39112441
Descripción
| Pregunta | Respuesta |
| 1. parents are BB and bb 2. first generation is Bb | |
| 1. gametes B and b 2. second generation BB, Bb, Bb and bb | |
| 1. sperm 2. fertilisation 3. zygote 4. diploid 5. mitosis 6. 40 / 20 pairs | |
| How many chromosomes are shown in this photograph? | 47 |
| State the sex of the person the chromosomes were taken from. | male |
| Describe how the chromosomes in the photograph differ from those found in a typical human body cell. | has an extra chromosome 2. (which is) sex chromosome / Y |
| The rare condition leads to the formation of abnormal sperm cells. (i) Name the cell division that produces sperm cells. | meiosis |
| Suggest how an individual with the chromosomes shown could be produced. | 1. failure of chromosomes to separate 2. (gamete) has an extra chromosome 3. normal egg / gamete fertilised by abnormal sperm |
| 1. source of food / source of nutrients 2. smell | |
| Describe two differences between selective breeding and natural selection. | 1. sp erm; 2. fertilisation / fusion; 3. zygote; 4. diploid; 5. mitosis; 6. 40 / forty / 20 pairs; |
| Farmers sometimes use pesticides to prevent flies attacking sheep. Give two problems with the use of chemical pesticides. | They may kill pollinating insects, harming the lifecycle of plants, especially crops. They may be harmful to the sheep, or damage the sheep’s wool. |
| The passage describes selective breeding. Complete the passage by writing a suitable word in each of the spaces. Selective breeding involves ___ choosing organisms with desired ___. These organisms are allowed to breed and produce ___ . The process is ___ for several generations. | Selective breeding involves HUMANS choosing organisms with desired CHARICTERISTICS. These organisms are allowed to breed and produce OFFSPRING . The process is REPEATED for several generations. |
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