Inheritance CAQ

🤰 Inheritance Created Tags Define sex linked inheritance Alleles are located on X chromosome/ sex chromosome Males have only one X chromosome from the mother while females have two X chromosomes one from each parent Explain how different characteristics can be inherited independently in dihybrid inheritance 9331 phenotypic ratio Indicates that the alleles of each character are found on different chromosomes and inherited independently of one another The alleles of different genes assort independently off each other because alignment of each homologous pair is independent of other homologous pairs Explain why heterozygotes have the same phenotype as dominant homozygotes Dominant allele codes for function enzyme or functional copy of gene involved in synthesis of protein Recessive allele codes for non-functional enzyme/copy of gene Jul y 15 , 2025 1243 AM Inher it ance 1

In a heterozygote, dominant allele mask the presence of recessive allele and presence of 1 dominant allele causes it to be expressed producing a functional enzyme Explain why it would be useful to carry out a chi-squared test To determine if the difference between observed numbers and expected ratio (specify the ratio) was significant or due to chance If the calculated X^2 value is larger than critical value at probability of 0.05 the. There is at least 95% confidence that the observed results are significantly different from the expected results Why is there a greater number than expected of parental phenotypes ( offspring with same phenotypes of parents) The 2 genes coding for specific protein are linked on same chromosome Dominant alleles are linked on the same chromosome Recessive alleles are linked on same chromosome Number of recombinations smaller because crossing over of alleles or recombination is a chance event and frequency of recombination is dependent on distance between the two genes How are recombinants produced in linked chromosomes During prophase I of meiosis I, crossing over between non-sister chromatids occur in the homologous chromosomes At the chiasmata, portion of chromatid containing allele A/a breaks and rejoins to portion containing allele B/b Resulting in new linkage group where Allele A/a and allele B/b are found on the same chromosome Gamete that contained chromosome that contain the new linked chromosome fuses with another gamete that contain to another recombinant chromosome to form the recombinant cell Inher it ance 2

Explain the significance of chi squared value and state and explain the conclusion State the type of inheritance from ratio 9331 follows a normal Mendelian mono hybrid inheritance Check number of degrees of freedom=n-1 where n is number of phenotypes Check the probability where the chi-squared value lies Eg. Chi squared value is 0.47 with number degree of freedom=3, at a level of significance if chi squared value X^2 is less than critical value at a level of significance we do not reject the null hypothesis Opposite of z test) The difference between observed and expected phenotypic ratios is not significant difference and is due to chance Inheritance of these genes follows Mendels laws of independent assortment, random segregation and dominance Explain how pure-breeding offspringʼs can be selected and obtained from previous cross Perform a cross test between off spring from previous cross with a homozygous recessive offspring If all offspring have the same phenotype then the original parent is a pure bred If offspring produced a ratio of 11, original parent is not pure bred Explaining epistasis according to context Figure out the pathway to produce the phenotype Does the genotype result in production of inhibitor to prevent conversion of letʼs say from colour to colour or does it produce a functional protein that converts colour to colour Inher it ance 3

The genotype that produces inhibitors usually is epistatic as it masks the phenotypic expression of another genotype Inher it ance 4