DNA, genes and chromosomes

Question 1

what does prokaryote mean

Answer 1

before the nucleus

Question 2

prokaryotic DNA circular or linear

Answer 2

circular

Question 3

what DNA do prokaryotes contain

Answer 3

a single, circular chromosomal DNA molecules

Question 4

what is the single, circular chromosomal DNA in prokaryotes sometimes reffered to as

Answer 4

nucleoid

Question 5

what are plasmids

Answer 5

very small circular DNA molecules

Question 6

how many genes do plasmids contains

Answer 6

a few

Question 7

why are plasmids used

Answer 7

more accessible for proteins requires for a gene expression and therefore contain genes that are requires often, quickly and in emergencies

Question 8

where are genes for antibiotic resistance found

Answer 8

plasmids

Question 9

prokaryotic DNA protein association

Answer 9

not associated with any proteins

Question 10

eukaryotic DNA protein association

Answer 10

histone proteins

Question 11

what are chromosomes (eukaryotic) made of

Answer 11

one long, condensed DNA molecules associated with histone proteins

Question 12

role of histone proteins

Answer 12

organise and condense the DNA tightly to fit into the nucleus

Question 13

what are the other proteins (not histone) used for in eukaryotic chromosomes

Answer 13

enzymes used in copying and repairing DNA

Question 14

what is chromatin

Answer 14

tightly coiled combination of DNA and proteins

Question 15

what are chromatids and chromosomes made of

Answer 15

chromatin

Question 16

what happens during s phase of interphase

Answer 16

the DNA replicates to create two identical strands of DNA called chromatids joined together by a narrow region called the centromere

Question 17

what are sister chromatids

Answer 17

two chromatids that make up the double structure of a chromosome

Question 18

why is important sister chromatids are identical

Answer 18

key to cell division as one chromatid goes into one daughter cell and one to the other during mitosis ensuring daughter cells are genitally identical

Question 19

what is a chromatid made of

Answer 19

a very long, condensed DNA molecules, which is made up of a series of genes

Question 20

how are ends of the chromatids in the chromosome

Answer 20

sealed with protective structures called telomeres

Question 21

what DNA is mitochondrial and chloroplast DNA most similar to

Answer 21

prokaryotic

Question 22

what is mitochondria and chloroplast DNA like

Answer 22

short, circular and not associated with proteins

Question 23

Mitochondria + chloroplast DNA

Answer 23

small circular pieces of DNA

Question 24

what organelles contains their own DNA

Answer 24

mitochondria and chloroplast

Question 25

what is a gene

Answer 25

base sequence of DNA that codes for the amino acids sequence of a polypeptide or functional RNA molecule

Question 26

how is mRNA used

Answer 26

base sequences on mRNA molecules are used by ribosomes to form polypeptide chains

Question 27

how is tRNA used

Answer 27

amino acids are carried to the ribosome by tRNA molecules

Question 28

how is rRNA used

Answer 28

rRNA molecules form part of the structure of ribososmes

Question 29

what does shape and behavior of a proteins molecule depend on

Answer 29

the exact sequence of amino acids (primary structure of the protein)

Question 30

what do genes in DNA molecules control

Answer 30

protein structure as they determine they exact sequence of amino acids joined together when proteins are synthesied in the cell

Question 31

what is DNA essential for

Answer 31

cell survival

Question 32

what does every chromosome consist of

Answer 32

a long DNA molecules and its associated protein

Question 33

what does every chromosome consist of

Answer 33

a long DNA molecule that codes for several different proteins

Question 34

what is a locus

Answer 34

position of a gene on a chromosome

Question 35

what can different alleles of a gene have

Answer 35

slightly different nucleotide sequence but still occupy the same locus on the chromosome

Question 36

gene

Answer 36

base sequence of DNA that codes for the amino acid sequence of polypeptide or functioning DNA

Question 37

3 features of prokaryotic DNA

Answer 37

short, circular and not associated with proteins

Question 38

3 features of eukaryotic DNA

Answer 38

very long, linear and associated with histone proteins

Question 39

what is the DNA nucleotide base code found within the gene

Answer 39

a triplet code

Question 40

how many bases code for 1 amino acid

Answer 40

3

Question 41

triplets of bases known as

Answer 41

codons

Question 42

how many amino acids are there

Answer 42

20

Question 43

what are start and stop signals

Answer 43

triplets of bases which tell the cell where the individual genes starts and stop

Question 44

what do start and stop signals ensure

Answer 44

the cell reads the DNA correctly and can produce the correct sequences of amino acids that require it to function properly

Question 45

how many triplets are possible

Answer 45

64

Question 46

what is degenerate genetic code

Answer 46

multiple codons code for the same amino acid

Question 47

what can degenerate code limit

Answer 47

effect of mutations

Question 48

what is universal genetic code

Answer 48

all organisms use the same code (few exceptions)

Question 49

what does universal code mean

Answer 49

same codons code for same amino acids in all living things so genetic information is transferable between species)

Question 50

3 features of genetic code

Answer 50

non-overlapping, degenerate and universal

Question 51

what does genetic code being non-overlapping mean

Answer 51

each base triplet is read in sequence, separate from specific amino acid before and after it. base triplets don't share their bases

Question 52

which type of cell is non-coding DNA found in

Answer 52

eukaryotic

Question 53

what is non-coding DNA

Answer 53

does not code for any amino acids

Question 54

where can non-coding DNA be found

Answer 54

between genes and within genes

Question 55

how is non-coding DNA found between genes

Answer 55

as non-coding multiple repeats which means they contain the same base sequences repeated multiple times

Question 56

what is the non-coding DNA within genes called

Answer 56

introns

Question 57

how are exons separated

Answer 57

one or more introns

Question 58

what are coding sections of DNA called

Answer 58

exons

Question 59

what is transcribed in transcription

Answer 59

they whole gene (introns and exons) to produce pre-mRNA molecules

Question 60

what is produced in transcription

Answer 60

pre-mRNA molecules

Question 61

what happens before pre-mRNA leaves the nucleus

Answer 61

splicing

Question 62

what is splicing

Answer 62

removing the introns (non-coding sections) and joining together the exons (coding sections)