Flashcards in Topic 3 - Genetics Deck (68):
Which structures are found inside the nucleus?
Which substance forms a long strand in each chromosome?
How do body cells make copies of themselves?
cell division, mitosis
How many chromosomes are there in a human body cell nucleus?
What happens in fertilisation?
two gametes fuse
What is the name of the cell formed in fertilisation?
zygote, fertilised egg cell
Which term means producing more of the same kind of organism?
What is the name of the human male gamete?
The DNA strand in a chromosome contains sections that carry instructions for characteristics. What are these sections called?
What molecule forms the genome of an organism?
Where are genes found?
[in sections of DNA] on chromosomes
What does a gene carry the instructions for?
making a protein
A protein is made by linking together smaller molecules. What are these smaller molecules called?
What is any molecule made of repeating units called?
A human cell contains 46 strands of DNA. Is it diploid or haploid?
Are the cells produced by meiosis haploid or diploid?
Are the cells produced by mitosis haploid or diploid?
What shape is DNA?
a double helix
What is a chromosome made out of?
DNA and proteins [to package the DNA]
What shape is a DNA molecule?
What part of a DNA strand contains the instructions for a protein?
What are the letters of the bases that form the DNA code?
A,C,T and G
How do these bases pair up in DNA?
A with T, C with G
Apart from bases, what other parts are needed in a DNA molecule?
phosphate group, sugar
What is one phosphate group, one sugar and one base called?
Why is DNA a polymer?
It is made of many nucleotides joined in a chain.
Give an example of a protein.
any example. E.g. an enzyme
How is the active site of an enzyme formed?
by folding of protein/polypeptide/amino acid chains
Why are proteins polymers?
They are made of many amino acids joined in a chain.
Triple only- What molecule is produced in transcription?
mRNA or messenger RNA
Triple only- What base does mRNA contain that DNA does not?
Triple only-What is the name of the enzyme that allows transcription to occur?
Triple only-The mRNA nucleotides fit together with the nucleotides on the DNA template strand. What word describes bases that fit together?
Triple only- Where does transcription occur in a cell?
Triple only-Where does translation occur in a cell?
Triple only-What has to bind to an mRNA molecule for translation to occur?
Triple only-What molecule carries amino acids to the mRNA in the ribosome?
Triple only- What has to happen to the polypeptide for an enzyme in order for it to become a functional enzyme?
It has to fold
How many bases does a codon contain?
Triple only-What does each codon contain the code for?
the addition of a particular amino acid to the polypeptide chain
Triple only-What is the name of the process in which the genetic code is used to make a polypeptide?
A change in the bases of a gene creates a genetic variant. What is this sort of change called?
Triple only-What does translation produce?
Triple only- Why might a mutation in a codon not cause a change in the polypeptide produced?
It does not affect the amino acid that is coded for.
Triple only- Why can a difference of a single amino acid change how a protein functions?
It can interfere with the way the polypeptide chain(s) fold(s).
Triple only- What has to bind to an mRNA molecule for translation to occur?
Triple only- Why might a mutation in the non-coding region before a gene cause an increase in the production of a certain protein?
The mutation causes RNA polymerase to bind better.
What is an organism’s phenotype?
its observed characteristics
What are different versions of the same gene called?
What sort of variation do alleles cause in organisms?
When we consider one gene, what word is used to say that both alleles are the same?
If a dominant allele has the letter A, how would you show that an organism is heterozygous?
What word describes the characteristics caused by the alleles of a gene?
What word describes the alleles of a gene found in an organism?
What word describes an allele that only has an effect if an organism has two copies?
A genotype is written QQ. What does this tell you?
It is homozygous for the dominant allele.
What is a probability?
the chance of an event occurring
If the occurrence of an event has a probability of 1, what does this mean?
It is certain to occur.
Triple only- What is monohybrid inheritance?
inheritance of alleles of one gene
Triple only- In monohybrid inheritance, what is the theoretical probability of parents who are both heterozygous for a gene producing an offspring that is also heterozygous for the gene?
probability 50 per cent or half
Triple only- In monohybrid inheritance, what is the theoretical ratio of dominant to recessive phenotypes produced by parents who are both heterozygous for the characteristic?
Triple only- What letters are used to describe the different human blood groups?
A, B, O
How can we show the possible inheritance of alleles by offspring from their parents?
genetic diagram, Punnett square
Which type of diagram is used to show the inheritance of a characteristic through different generations in a family?
If the genotype for one gene of a rabbit is Bb, where B is the allele for brown coat and b the allele for black coat, what is the rabbit’s phenotype?
What are the possible allele combinations of offspring from heterozygous parents who are both Aa for a gene?
AA, Aa and aa
A human egg cell that contains an X sex chromosome is fertilised by a sperm cell containing a Y sex chromosome. What will be the sex of the baby that develops?