobic respiration in which ATP (Energy) is produced

Question 9

what is function of ribosomes

Answer 9

joins amino acids in a specific order during translation

Question 10

what organelles are found in plant cells only

Answer 10

large permanent vacuole
cell wall
chloroplasts

Question 11

what is cell wall made off

Answer 11

celluose

Question 12

what is function of cell wall?

Answer 12

provide strength

provide cell bursting when water enters by osmosis

Question 13

what does permanent vacuole contain?

Answer 13

solution of salts, sugars and organic acids

Question 14

what is function of permanent vacuole?

Answer 14

supporting cell, maintain its turgidity

Question 15

what is function of chlorplasts

Answer 15

site of photosynthsis

Question 16

when looking at a cell using light microscope why are chloroplasts green?

Answer 16

contain chlorophyll a green pigment

Question 17

list organelles found in prokaryotic cells

Answer 17

chromosomal DNA
Plasmid DNA
Cell wall
Cell membrane
ribosomes
flagella

Question 18

how is genetic information stored in prokaryotic cell?

Answer 18

found free within cytoplasm as:
chromosomal DNA
plasmid DNA

Question 19

What are plasmids?

Answer 19

small circular loops of DNA found free in cytoplasm and separate from main DNA
carry genes that provide genetic advantages e.g. antibiotic resistance

Question 20

what is the prokaryotic cell wall composed of?

Answer 20

peptidoglycan

Question 21

what is a flagellum

Answer 21

long rotating whip like protrusion, enables bacteria to move

Question 22

what is a haploid cell

Answer 22

cell contains single copy of each chromosome, 23 chromosomes in humans

Question 23

what are gamates

Answer 23

reproductive cells, haploid cells

Question 24

describe sexual reproduction in terms of chromosome number?

Answer 24

2 haploid gametes fuse

resulting embryo has 2 chromosomes for each gene and 2 copies of each allele dipolid

Question 25

describe how egg cells are adapted to their function

Answer 25

haploid nucleus contains genetic material mitochondria in cytoplasm produce energy for developing embryo cytoplasm contain nutrients for developing embryo cell membrane hardens after fertilisation, preventing entry of other sperm, ensuring zygote is diploid

Question 26

describe how sperm cells are adapted to their function

Answer 26

haploid nucleus contain genetic information tail enable movement mitochondria provide energy for tail movement acrosome contain enzymes that digest egg cell membrane

Question 27

where are ciliated epithelial found?

Answer 27

found lining the surface of structures such as respiratory tract and uterus.

Question 28

describe function of ciliated epithelial cells lining the airway

Answer 28

move in synchronised waves to beat mucus (dirt and pathogens) up to the back of throat where it can be swallowed.

Question 29

what is magnification

Answer 29

numbers of time bigger an image appears compared to size of speciman

Question 30

how can total magnification of an image be found from lens power?

Answer 30

total magnification= eyepiece lens magnification x objective lens magnification

Question 31

how can the magnification of an image be calculated?

Answer 31

size of image/size of specimen

Question 32

what is resolution?

Answer 32

smallest distance between 2 objects that can be distinguished

Question 33

how does a light microscope work?

Answer 33

passes beam of light through specimen which travel through eyepiece lens, allowing specimen to be observed.

Question 34

what are advantages of light microscopes?

Answer 34

inexpensive easy to use portable observe both dead and living organisms

Question 35

what is disadvantage of light microscopes?

Answer 35

limited resolution

Question 36

how does an electron microscope work?

Answer 36

uses beam of electrons which focused using magnets. electrons hit fluorescent screen which emits visible light, producing an image.

Question 37

name 2 types of electrons

Answer 37

transmission electron microscope (TEM) | scanning electron microscope (SEM)

Question 38

what is advantage of electron microscope?

Answer 38

greater magnification and resolution

Question 39

why do electron microscopes have greater have greater resolution and magnification?

Answer 39

use a beam of electrons which has shorter wavelength than photons of light

Question 40

how have electron microscopes enabled scientists to develop understanding of cells?

Answer 40

allow small sub cellular structures to be observed in detail | enable scientists to develop more accurate explanations about how cell structure relates to function

Question 41

what are disadvantages of electron microscope?

Answer 41

expensive large so less portable requires training to use only dead specimens can be observed.

Question 42

how do you convert m to mm?

Answer 42

x10^3

Question 43

how do you convert m to um

Answer 43

x10^6

Question 44

how do you convert m to nm?

Answer 44

x10^9

Question 45

how do you convert from m to pm?

Answer 45

x10^12

Question 46

write 0.005 in standard form

Answer 46

5x10^-3