Topic 3: Genetics Flashcards
What is an allele?
A version of a gene.
What are amino acids?
Small molecules from which proteins are assembled.
What is an anticodon?
A triplet sequence of bases on a tRNA molecule that is complementary to a specific codon in mRNA.
What is asexual reproduction?
A form of reproduction involving a single parent that creates genetically identical offspring.
What is a base triplet?
A sequence of three bases in a gene that code for a particular amino acid. Also known as a codon.
What is a blood group?
Classification of blood type as A, B or O based on surface antigens on red blood cells and the presence of certain antibodies in the plasma.
What is a chromosome?
A long, coiled molecule of DNA that carries genetic information in the form of genes.
What is coding DNA?
A sequence of DNA that codes for the production of a protein.
What is codominance?
When both alleles for a gene in a heterozygous organism equally contribute to the phenotype.
What is a codon?
See ‘Base triplet’.
What is complementary base pairing?
Describes how weak hydrogen bonds form between complementary base pairs. A pairs with T and C pairs with G.
What is detergent used for in DNA extraction?
A chemical that is used to disrupt cell membranes in the extraction of DNA.
What is a diploid cell?
A cell that contains two copies of each chromosome (i.e. a full set of chromosomes).
What is DNA?
A double-stranded polymer, wound to form a double helix, that carries the genetic code.
What is a phenotype?
An organism’s observable characteristics due to interactions of the genotype and the environment.
What is a protein?
A large molecule that is synthesised from amino acids.
What is protein synthesis?
The formation of a protein from a gene.
What is a Punnett square?
A grid used to predict the potential outcomes of a genetic cross.
What does recessive mean?
Describes an allele that is only expressed in the absence of a dominant allele. Represented by a small letter.
What is a reproductive cycle?
The time required to produce independent offspring.
What are ribosomes?
Sub-cellular structures that are the site of protein synthesis.
What is RNA polymerase?
An enzyme involved in transcription that binds to a region of non-coding DNA, unzips the DNA strands and joins free RNA nucleotides to complementary bases on the coding DNA strand.
What are sex chromosomes?
A pair of chromosomes responsible for the determination of gender. XY in males, XX in females.
What is a sex-linked characteristic?
A characteristic that is coded for by an allele found on a sex chromosome.
What is a sex-linked genetic disorder?
A disorder caused by a faulty allele located on a sex chromosome.
What is sexual reproduction?
A form of reproduction that creates genetic variation, involving the fusion of male and female gametes.
What is transcription?
The first stage of protein synthesis in which mRNA is formed from a DNA template.
What is translation?
The second stage of protein synthesis that takes place in the ribosomes. Amino acids are joined in a specific order dictated by mRNA to form a protein.
What is tRNA?
An RNA molecule that carries specific amino acids to the ribosomes during protein synthesis.
What is variation?
The differences between individuals due to genes, the environment or a combination of both.
What is a zygote?
A diploid cell formed by the fusion of the nucleus of a male gamete with the nucleus of a female gamete.
