2.1.3 DNA codes for a particular protein but cannot leave nucleus One strand of DNA is used as a template to form mRNA (3) 2.1.4 According to the codons on mRNA tRNA molecules with matching anticodons bring the required amino acids to the ribosome This is called translation The amino acids become attached by peptide bonds to form the required protein (any 4) (4) Methionine, Glycine, Arginine (in the correct order) (3) 2.1.5 (14) 2.2 2.2.1 H. erectus (1) 2.2.2 A. afarensis (1) 2.2.3 (a) 3 mya 2,4 mya = 0,6 my – OR 3 mya 2,3 mya = 0,7 my (3) – (b) Fossils (1) 2.2.4 (a) H. neanderthalensis (1) (b) H. neanderthalensis and H. sapiens share a common (2) ancestor OR Both evolved from H heidelbergensis (2) (9) 2.3 2.3.1 The homologous chromosome pair does not separate/non-disjunction during anaphase 1 (3) 2.3.2 1 (1) 2.3.3 Down syndrome (1) 2.3.4 During crossing over in Prophase 1 segments of chromatids of homologous chromosomes are exchanged leading to each gamete having a mix of genetic material from both parents (any 4)
2.1.3 2.1.4 2.1.5 DNA codes for a particular protein but cannot leave nucleus One strand of DNA is used as a template to form mRNA According to the codons on mRNA tRNA molecules with matching anticodons bring the required amino acids to the ribosome This is called translation The amino acids become attached by peptide bonds to form the required protein (any 4) Methionine, Glycine, Arginine (in the correct order) (3) (4) (3) (14) 2.2 2.2.1 2.2.2 H. erectus A. afarensis (1) (1) 2.2.3 2.2.4 (a) 3 mya – 2,4 mya = 0,6 my OR 3 mya – 2,3 mya = 0,7 my (b) Fossils (a) H. neanderthalensis (b) H. neanderthalensis and H. sapiens share a common ancestor OR Both evolved from H heidelbergensis (3) (1) (1) (2) (2) (9) 2.3 2.3.1 The homologous chromosome pair does not separate/non-disjunction during anaphase 1 (3) 2.3.2 1 (1) 2.3.3 Down syndrome (1) 2.3.4 During crossing over in Prophase 1 segments of chromatids of homologous chromosomes are exchanged leading to each gamete having a mix of genetic material from both parents (any 4)