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Flashcards in dna and genetics Deck (43)
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1

what is dna

dna is a complex molecule that determines the characteristics of most living things

2

when was dna discovered and who discovered it

in 1953
james Watson and Francis crick

3

what is the structure of dna

dna has the same structure in all organisms in that it is made up of smaller molecules called nucleotides
phosphate
deoxyribose sugar - base

4

what are the nitrogen bases

they pair up to form the rungs. the four bases are adenine, thymine, guanine and cytosine

5

what is a nucleotide

they are the parts that make up dna. they have three parts; phosphate group, deoxyribose sugar and one of the four nitrogen rich bases (a, t, g, or c)

6

what are the complementary base pairs

adenine+thymine and guanine+cytosine

7

who is Rosalind Franklin

she is a British chemist who is best known for her role in the discovery of the structure of dna

8

who is Maurice Wilkins

heis a biophysicist who was well known for his contributions to the discovery of dnas molecular structure
he won the 1962 Nobel prize

9

what can you do with dna

genetic testing, species identification, paternity, research, transgenic organisms

10

chromosomes are...

long, thin, thread-like structures found in the nuclei of all cells in the human body containing a nucleus (eukaryotic)

11

chromosomes are made up of...

dna molecule wrapped around proteins

12

chromosome number refers to...

the number of chromosomes in the human body. there are 46 chromosomes and two of them are sex chromosomes

13

what are the chromosomes called that don't determine the sex

autosome

14

how many chromosomes do people with down syndrome have

47

15

karyotype...

shows the pairs if chromosomes for a human cell

16

genes

sections of dna arranged along the dna
the order of bases and the number of bases will vary between genes
bases or codes contain instructions for particular characteristics for the person

17

xx

female

18

xy

male

19

how many genes on a chromosome

ranges from 200 to 2000

20

what is the molecule that connects the rungs to the upright molecules

sugar

21

what are the molecules that make the uprights of the ladder

phosphate and sugar

22

what are the rungs of the ladder made by

complementary base pairing : a-t rungs and g-c rungs

23

a=

adenine

24

t=

thymine

25

g=

guanine

26

c=

cytosine

27

what is a nucleotide

the small molecules in dna are called nucleotides. all of the nucleotides in dna have the same structure and they consist of phosphate group, deoxyribose sugar and a nitrogen rich base.

28

what is the upright of the dna structure?

backbone

29

what is it called when the chromosome is short and fat

coiling

30

what is another name for a double helix

chromatid

31

how many hydrogen bonds are in adenine and thymine

2

32

how many hydrogen bonds do guanine and cytosine have

3

33

what was the materials used in the dna extraction experiment

kiwi fruit
gauze pieces
test tube
measuring cylinder
cold ethanol
salt
detergent
glass rod
spatula
ice bath

34

describe the dna appearance that was extracted during the experiment

it looked like cotton and was very easy to move in the liquid

35

procedure and function of dna extraction

crush the kiwi fruit- break open the cells
add detergent- dissolve the fat part of the cell wall and nuclear membrane
add salt- break up the protein chains that bind around the dna
pour in cold ethanol- precipitate dna from the mixture

36

primary examples

gender

37

secondary examples

voice

38

genetic code

is an instruction for making proteins

39

how do genes become different

due to the order and number of bases

40

what do autosomes do

functioning of organs
hair colour
hair type-curly, straight
eye colour

41

how many pairs of chromosomes do humans have

23 pairs with one pair being the sex cells

42

how many chromosomes are in cells

sex cells-23 chromosomes-half of total
body cells-46 chromosomes-44 are autosomes and 2 are sex chromosomes

43

when a double helix is about to divide what does it do

each double helix coils around and around until it is short and fat.