B1

• Eukaryotic cells - store genetic material (DNA) inside a nucleus. e.g animal and plant cells
• Prokaryotic cells - have no nucleus, instead there is a chromosome and they might have small rings of DNA called plasmids. e.g bacteria
• DNA - long molecule carrying the genetic code
• Genome - entire genetic material of an organism
• nucleus - where genetic material is stored in eukaryotic cells
• chromosome - long strands of DNA is found in nucleus
• gene - section of DNA that codes for proteins for our physical characteristics
• DNA structure - molecule that makes up chromosomes, has double helix structure of smaller molecules called nucleotides. Made from phosphate and sugar backbone with a base. There are 4 bases A - T and C - G
• Proteins are large molecules made from amino acids joined together by chemical bonds
• How proteins are made - DNA double helix unzips exposing gene that is needed. MRNA forms a copy of the gene and base T is replaced with U. MRNA is a single strand and leaves nucleus entering the cytoplasm. A ribosome reads the MRNA 3 bases at a time (triplet code). This codes for one amino acid. Amino acids then join in a long chain to form a protein
• Genetic Engineering - when a genome is modified to change an organism's characteristics
• Genetically modified crops can impact human heath and affect other organisms within an ecosystem
• Genetically modified crops - crops that have been genetically modified to produce a trait that is beneficial to humans
• Dominant allele - always expressed when inherited in a genotype.
• Recessive allele - only expressed when there is 2 copies in the genotype
• Homozygous - Having two identical alleles of same gene, e.g. BB
• Heterozygous - Having two different alleles for same gene e.g Bb
• Inheritance - transfer of genetic material from parents to offspring
• phenotype - physical characteristics of an organism determined by genes
• Variant - caused by mutations in DNA (change in sequence of bases)