1. Instructions for cell division and inheritance cooperative learning (Kagan) activity Activity for consolidation of key terminology and revision suitable for higher tier students AQA B2.7 Cell division and inheritance and OCR gateway Quiz Quiz Trade Preparation Print the following slides onto card or laminate. Cut out the cards along the thick lines. 1. Each pupil is given one card. 2. Each card has key information about the topic and a question with an answer. 3. Pupils will need to move around the room with the intention of swapping cards with as many other pupils as possible. 4. Pupils pair up and pupil 1 reads out the information on their card followed by the question. Pupil 2 must then answer the question correctly. If answered incorrectly pupil 1 must guide pupil 2 towards the correct answer. Once the correct answer has been given the roles are reversed. 5. Once pupils have both given a correct answer, they trade cards and move on to make a new pair and repeat the process.

2. Information: Sexual reproduction gives rise to variation because, when gametes fuse, one of each pair of alleles comes from each parent. The number of chromosomes in a human gamete (sex cell) is half the number in body cells. Information: Cells in reproductive organs – testes and ovaries in humans – divide to form gametes. This type of cell division is called meiosis. Information: A gene is a small section of DNA. Question: What is the number of chromosomes in a human gamete (sex cell)? (1 mark) Question: Gametes are produced by: a)fertilisation b)meiosis c) mitosis (1mark) Question: Gametes are produced by: a)fertilisation b)meiosis c) mitosis (1mark) Answer: 23 chromosomesAnswer: b) meiosis Information: Some characteristics are controlled by a single gene. Each gene may have different forms called alleles. Information: An allele that controls the development of characteristics only if the dominant allele is not present is a recessive allele. Information: An allele that controls the development of a characteristic when it is present on only one of the chromosomes is a dominant allele. Question: Question: Our understanding of how genes are inherited is mostly because of the work of : (1 mark) a) Darwin b) Lamarck c) Mendel Question: Cystic fibrosis is caused by: a) Thick, sticky mucus b) A recessive allele c) A dominant allele Question: In a genetic diagram, how is a dominant allele shown? Answer: c) MendelAnswer: b) a recessive alleleAnswer: as a capital letter

3. Information: Mitosis occurs during growth or to produce replacement cells. When a body cell divides by mitosis: copies of the genetic material are made and then the cell divides once to form two genetically identical body cells. Information: In human body cells, one of the 23 pairs of chromosomes carries the genes that determine sex. In females the sex chromosomes are the same (XX); in males the sex chromosomes are different (XY). Question: As a result of mitosis, how many cells are produced? Question: What are the sex chromosomes in the human male ? (1 mark) Question: What are the sex chromosomes in the human female? (1 mark) Answer: two cellsAnswer: X and YAnswer: X and X Information: Chromosomes are made up of large molecules of DNA (deoxyribonucleic acid) which has a double helix structure. Information: In body cells the chromosomes are normally found in pairs. Body cells divide by mitosis. The chromosomes contain the genetic information. Information: Different forms of the same genes are called alleles. When there are two different alleles, one is stronger than the other. This is the dominant allele. It masks the effect of the recessive allele. Question: A gene is a small section of: Cellulose? DNA? Or Protein? (1 mark) Question: Most human body cells contain: 23 chromosomes, 46 chromosomes or 92 chromosomes. (1 mark) Question: A homozygous black mouse mates with a homozygous brown mouse, all the offspring are black. Why are no brown offspring produced? Answer: DNAAnswer: 46 chromosomes Answer: The allele for black fur is the dominant allele. The allele for brown fur is recessive and its effects are masked by the dominant allele.

4. Information: Homozygous - Having the same alleles at a particular gene on a chromosome. Information: The sex organs make sex cells or gametes. In male animals the sex cells are called sperm. In the female animal the sex cells are called eggs. Information: Mitosis is a kind of cell division. All cells are made from mitosis except the sex cells (gametes). The daughter cells produced are all identical to the cell that they came from. Question: B represents Brown eyes, little b represents blue eyes. What would the homozygous genotype be for someone with brown eyes? Question: How are sperm cells adapted to their function? Question: After a human egg has been fertilised, what type of cell division takes place? How many chromosomes would be present in each of the new cells? Answer: BB Answer: Streamlined shape, Tail to swim, Acrosome producing enzymes to digest cell membrane Answer: Mitosis takes place after fertilisation. Each cell would contain 23 pairs of chromosomes. Information: Meiosis is a kind of cell division. Sperm and egg cells are made by meiosis. Meiosis halves the number of chromosomes in the daughter cells Information: Humans have 23 pairs of chromosomes. The 23 rd pair is called the sex chromosomes. These determine whether you are a boy or a girl. If you are a girl, your sex chromosomes look alike. You will have two identical X chromosomes (XX). If you are male one chromosome will be shorter than the other. You will have one long X chromosome and one short y chromosome (XY). Information: genotype – the alleles passed on to the next generation Question: How many chromosomes would you expect to find in human sex cells? Explain your answer. Question: Mr and Mrs Cross have three children, all boys. They are sure that their next child will be a girl. Do you agree? Give the reason for your answer. You may draw a diagram to help you explain. Question: B represents brown eyes, and b represents blue eyes. What would be the genotype of someone with blue eyes. Answer: There are 23 chromosomes in a human sex cell. When fertilisation takes place, the fertilised egg will have 23 chromosomes from the mother and 23 from the father. This gives 46 in total. Answer: No I do not agree. They have an equal chance of having a boy or a girl The diagram below illustrates this X Y X XX XY Answer: bb

5. Information: Heterozygous - Having dissimilar alleles that code for the same gene or trait. Information: haploid: the number of chromosomes in a gamete, in humans, 23 Information: phenotype - observable characteristics Question: B represents Brown eyes, little b represents blue eyes. What would the heterozygous genotype be for someone with brown eyes? Question: Why do gametes contain half the number of chromosomes of a normal cell Question: B represents brown eyes, b represents blue eyes. What phenotype would someone with Bb have. Answer: BbAnswer: 2 gametes join together at fertilisation to give offspring with a new full set of unique DNA. Answer: Brown eyes Information: diploid: the number of chromosomes in a body cell, in humans 46 Question: Why do chromosomes come in pairs? Answer: 1 of each pair from mum and 1 from dad