Topic 3 Flashcards
which term is used to describe the expression of traits in an organism?
A) genotype
B) phenotype
C) allele
D) gamete
B) phenotype
figure 17 shows structure of a DNA nucleotide
structure a is a
A) base
B) phosphate
C) sugar
D) polymer
C) sugar
transcription and translation are stages in protein synthesis. which enzyme is involved in the process of transcription?
A) DNA ligase
B) lysozyme
C) RNA polymerase
D) restriction endonuclease
C) RNA polymerase
describe how a mutation in the non coding region of the dna can prevent a gene being transcribed
prevents binding of RNA polymerase to non coding DNA meaning that mRNA cannot be produced
which statement correctly describes a DNA molecule?
A) two strands joined together by strong bonds to form a double helix
B) two complementary bases twisted into a double helix by strong bonds
C) a double helix with strands joined by hydrogen bonds between bases
D) four complementary strands joined together with hydrogen bonds
C) a double helix with strands joined by hydrogen bonds between bases
state the term used to describe a change in the sequence of DNA bases
mutation
scientist obtained a mass of 0.0062 nanograms of DNA form a diploid human cell. calculate the mass of DNA the scientist should obtain from a haploid human cell.
give answer in pictograms
- 0062 / 2 = 0.0031
0. 0031 x 1000 = 3.1
compare the outcomes of mitosis and meiosis
mitosis produces 2 genetically identical cells but meiosis produces 4 genetically different cells. mitosis produces body cells and meiosis produces gametes
state what is meant by the term genome
entire genetic material of an organism
explain one advantage of pea plants using sexual reproduction to produce offspring
increase in genetic variation so they are more likely to survive a disease (survival of the fittest)
genetic analysis shows changes in the sequence of the birds DNA. give the complementary strand sequence for this DNA template
ATGTTACGT
TACAATGCA
explain how a change in the DNA sequence of a gene can result in the production of a different protein
changes the sequence of mRNA produced in transcription. this leads to a different amino acid and this changes the shape and function of the protein
describe the stage of transcription
- double stranded DNA unzipped
- the base sequence of the gene is copied into a complementary template molecule - mRNA
- enzyme RNA polymerase joins mRNA template together
- mRNA passes out of nucleus into cytoplasm
describe the stage of translation
- mRNA molecule attaches to a ribosome
- amino acids brought to ribosome on carrier molecules - tRNA
- ribosome reads the triplets of bases on the mRNA and uses this to join together the correct amino acids in correct order
describe the outcome of protein synthesis
the long protein chain folds up, giving it a unique structure
structure is essential to the protein’s function
