Flashcards
B2.5 Flashcards
Flashcards do conjunto (21)
- 1Which type of cell division produces two identical cels from the original cell?Mitosis
- 2What type of cells are produced by meiosis?Sex cells or gametes, eggs and sperm
- 3Explain how four gametes are formed from one cellThere are two sets of cell division. A body cell divides into two each divides again
- 4Where are stem cells found in adult humans?Bone marrow
- 5Which scientist worked out how characteristics are inherited?Mendel
- 6What does a gene code for?The order of amino acids in a protein
- 7Which sex chromosomes are found in human males?X and Y
- 8What is meant by the term 'phenotype'?This is a description of the physical characteristics
- 9Name a genetic disorder which is controlled by a dominant allelePolydactyly
- 10What are the chances of a child having cystic fibrosis if one parent has the disorder and the other parent is heterozygous?50%, as one parent (cc) has to pass on the allele, the other parent (Cc) has a 50% risk of passing it on; the child is either Cc or cc
- 11What is embryo screening?Tests are carried out on the embryo to diagnose possible disorders
- 12Why do cells divide by mitosis?To produce identical cells for growth and to replace cells
- 13How many chromosomes does a human have in each body cell?23 pairs (or 46)
- 14Which type of cell division produces sex cells?Meiosis
- 15What molecule are genes made of cells?DNA
- 16What are 'alleles'?Different forms of a gene
- 17Why does sexual reproduction result in variation?The genetic material from two parents is brought together when the sperm and egg nuclei fuse
- 18Explain why offspring produced by asexual reproduction are genetically identicalThey are produced by mitosis. Cells from one parent divide to produce identical cells
- 19What is meant by the term 'genotype'?The types of genes present in the cells
- 20What do we mean by a 'heterozygous' individual?The individual has one dominant and one recessive allele for a condition
- 21What are the chances of a child having polydactyly if one parent is heterozygous and the other parent is homozygous recessive?50%, as the dominant gene controls the condition; a child has a 50:50 chance of inheriting the allele from the heterozygous parent
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- GCSE Biology (Unit 2) FlashCards sobre B2.5 Flashcards, criado por Mel Hughes em 31-08-2016.
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- Mel Hughes
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