Subtopic (b) Inheritance SQA questions Inheritance WYSK Certain characteristics are determined by g_______ i_________ received from both p_______ e.g. fur c______, blood g______, stem l_______ and shape of l______ or seeds Each inherited characteristic can appear in a number of forms called p__________. Phenotype is the a__________ of an individual An organism which is t________ b________ e.g. TT or gg produces only o___ type of gamete e.g. _ or _ The F1 offspring of a true breeding cross have u_______ phenotype all the same enetic nformationarents olourroupength eaves henotypes ppearance ruereeding neTg niform A d_________ gene or phenotype always shows A r__________ gene or phenotype can be hidden A m__________ cross is between two true breeding parents which have d_______ phenotypes of the s_______ characteristic E.g. Black (BB) x brown (bb) The symbol for parental generation is __ The symbol for first offspring is __ The symbol for second offspring is __ The expected ratio in F2 is _____ ( : ) Expected ratios dont always happen because f____________ is a r_________ process ominant ecessive onohybrid ifferent ame P F1 F2 3 : 1 ertilisationrandom A parent contributes o___of the two forms of a gene to their o________ A g________ is a sex cell which carries o___ of the two forms of a gene Gametes contain a s________ set of chromosomes Body cells contain a d________ set of chromosomes t___ matching sets The r_________ in the number of chromosomes occurs at g_______ formation At fertilisation chromosome numbers d________ when the m_____ nucleus and the female n_______ fuse together ne ffspring ametene ingle ouble eduction amete ouble aleucleus wo A g____ is part of a chromosome. T___ forms of a gene control each inherited characteristic The genotype is all the g______ an organism contains. Its genetic m____ - up. A______ is the name given to the two forms of a gene The __ and ___ chromosomes determine sex ___ is male and ___ is female The male gamete (s______) may contain an __ or a __ chromosome The female gamete (e___) always contains an ___ chromosome ene wo enes ake llele XY XYXX permX Y gg X Llama and camel successfully interbreed to produce baby Scientists believe he will be infertile XY XX XY XX G tongue rollingsexblood groupsear lobes Presence of operation scars G gametes doubled G horns F1 G gold bodyblack body bb BB Bb bb BB or Bb G 4 : 1 84 black body : 21 gold body Divide by 21: 84 21 = 4 : 1 G discontinuous gametes G tasternon taster G Use the letters T for tasting and t for non tasting to show the forms of gene present in the sex cells of Rab and Audrey t t G gametes XY XX Downs syndrome G XXX Y femalemale F1 G genotype gamete variation G Two/double one/single gametes fertilisation G XXX Y XY XX female G discontinuous Arranged in distinct / clear cut groups C 195 yellow seeds + 65 purple seeds = 260 seeds % yellow : 195 260 = 0.75 X 100 = 75% 75% alleles radiation C GG Gg of 72 = 18 black of 72 = 54 grey C Fertilisation is a random process alleles C TTtt Tt 31 C 41 Fertilisation is a random process C alleles bbBb Fertilisation is a random process C bb Same coat colour discontinuous C all none some RRrr Rr 1RR : 2Rr : 1rr C 496 Fertilisation is a random process Rr rr ratio is 3 red : 1 white 1488 3 = 496 white C alleles Can be arranged into distinct (clear cut) groups C