Flashcards
Year 11 - Topic 3: DNA and Inheritance
Cards in this deck (25)
- 1Describe the structure of DNADNA contain four bases - adenine, thymine, guanine and cytosine. These bases pair up (A-T, C-G) to bases on another strand with hydrogen bonds to form a double helix.
- 2What is a triplet code?Each triplet code identifies a particular amino acid.
- 3What is genetic profiling?Genetic profiling is the analysis of a person's DNA
- 4How is a genetic profile produced?DNA is cut into short pieces using enzymes.
The cut up pieces of DNA are then placed in the wells of a gel and an electric current is passed through (electrophoresis).
The DNA travels up the gel - smaller fragments go further. - 5What can genetic profiling be used for?Samples can be compared for paternity tests, criminal cases and in comparisons between species for classification purposes.
- 6What is a gene?Sections of DNA molecules that determine inherited characteristics
- 7What is an allele?Different forms of a particular gene e.g. eye colour - blue, brown
- 8What is a chromosome?A length of DNA that contains many genes, found in the nucleus and visible during cell division
- 9In genetics, what is meant by the term dominant?An allele that shows the phenotype whenever it is present (shown by a capital letter)
- 10In genetics, what is meant by the term recessive?An allele that is hidden when a dominant allele is present (shown by a lower case letter)
- 11In genetics, what is meant by the term homozygous?Contains two identical alleles for the gene concerned (e.g. BB, bb)
- 12In genetics, what is meant by the term heterozygous?Contains two different alleles for the gene concerned (e.g. Bb)
- 13In genetics, what is meant by the term genotype?The genetic makeup of an individual
- 14In genetics, what is meant by the term phenotype?The description of the way the genotype ‘shows itself’ (e.g. blue eyes, red flowers)
- 15In genetics, what is meant by the term F1/F2?Short for first generation (F1) and second generation (F2)
- 16In genetics, what is meant by the term selfing?A technique by which pollen from a plant is used to fertilise ovules in flowers of the same plant
- 17If a tall plant (TT) is crossed with a short plant (tt), what is the percentage chance of a tall plant being produced?100% chance of plant being tall
- 18If a person with blue eyes (bb) has child with a person with brown eyes (Bb), what is the percentage chance of having a child with brown eyes?50% chance of having a child with brown eyes
- 19Tall allele is dominant, short allele is recessive. If a homozygous recessive plant is crossed with a heterozygous plant, what is the ratio of tall plants to short plants produced?1:1 (2:2)
- 20How many pairs of chromosomes do humans have?23 pairs
- 21On what pair of chromosomes is the sex of the person determined?23rd pair
- 22What are the alleles for male and female?Male = XY
Female = XX - 23What is genetic modification?Genes can be transferred from one organism to another.
- 24What are the advantages of genetic modification?Depends on the organism in question but could include disease resistance and increased yield
- 25What are the disadvantages of genetic modification?Depends on the organism in question but could include effects on health and the environment (e.g. give rise to super weeds)
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- GCSE Biology Flashcards on Year 11 - Topic 3: DNA and Inheritance, created by Mrs Z Rourke on 07/03/2018.
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- Mrs Z Rourke
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