mocks - random topics

Question 1

viruses are _____ (cellular or acellular)

Answer 1

acellular

Question 2

viruses are acellular. what does acellular mean?

Answer 2

they are not a cell and not alive

Question 3

why are viruses acellular?

Answer 3

they can’t reproduce on their own

Question 4

how do viruses replicate?

Answer 4

utilise other HOST cells

Question 5

what is the structure of a virus?

Answer 5

1. attachment proteins - attach to host cell
2. protein coat - ‘capsid’
3. genetic material - core of DNA or RNA

Question 6

what are the 2 types of cell division in eukaryotes?

Answer 6

mitosis and meiosis

Question 7

what are the 2 types of cell division in eukaryotes?

Answer 7

mitosis and meiosis

Question 8

what is mitosis and what is it needed for?

Answer 8

cell divison - needed for growth of organisms and repairing damaged tissues

Question 9

what are the 4 stages of mitosis?

Answer 9

Prophase, metaphase, anaphase, telophase

Question 10

what happens in prophase in mitosis?

Answer 10

1. nuclear envelope breaks and chromosomes become visable
2. centrioles start to move to opposite ends of the cell -> forming spindles

Question 11

what happens in metaphase in mitosis?

Answer 11

1. chromosomes line up along the equator of the cell
2. chromosomes become attached to the spindles by their centromere (centre of chromosome)

Question 12

what happens in anaphase in mitosis?

Answer 12

1. centromeres divide - making sister chromatids (V shape)
2. spindles contract pulling chromatids to opposite poles of the cell

Question 13

what happens in telophase in mitosis?

Answer 13

1. chromatids reach opposite poles on spindle and unravel to become long and thin (now called chromosomes again)
2. nuclear envelope forms around each group of chromosomes
3. cytoplasm starts to divide

Question 14

what happens in cytokinesis?

Answer 14

1. cytoplasm divides and 2 genetically identical daughter cells are produced
2. mitosis is complete and daughter cells start interphase ready for another round of mitosis

Question 15

what is the structure of chromosomes?

Answer 15

1. 2 identical chromatids
2. centromere
3. DNA molecule - string like DNA coiled up into a compact structure called histones

Question 16

what are histones and where are they found?

Answer 16

long strings of DNA coiled up into a compare structure
in chromosomes

Question 17

what is cellulose made from?

Answer 17

straight, unbranched chains of beta glucose

Question 18

what is a condensation reaction?

Answer 18

formation of a chemical bond between 2 monomers

Question 19

what bond is formed in a condensation reaction?

Answer 19

1,4 or 1,6 glycosidic bond

Question 20

where is cellulose found and what is its function?

Answer 20

in the cell wall of plants - to give the cell strength and structure

Question 21

what is starch made up of?

Answer 21

2 polysaccharide chains;
amylose
amylopectin

Question 22

where is starch found and what is its function?

Answer 22

in plant cells - compact and a good storage molecule

Question 23

what is the primary structure of protein?

Answer 23

‘basic chain’ - sequence of amino acids

Question 24

what is the secondary structure of protein?

Answer 24

polypeptide chains fold into either an alpha or beta helix - held by hydrogen bonds

Question 25

what is the tertiary structure of proteins?

Answer 25

amino acids differ due to their R groups, bonds are formed; - hydrogen - ionic - disulfide bridges

Question 26

what is the quaternary structure of protein? give an example

Answer 26

2 or more polypeptide chains that interact with each other. eg. haemoglobin

Question 27

what is osmosis?

Answer 27

the net movement of water molecules from a region of high water potention to a region of low water potential, through a partically permeable membrane

Question 28

what does high water potential mean?

Answer 28

high volumes of water to give away

Question 29

what does it mean if the water potential is more negative?

Answer 29

the more concentrated the solution

Question 30

what is the lowest water potential?

Answer 30

0 kPa (pure water)

Question 31

how is water potential measured?

Answer 31

kilopascals (kPa)

Question 32

what does a lower water potential mean?

Answer 32

the less concentrated it is

Question 33

what is active immunity?

Answer 33

when the body stimulates and immune response, antibodies and memory cells are made

Question 34

what is passive immunity?

Answer 34

where the body recieves ready-made antibodies and no memory cells are created

Question 35

what is natural active immunity? give an example

Answer 35

when the body is stimulated to make antibodies and memory cells - more antibodies will be made in the 2nd response. eg. common cold

Question 36

what is artificial natural immunity? give an example

Answer 36

when an antigen is injected into the body but body still stimulates an immune response. eg. vaccination

Question 37

what is natural passive immunity?

Answer 37

when a baby recieves antibodies from a mother after birth - baby has immunity to same diseases as mother

Question 38

what is artifical passive immunity? give an example

Answer 38

body recieves ready made antibodies and no memory cells are produced. eg. tetanus jab

Question 39

briefly explain how the ELISA test works (HIV)

Answer 39

1. HIV antigens placed on surface (glass slide) 2. if person is HIV+ they will have HIV specific antigens in their blood - antibodies bind to antigen 3. wash slide 4. secondary antibodies added with enzyme attached - specific to the first antibodies 5. slide is washed 6. add the enzymes liquid substrate to slide; colour change if positive (yellow -> blue)

Question 40

why do you need to wash the slide in an ELISA test?

Answer 40

to wash away any unbound antibodies

Question 41

if the ELISA test is positive, what is the colour change?

Answer 41

from yellow to blue