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Subtopic (b) Inheritance. SQA questions. Inheritance WYSK. enetic. nformation. arents. 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
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Subtopic (b) Inheritance SQA questions
Inheritance WYSK enetic nformation arents • Certain characteristics are determined by g_______ i_________ received from both p_______ e.g. furc______ , blood g______, stem l_______ and shape of l______ or seeds • Each inheritedcharacteristic 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 olour roup ength eaves henotypes ppearance rue reeding ne T g niform
ominant ecessive onohybrid • 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 _____ ( ¾ : ¼ ) • Expected ratios don’t always happen because f____________ is a r_________ process ifferent ame P F1 F2 3 : 1 ertilisation random
ne ffspring amete ne • 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 ingle ouble wo eduction amete ouble ale ucleus
wo ene enes • A g____ is part of a chromosome.T___ formsof a gene control each inheritedcharacteristic • The genotypeis 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 ake llele X Y XY XX perm X Y X gg
G Llama and camel successfully interbreed to produce baby Scientists believe he will be infertile XY XX XX XY
G tongue rolling sex blood groups ear lobes Presence of operation scars
G √ gametes √ doubled √
G horns F1
G BB bb Bb BB or Bb bb gold body black body black body
G 4 : 1 84 black body : 21 gold body Divide by 21: 84÷ 21 21 ÷ 21 = 4 : 1
G √ discontinuous gametes
G taster non taster √
G Use the letters Tfor 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 √ X Y X X Down’s syndrome
G X X X Y female male F1
G genotype gamete variation
G Two/double Two/double one/single one/single Two/double gametes fertilisation
G X X X Y XX XY female female
C 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 ¼ of 72 = 18 black ¾ of 72 = 54 grey 54 18
C Fertilisation is a random process alleles
C TT tt Tt 3 1
C 4 1 Fertilisation is a random process
C alleles bb Bb Fertilisation is a random process
C bb Same coat colour discontinuous
C RR rr Rr Rr 1RR : 2Rr : 1rr all none some
C ratio is 3 red : 1 white 1488 ÷ 3 = 496 white 496 Fertilisation is a random process Rr rr
C alleles Can be arranged into distinct (clear cut) groups