16.3. Sexual reproduction in plants
A subsection of Biology, 0610, through 16. Reproduction
Listing 10 of 316 questions
Anthocyanin is a red pigment found in carnation flowers. Some carnation plants have a gene for making anthocyanin. A flower grower bred red carnations. Describe how growers selectively breed plants. Explain the disadvantages of using sexual reproduction to breed red carnations. Meiosis is necessary for sexual reproduction of carnation plants. Define the term meiosis. [ 1 10 Carnation plants show co-dominance for the anthocyanin gene. There are two alleles: • FA – allele for anthocyanin pigment (red flowers) • FN – allele for no anthocyanin pigment (white flowers) State the genotype of a carnation plant that is heterozygous for this gene. Describe the phenotype of a heterozygous carnation plant for this gene. The breeder crossed a FAFN carnation plant with a FAFA carnation plant. Predict, using a genetic diagram, the proportion of pure breeding carnation plants in the offspring. parental genotypes FAFN gametes Punnett square FAFA × + offspring genotypes offspring phenotypes proportion of pure breeding carnation plants 1 10
0610_s16_qp_42
THEORY
2016
Paper 4, Variant 2
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Johnson grass, Sorghum halepense, is wind-pollinated. shows some Johnson grass flowers. State the genus of Johnson grass. Describe two features visible in that show that Johnson grass flowers are adapted for wind-pollination. shows a section through a carpel shortly after pollination. D A C B E State the names of the parts of the carpel labelled C, D and E. C D E Complete the sentences: Pollen grains are formed in anthers. During their formation the number of chromosomes in the nuclei is halved by the process of . This means the male nucleus A in the pollen tube is described as a nucleus. When nucleus A with nucleus B, the chromosome number doubles to form a nucleus. The name of this process is . Then the divides by the process of to form an embryo. Discuss the advantages of sexual reproduction to a wild population of flowering plants such as Johnson grass. Sexual reproduction requires energy. State three uses of energy in organisms other than in reproduction.
0610_s20_qp_41
THEORY
2020
Paper 4, Variant 1
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For Examiner's Use 10 Flowers from three red-flowered plants, A, B and C, of the same species were self- pollinated. Explain what is meant by the term pollination. Seeds were collected from plants A, B and C. The seeds were germinated separately and were allowed to grow and produce flowers. The colour of these flowers is shown in Table 10.1. Table 10.1 seeds from plant colour of the flowers grown from the seeds A all red B some red and some white C some red and some white State the recessive allele for flower colour. State which plant, A, B or C, produced seeds that were homozygous for flower colour. Suggest how you could make certain that self-pollination took place in the flowers of plants A, B and C. For Examiner's Use Complete the genetic diagram to explain how two red-flowered plants identical to plant B could produce both red-flowered plants and white-flowered plants. Use the symbols R to represent the dominant allele and r to represent the recessive allele. parental phenotypes parental genotypes gametes offspring genotypes offspring phenotypes parent 1 red-flowered parent 2 red-flowered × × +
0610_w11_qp_21
THEORY
2011
Paper 2, Variant 1
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shows a section through a flower. A B C E F G D Table 5.1 describes the functions of some parts of the flower. Complete the table using the label letters from . You may use each letter once, more than once or not at all. Table 5.1 function letter protection of the flower when in bud place where pollen is produced site of fertilisation a suitable landing site for pollen attracts insects Individual flowers of the same species can be different colours. is a genetic diagram which shows how colour is inherited for one particular species. R represents the allele for red flower colour. r represents the allele for white flower colour. Complete using words from this list. Each word may be used once, more than once or not at all. dominant gametes genotypes heterozygous homozygous phenotypes recessive red parental × white RR parental rr all R all r all Rr F1 all red F1 The F1 red flowers were pollinated with pollen from white flowers. State the proportion of red to white flowers you would expect in the offspring from this cross.
0610_w14_qp_21
THEORY
2014
Paper 2, Variant 1
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shows a common emerald dove, Chalcophaps indica. Two distinguishing features of birds are beaks and wings. State one other feature shown only by birds that is visible in . Birds show variation in the sizes and shapes of their beaks. A beak is composed of an upper mandible and a lower mandible. shows the heads of seven different species of bird. A C E G D F B lower mandible upper mandible width of head not drawn to scale Use the key to identify each species. Write the letter of each species (A to G) in the correct box beside the key. One has been done for you. key beak is shorter than the width of the head go to 2 beak is longer than the width of the head go to 4 upper mandible is same length as the lower mandible Spinus tristis upper mandible is longer than the lower mandible go to 3 lower mandible is about half the length of the upper mandible Ara ararauna A lower mandible is more than half the length of the upper mandible Aquila chrysaetos both mandibles widen at the end of the beak Platalea regia both mandibles are a similar width along their whole length go to 5 beak is straight Trochilus polytmus beak is curved go to 6 beak curves upwards Recurvirostra americana beak curves downwards Phoenicopterus minor shows the events that occur during sexual reproduction in birds. The numbers in brackets indicate the number of chromosomes in the nuclei of the cells of the common emerald dove. adult male (80) adult female (80) process A process A sperm (40) cell B (80) embryo (80) hatching young bird (80) egg (40) Name process A and cell B. A B State why cell B is described as a diploid cell. The embryo of the bird develops from cell B. State what is meant by the term development. Sexual reproduction usually leads to variation. Explain why variation is an advantage for a species such as the common emerald dove.
0610_w15_qp_32
THEORY
2015
Paper 3, Variant 2
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Questions Discovered
316