Module 5: Heredity - Practice Paper
HSC Biology Practice Paper
Module 5: Heredity
Reading time: 5 minutes
Working time: 3 hours
Write using black penDraw diagrams using pencil
Calculators approved by NESA may be used
Total marks: 100
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Section I
Question 1
Yeast can reproduce by budding. Which statement best describes the daughter cell produced by this process?
A. It is genetically identical to the parent cell.
B. It contains half the number of chromosomes of the parent cell.
C. It is genetically different because fertilisation has occurred.
D. It contains DNA from two different parent cells.
Question 2
A. It prevents all genetic variation in offspring.
B. It reduces the risk of gametes drying out.
C. It requires large numbers of gametes to be released into water.
D. It allows fertilisation to occur without contact between male and female gametes.
Question 3
A. anther.
B. ovary.
C. ovule.
D. stigma.
Question 4
Some fungi reproduce asexually by producing spores. How does this process help ensure continuity of the species?
A. Spores combine with sperm cells to form zygotes.
B. Spores allow fungi to reproduce only when two parents are present.
C. Spores can be dispersed and grow into new organisms in favourable conditions.
D. Spores prevent the production of genetically identical offspring.
Question 5
A bacterial population contains 50 cells. The population doubles every 20 minutes. How many bacterial cells will be present after 60 minutes?
A. 100
B. 150
C. 300
D. 400
Question 6
A mammal has 2n = 38 chromosomes in its body cells. How many chromosomes would normally be present in one sperm cell?
A. 19
B. 38
C. 57
D. 76
Question 7
A section of DNA has the following sequence.
A T G C C A T T A
A. A T G C C A T T A
B. U A C G G U A A U
C. T A C G G T A A T
D. C G T A A C G G C
Question 8
A. Sugar: Ribose; base found in DNA: Uracil
B. Sugar: Deoxyribose; base found in DNA: Thymine
C. Sugar: Ribose; base found in DNA: Thymine
D. Sugar: Deoxyribose; base found in DNA: Uracil
Question 9
A. Prokaryotic DNA: linear and found in the nucleus; eukaryotic DNA: circular and found in the cytoplasm
B. Prokaryotic DNA: circular and found in the cytoplasm; eukaryotic DNA: linear and found in the nucleus
C. Prokaryotic DNA: circular and found in the nucleus; eukaryotic DNA: linear and found in the cytoplasm
D. Prokaryotic DNA: linear and found in the cytoplasm; eukaryotic DNA: circular and found in the nucleus
Question 10
A. each new DNA molecule contains two newly made strands.
B. each new DNA molecule contains one original strand and one newly made strand.
C. the original DNA molecule remains unchanged and no new DNA is produced.
D. only half of the genes in the DNA molecule are copied.
Question 11
A. A U G C C U
B. T A C G G A
C. A T G C C T
D. U A C G G A
Question 12
A. It carries amino acids to the ribosome.
B. It unzips DNA in the nucleus.
C. It joins nucleotides during DNA replication.
D. It forms the sugar-phosphate backbone of DNA.
Question 13
A. folding of one polypeptide chain.
B. order of amino acids in a polypeptide chain.
C. interaction between several polypeptide chains.
D. bonding between phosphate and sugar molecules.
Question 14
In pea plants, tall stems are dominant to short stems. A heterozygous tall plant is crossed with a short plant. What is the expected phenotypic ratio of the offspring?
A. 1 tall : 1 short
B. 3 tall : 1 short
C. 1 tall : 3 short
D. 100% tall
Question 15
A recessive condition is carried on the X chromosome. A carrier female and an unaffected male have children. What is the chance that a son will inherit the condition?
A. 0%
B. 25%
C. 50%
D. 100%
Question 16
When a red-flowered plant is crossed with a white-flowered plant, all offspring have pink flowers. Which inheritance pattern is shown?
A. Codominance
B. Incomplete dominance
C. Multiple alleles
D. Sex-linked inheritance
Question 17
A person with blood type A has genotype IA i. A person with blood type B has genotype IB i. Which blood types could their children have?
A. A only
B. A and B only
C. A, B and AB only
D. A, B, AB and O
Question 18
A. produces genetically identical gametes.
B. exchanges sections of DNA between homologous chromosomes.
C. prevents independent assortment from occurring.
D. doubles the chromosome number in gametes.
Question 19
A population of 100 diploid organisms has the following genotypes for a gene:
Genotype | Number of individuals |
BB | 36 |
Bb | 48 |
bb | 16 |
A. 0.36
B. 0.48
C. 0.60
D. 0.84
Question 20
A. compares inherited DNA sequences or markers.
B. changes the DNA sequence of related individuals.
C. prevents mutations from occurring in gametes.
D. produces genetically identical organisms.
Section II
Question 21
(a) (1 mark) Identify the three components of a DNA nucleotide.
(b) (2 marks) Compare prokaryotic and eukaryotic DNA with reference to location and structure.
Question 22
(a) (2 marks) Outline how a named organism reproduces asexually.
(b) (3 marks) Compare sexual reproduction and asexual reproduction in terms of genetic variation and continuity of species.
Question 23
The table shows changes in the relative concentration of three hormones during human pregnancy.
Hormone | Time of highest relative concentration |
hCG | Weeks 8-10 |
Progesterone | Late pregnancy |
Oestrogen | Late pregnancy |
(4 marks) For TWO hormones in the table, identify their role in pregnancy and state when their concentration is highest.
Question 24
During DNA replication, each strand of the original DNA molecule acts as a template.
A section of an original DNA strand is shown: A T C G G T A
(a) (2 marks) Write the complementary DNA strand that would be produced.
(b) (3 marks) Explain why accurate DNA replication is important for the continuity of a species.
Question 25
An organism has two pairs of homologous chromosomes. The organism is heterozygous for two genes, AaBb. The A/a alleles are on one chromosome pair and the B/b alleles are on a different chromosome pair.
(a) (3 marks) Describe TWO processes during meiosis that increase genetic variation in gametes.
(b) (4 marks) Construct the possible gametes produced by this organism and explain how fertilisation further increases genetic variation in offspring.
Question 26
In snapdragons, flower colour is controlled by a gene with two alleles.
Genotype | Phenotype |
RR | Red flowers |
WW | White flowers |
RW | Pink flowers |
Two pink snapdragons are crossed.
(a) (3 marks) Use a Punnett square to predict the phenotypic ratio of the offspring.
(b) (2 marks) Identify the inheritance pattern shown and justify your answer.
Question 27
A genetic condition is caused by a recessive allele, r. The normal allele is R. Two unaffected parents have two children. One child is affected by the condition and one child is unaffected.
(a) (3 marks) Determine the genotypes of the two parents and the affected child. Justify your answer.
(b) (3 marks) Use a Punnett square to determine the probability that another child of the same parents will be affected by the condition.
Question 28
The DNA template strand for part of a gene is shown:
T A C T T T G G A C T C A T T
The following codon information may be used.
mRNA codon | Amino acid |
AUG | Methionine |
AAA | Lysine |
CCU | Proline |
GAG | Glutamic acid |
UAA | Stop |
(a) (2 marks) Transcribe the DNA template strand into mRNA.
(b) (3 marks) Use the codon table to determine the amino acid sequence produced.
(c) (2 marks) Explain the role of ribosomes and tRNA in translation.
Question 29
The table shows the percentage similarity for two traits in different sibling groups raised in a shared family environment.
Sibling group | Trait X similarity (%) | Trait Y similarity (%) |
Identical twins | 90 | 60 |
Biological siblings | 45 | 58 |
Adoptive siblings | 5 | 55 |
(4 marks) Analyse the data to determine the relative influence of genes and environment on Trait X and Trait Y.
Question 30
DNA profiling was carried out using three STR loci. A child inherited one allele at each locus from the mother and one allele at each locus from the biological father.
Individual | STR 1 | STR 2 | STR 3 |
Mother | 10, 14 | 7, 9 | 20, 22 |
Child | 10, 18 | 7, 11 | 18, 22 |
Male A | 18, 19 | 11, 13 | 18, 21 |
Male B | 18, 18 | 8, 11 | 20, 20 |
Male C | 14, 15 | 10, 10 | 18, 23 |
(a) (3 marks) Identify the most likely biological father. Justify your answer using the data.
(b) (3 marks) Explain how DNA profiling can be used to study inheritance patterns in populations.
Question 31
A population study of 80 diploid animals examined a gene with two alleles, H and h. The H allele was counted 96 times in the population.
(a) (2 marks) Calculate the frequency of the H allele and the h allele.
(b) (3 marks) Explain how allele frequency data can be useful when studying inheritance patterns in a population.
Question 32
A fruit grower wants to produce apple plants with high fruit yield. The grower is considering artificial pollination and cloning.
(a) (3 marks) Outline how artificial pollination can be used to produce offspring with desired characteristics.
(b) (4 marks) Compare artificial pollination and cloning as methods for maintaining desired characteristics in agriculture.
Question 33
(4 marks) Describe TWO asexual reproductive methods used by organisms and explain how each method contributes to the continuity of a species.
Question 34
A student investigated whether plant species affects pollen tube growth.
The student used pollen from Species A on growth medium containing 10% sucrose at 25 degrees C. The student used pollen from Species B on growth medium containing 20% sucrose at 30 degrees C. One slide was prepared for each species. After 20 minutes, pollen tube length was measured.
(4 marks) Evaluate the validity and reliability of this investigation.
Question 35
(8 marks) Analyse how reproduction and heredity ensure continuity of species while also producing genetic variation.
In your answer, refer to:
asexual reproduction
sexual reproduction
DNA replication and cell division
inheritance patterns or allele combinations
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