3 (a) Fig. 3.1 is a diagram showing stages during the development of a human embryo and fetus. Fig. 3.1 (i) Put a tick (3) in the box that describes a human embryo. a ball of cells a cell with energy stores and a jelly coating a cell with a flagellum is made of cells that have a cell wall [1] (ii) Table 3.1 shows some of the events (D to J) that occur between fertilisation and birth. The events are not in the correct order. Table 3.1 D a baby is born E complexity of the fetus increases more than size F a zygote is formed G embryo implants into the wall of the uterus H size of the fetus increases more than complexity J the zygote divides by mitosis to produce two cells Put the events into the correct sequence by ordering the letters. One has been done for you. J [3] (b) Complete the sentences using the words and phrases from the list. Each word or phrase may be used once, more than once or not at all. afterbirth amniotic sac amniotic fluid cervix oviduct penis umbilical cord uterus wall vagina Birth begins when the strong muscles of the … start to contract. This causes the … to dilate. The … can break at this stage. The muscles start to push the baby out. The baby moves through the … . The … is tied and cut. Finally the … is delivered. [6] [Total: 10]

3(a)(i) tick in the box next to ‘a ball of cells’ ; 1 R additional ticks 3(a)(ii) ;;; F J G E H D 3 one mark for F at the start and D at the end one mark for G before E one mark for E before H 3(b) uterus wall ; cervix ; amniotic sac ; vagina / cervix ; umbilical cord ; afterbirth ; 6 To earn marks, you must tick only the box next to 'a ball of cells'. For the sequence, you need to correctly order the events as F, J, G, E, H, D, specifically ensuring F is at the start, D at the end, G before E, and E before H. For the fill-in-the-blanks, you must correctly use 'uterus wall', 'cervix', 'amniotic sac', 'vagina' (or 'cervix'), 'umbilical cord', and 'afterbirth' in the correct order.

3 (a) A species of pea plant can produce green or yellow peas. Fig. 3.1 shows a photograph of a green pea and a yellow pea. green pea yellow pea pea A pea B Fig. 3.1 The colour of peas is controlled by a single gene: • The allele for yellow peas is dominant and is represented by the letter G. • The allele for green peas is recessive and is represented by the letter g. (i) Use your knowledge and this information to complete Table 3.1. Table 3.1 genotype of pea A phenotype of pea B phenotype of a pea with a heterozygous genotype [3] (ii) Two pea plants were crossed. Complete the genetic diagram in Fig. 3.2 to show the outcome of the cross. parental gametes g g parental gametes G … … g … … ratio of yellow offspring : green offspring … : … [2] Fig. 3.2 (b) Cystic fibrosis is a disease caused by a recessive allele in humans. Fig. 3.3 is a pedigree diagram showing the inheritance of cystic fibrosis in a family. R S T U V W Key: female without cystic fibrosis female with cystic fibrosis male without cystic fibrosis male with cystic fibrosis Fig. 3.3 (i) State the number of people that have cystic fibrosis. … [1] (ii) Identify the letter of a person that must have a heterozygous genotype. … [1] (iii) Person U has a homozygous dominant genotype. Circle the probability of person U having a child with cystic fibrosis. 0% 25% 50% 75% 100% [1] [Total: 8]

3(a)(i) gg ; yellow ; yellow ; 3 3(a)(ii) top row both offspring Gg, bottom row both offspring gg ; 1:1 ; 2 3(b)(i) 2 ; 1 3(b)(ii) R / S ; 1 3(b)(iii) 0% circled ; 1

4 (a) (i) Define the term genetic engineering. … … … … … [2] (ii) State one example of genetic engineering. … … … [1] (b) Fig. 4.1 is a diagram of a fruit fly with normal wings and a fruit fly with vestigial wings. normal wings vestigial wings Fig. 4.1 A gene determines whether fruit flies have normal wings or vestigial wings. There are two alleles for this gene: • A is dominant and represents the allele for normal wings • a is recessive and represents the allele for vestigial wings. (i) A homozygous dominant fruit fly was crossed with a heterozygous fruit fly. Complete the genetic diagram to predict the probability of the offspring having vestigial wings. parental phenotypes normal wings × normal wings parental genotypes ..…………… × ..…………… gametes ..…….. , ..…….. × ..….…. , ..…….. offspring genotypes ..………….. ..………….. ..………….. ..………….. offspring phenotypes ..………….. ..………….. ..………….. ..………….. probability of offspring having vestigial wings ..…………… [5] (ii) State the genotype of a pure-breeding fruit fly that has normal wings. … [1] (iii) The binomial name for a fruit fly is Drosophila melanogaster. State the genus of this fruit fly. … [1] [Total: 10]

4(a)(i) changing the genetic material of an organism ; by, removing / changing / inserting, (individual) genes ; 2 4(a)(ii) any one from: (insertion of human genes) into bacteria, to produce human insulin ; (insertion of genes into crop) plants, to confer resistance to herbicides ; (insertion of genes into crop) plants, to confer resistance to insect pests ; (insertion of genes into crop) plants, to provide additional vitamins ; AVP ; e.g. named examples 1 AW throughout 4(b)(i) parental genotypes: AA and Aa ; gametes: A A (×) A a ; offspring genotypes: AA, AA, Aa, Aa ; offspring phenotypes: all normal wings ; probability: zero ; 5 ecf for each subsequent row

5 (a) Complete the sentences using the words or phrases from the list. Each word or phrase may be used once, more than once or not at all. different from divide embryo gamete fuse fetus identical to meiosis mitosis zygote In sexual reproduction, each parent organism produces a sex cell called a … . These cells are produced by a type of cell division called … . The nuclei of two sex cells … to form a … in a process called fertilisation. The offspring are genetically … each other and their parents. [5] (b) Fig. 5.1 shows four examples of reproduction in living organisms. Q a sperm cell reaching an egg cell R a single bacterial cell dividing S a strawberry plant with offspring connected by a runner T an insect pollinating a flower Fig. 5.1 State the two letters in Fig. 5.1 that identify examples of asexual reproduction. … and … [2] (c) Fig. 5.2 is a diagram showing all of the chromosome pairs in a cell from a human male. The twenty-third pair of chromosomes are the sex chromosomes. Fig. 5.2 Describe how the chromosomes in a human female differ from those shown in Fig. 5.2. … … … [1] (d) Describe how insect-pollinated flowers are adapted for pollination. … … … … … … … … … [4] [Total: 12]

5(a) gamete ; meiosis ; fuse ; zygote ; different from ; 5 5(b) R ; S ; 2 5(c) female will be XX (and male is XY )(chromosomes) / sex chromosomes will ,be the same / look the same ; 1 5(d) any four from: large petals ; colourful / bright, petals ; scented ; nectar / nectaries ; anthers / stigmas, inside the flower ; sticky / spiky, pollen grains ; less pollen made (than wind pollinated) ; AVPs ;; e.g. larger / heavy, pollen grain 4 6(a)(i) carbon dioxide + water → ; glucose + oxygen ; 2

32 What is defined as ‘a thread-like structure of DNA, carrying genetic information in the form of genes’? A allele B chromosome C protein D zygote

Answer: B To earn the mark, a student must correctly identify 'chromosome' as the thread-like structure of DNA carrying genetic information in the form of genes.

Cambridge IGCSE Biology · 0610

IGCSE Biology (0610) Inheritance past paper questions

Inheritance questions test chromosomes, DNA, mitosis and meiosis, and genetic crosses.

296 free questions from 2017–2021, each with its marking scheme. Open the full topical bank to filter by subtopic, paper, and year.

Inheritance in IGCSE Biology 0610 exams, 2020–2025

Across 2020–2025, Inheritance accounted for 310 questions worth 969 marks in Cambridge IGCSE Biology (0610) papers.

By year
Year	Questions	Marks
2020	54	170
2021	63	222
2022	52	188
2023	51	156
2024	38	120
2025	52	113

Most-tested subtopics

17.1 Chromosomes, genes and proteins416 marks
17.4 Monohybrid inheritance268 marks
17.3 Meiosis164 marks

Appears in

Paper 1 · 75 qs
Paper 2 · 170 qs
Paper 3 · 28 qs
Paper 4 · 37 qs

All most-tested Biology topics

2021 May/Jun · Paper 3 · Q3 · 10 marks
Marking scheme
Get Steven’s plain-English explanation
2021 Oct/Nov · Paper 3 · Q3 · 8 marks
Marking scheme
Get Steven’s plain-English explanation
2021 May/Jun · Paper 3 · Q4 · 10 marks
Marking scheme
Get Steven’s plain-English explanation
2021 Oct/Nov · Paper 3 · Q5 · 12 marks
Marking scheme
Get Steven’s plain-English explanation
2021 Feb/Mar · Paper 1 · Q32 · 1 mark
Marking scheme
Mark scheme — 2021 Paper 1 Q32
Answer: B
Get Steven’s plain-English explanation