DNA, Genes and Chromosomes 0.0 / 5 ? BiologyDNA and inheritanceGCSEAQA Created by: AmberCoombesCreated on: 15-11-15 15:29 What are DNA molecules? DNA molecules are large and complex and they carry the genetic code that makes up the characteristics of a living organism 1 of 13 What is a gene? A genes is a sections of DNA that codes for a specific protein. A gene is hereditary and may be passed down to the next generation 2 of 13 What are different versions of the same gene called? Different versions of the same gene are called alleles 3 of 13 When is a dominant allele expressed? A dominant allele is always expressed even if there is only one copy of it e.g brown eyes is dominant 4 of 13 When is a recessive allele expressed? A recessive allele is only expressed if the individual has two copies e.g blue eyes is recessive 5 of 13 What is diploid? Diploid is a cell that contains two sets of chromosomes 6 of 13 What is mitosis? Mitosis produces two genetically identical cells in which the number of chromosomes is the same as the original cell 7 of 13 In mitosis, why do chromosomes have to be copied exactly? Chromosomes have to be copied exactly so that new cells can be produced for growth, repair to damaged tissue and replacement of warn out cells 8 of 13 What is meiosis? Meiosis is the type of cell division that produces gametes and it produces 4 genetically different haploids 9 of 13 How many chromosomes does the human body cell contain? The human body cell contains 46 chromosomes (23 pairs) 10 of 13 Are human cells haploid or diploid? Human cells are haploid 11 of 13 What is meiosis used for? Meiosis is used for producing gamete for sexual reproduction 12 of 13 What is mitosis used for? Mitosis is used for growth, repair and asexual reproduction 13 of 13
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