LESSON SUMMARY
- Allele
- Amino acids
- Codon
- DNA
- Gamete
- Genome
- Karyotype
- Phenotype
- Punnett square
- RNA
- Sex chromosome
- Tasks
VOCABULARY
ALLELE One of the possible alternative forms of a gene, often distinguished from other alleles by phenotypic effects.
AMINO ACIDS Aminocarboxylic acids comprising the subunits covalently linked to form proteins.
CHROMATIN The complex of DNA, RNA, histones, and nonhistone proteins that make up uncoiled chromosomes, characteristic of the eukaryotic interphase nucleus.
CODON A triplet of messenger RNA (mRNA) nucleotides that specifies a particular amino acid or a start or stop signal in the genetic code. Sixty-one codons specify the amino acids used in proteins, and three codons, called stop codons (UAG, UAA, UGA), signal termination of growth of the polypeptide chain. One codon (AUG) act as a start codon in addiction to specifying an amino acid.
DNA is a molecule composed of two polynucleotide chains that coil around each other to form a double helix carrying genetic instructions for the development, functioning, growth and reproduction of all known organisms and many viruses.
GAMETE is a haploid cell that fuses with another haploid cell during fertilization in organisms that sexually reproduce.
GENOME is the totality of genetic material carried by an organism.
EXON The DNA segments of a gene that contain the sequences that, through transcription and translation, are eventually represented in the final polypeptide product.
HEMOPHILIA An X-linked trait in humans that is associated with defective blood-clotting mechanisms.
KARYOTYPE The chromosome complement of a cell of an individual. An arrangement of metaphase chromosomes in a sequence according to length and centromere position.
MULTIPLE ALLELES In a population of organisms, the presence of three or more alleles of the same gene.
NUCLEOID The DNA-containing region within the cytoplasm in prokaryotic cells.
PHENOTYPE The overt appearance of a genetically controlled trait.
PALINDROME In genetics, a sequence of DNA base pairs that reads the same backwards or forward. Because strands run antiparallel to one another in DNA, the base sequences on the two strands read the same backwards and forward when read from the 5 end.
PUNNETT SQUARE is a square diagram that is used to predict the genotypes of a particular cross or breeding experiment.
REPLICATION The process whereby DNA is duplicated.
RNA is a polymeric molecule essential in various biological roles in coding, decoding, regulation and expression of genes.
SEX CHROMOSOME A chromosome, such as the X or Y in humans, which is involved in sex determination.
TRANSCRIPTION Transfer of genetic information from DNA by the synthesis of a complementary RNA molecule using one strand of the DNA as a template.
ZYGOTE The diploid cell produced by the fusion of haploid gametic nuclei.
TASKS
ANSWERS
Task 1.1: 1. d 2. a 3. e 4. c 5. b
Task 1.2: 1. b 2. d 3. e 4. a 5. c
Task 1.3: 1. b 2. e 3. a 4. d 5. c