Biology Unit 2 AOS 2 Practice Test PDF

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Practice exam for area of study 2. this will helo in preperation for exams and enable you to do better. this is a great way to prepare for your exams. use this document to better yourself for unit 2...

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Unit 2 AOS 2 Practice Test Question 1 The purpose of the Human Genome Project was to: A compare human DNA with ape DNA B identify all of the human genetic diseases C identify and sequence the entire human genome D identify mutations in the donor of the DNA sample Question 2 Which of the following genotypes shows alleles for a heterozygous trait? A AA B Bb C CD D Cd Question 3 ‘Carried on the X-chromosome’ and ‘occurs more commonly in males than in females’ suggests: A monohybrid cross B dihybrid cross C autosomal-linked inheritance D sex-linked inheritance Question 4 Identify what each pedigree symbol means

Question 5 Describe the patterns expected in a pedigree for each type of inheritance A Autosomal dominant B Autosomal recessive C X-linked dominant D X-linked recessive E Y linked

ANSWERS Question 6 Complete the following crosses and for each state: i The possible genotypes ii The possible phenotypes iii The probabilities of each A Eye colour, B= Brown and b = blue, Bb x Bb

i ii iii B

The possible genotypes: The possible phenotype: The probabilities of each: Blood types, IAi x IBi

i ii iii C

The possible genotypes: The possible phenotype: The probabilities of each: Hemophilia B, T= normal blood clotting, t= Hemophilia B, XTXt x XtY

i

The possible genotypes:

ANSWERS ii iii

The possible phenotype: The probabilities of each:

Question 7 Analyse the following karyotypes and identify if they are normal or what condition the individual has A

Analysis: B

Analysis: C

Analysis:

ANSWERS

D

Analysis: E

Analysis: F

Analysis: Question 8 What 3 things can cause variation in offspring Question 9 List some possible ethical concerns associated with genetic testing

ANSWERS

Question 10 Define linked genes Question 11 Define polygenic traits and give 3 examples Question 12 Complete the following dihybrid crosses and identify all possible genotypes, phenotypes and the probabilities of each. For both crosses: B = Brown fur, b = white fur, G = green eyes, g = red eyes A BBGG x bbgg

i ii iii B

The possible genotypes: The possible phenotype: The probabilities of each: BbGg x BbGg

i ii

The possible genotypes: The possible phenotype:

ANSWERS iii

The probabilities of each:

Question 13 What is the ratio seen in the phenotypes of the dihybrid crosses in question 12B, and what could be the reason for not getting a ratio like this? Question 14 The snowshoe hare’s fur is brown in summer and white in winter. The change in fur colour is caused by epigenetic factors.

A Outline what is meant by epigenetic factors. B Identify 2 examples of the effect of epigenetics. Question 15 Define gene locus. Question 16 A person has the genotype TtWw, how many different gametes could they produce and show them below. Question 17 If two genes are linked explain how this affects the proportion of each of the different gametes produced. Question 18 List the advantages and disadvantages of genetically testing a foetus. Question 19

From the pedigree determine the following: A B

The probability that III-4 is heterozygous for the condition. The probability that II-1 and II-2 could have had a 3rd child who had the condition

ANSWERS

Question 20 Identify the type of inheritance seen in the following pedigrees A

Analysis: B

Analysis: C

Analysis:

ANSWERS

D

Analysis: E

Analysis: Question 21 The pedigree below shows the transmission of Cystic Fibrosis within a family.

A B

Identify the type of inheritance (autosomal/sex-linked, dominant/recessive) and use the pedigree to justify your answer. Assign allelic symbols for the condition

ANSWERS No Cystic Fibrosis:

Cystic Fibrosis:

C Determine the genotype and phenotype of III-5 and III-6 D Complete the Punnett square between III-5 and III-6

E F

What are the possible genotypes and phenotypes of their offspring and the probabilities of each? What’s the probability their second child won’t have Cystic Fibrosis?

Question 22 Boys can inherit the X-linked allele (Xc) that causes the recessive phenotype red–green colour blindness. A Explain the following terms: i X-linked allele ii recessive phenotype. B Write down the possible genotypes for red–green colour blindness in: i Men ii women. C A boy inherited red–green colour blindness from one of his grandfathers. Which of the boy’s grandfathers (maternal or paternal) was also colour blind? Explain your reasoning D A red–green colour-blind woman and an unaffected man had five children: three boys and two girls. The three boys and the elder girl did not marry. The younger girl married a man with normal colour vision, and they had four children: two boys and two girls. Draw a pedigree chart to illustrate the inheritance of the X-linked condition in this family. Use conventional symbols. Question 23 In the garden pea, Pisum sativum, the phenotype for tall plants (allele represented as T) is dominant over the phenotype for short plants (t). The phenotype for round seeds (R) is dominant over the phenotype for wrinkled seeds (r). The alleles are unlinked. Pure-breeding tall plants with round seeds were crossed with pure-breeding short plants with wrinkled seeds. The F1 plants were then crossed with plants that had the genotype ttrr. The table below shows the results obtained in the F2 generation.

A B

State the genotype and the phenotype of the F1 individuals. Draw up a Punnett square to show the expected ratio of phenotypes in the F2 generation.

ANSWERS Are the results listed in the table exactly as you expected? If not, suggest an explanation for the differences. Question 24 In fruit flies (Drosophila melanogaster), the grey body phenotype (allele G) is dominant to black body (g), and normal wing shape (N) is dominant to vestigial wings (n). The genes for these traits are linked. Male flies heterozygous for both grey body and normal wings were mated with black-bodied and vestigial winged females. Five thousand offspring were examined for body colour and wing type. The following table shows the results obtained. C

Contrast linked and unlinked genes. The genotype for the female parental flies can be represented as ggnn. Suggest a possible genotype designation for the male parentals. C Does the experiment provide evidence for recombination of linked genes? Explain your answer. D Identify which offspring are the result of recombination in this cross. A B...