主效基因抗病性（major gene resistance）

A.Marfan syndrome is due to mutations in the gene encoding fibrillin-1, a major constituent of microfibrils.

B.All cases of Ehlers–Danlos syndrome are due to mutations affecting the genes encoding the various types of collagen.

C.Laminin is found in renal glomeruli along with entactin, type IV collagen, and heparin or heparan sulfate.

D.Mutations affecting type IV collagen can cause serious renal disease.

E.Mutations in the collagen 1A1 gene can cause osteogenesis imperfecta.

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A.Eventually， a commercial plant was developed which was 5 percent sweeter than before，but also much stronger and less likely to die from disease.

B.One major gene has been identified by Dr Angelique D"Hont and her team in Montpelier，France.

C.Sugar cane is now much more vigorous and the supply of sugar is therefore more guaranteed.

D.Since the 1960s， scientists have been analyzing the mysteries of the sugar cane"s genetic code.

E.The majority of the world"s sugar now comes from this particular commercial species.

F.Unfortunately， however， the plant started to become weaker and more prone to disease.

A.主效基因抗病性

B.单基因抗病性

C.寡基因抗病性

D.多基因抗病性

【填空题】AV Clip 7:cause3 Is Autism GeneticAV 7.mp4 Watch the video clip three times and complete each statement according to the information from the video clip. So is autism a (1) ____________________？ Now this is something that has been researched and they are definitely genetic conditions that are associated with autism. Something like (2) __________________X. And that is a testing that is done in children often diagnosed with autism. It is rare but there's an abnormality in the (3) ____________________being transmitted. That is an issue in some children, however, this is a very small (4) ___________________of children who get diagnosed with autism who actually have a fragile X problem. There are other medical conditions which are genetically known but the understanding is that it is not one gene, but there are (5) _______________ genes and it's probably a host of little differences whether you call them denovo (6) _________________or changes that take place, or single nucleotide polymorphisms called snips, which can contribute and work together as a (7) ______________to cause a difference in the immune system, in themethylation cycles and in so many other areas that are important in the neurochemistry and the neurobiology of the brain. So there is underlying genetic differences and it is interesting that some of the genes that have been associated with autism are also involved with (8) ______________function, with immune function and a huge amount of research is coming out in this area. Something simple not just with major genes but genes that code for (9) ______________this is going to get a little complex as I use words like the creation of folic acid has to be converted to folinic acid and you need MTHFR, methyltetrahydrofolate reductase, which is an enzyme that converts the (10) ____________acid to folinic acid. And children with the autism spectrum often can have one or two of the LLS, or pieces missing in the creation of this enzyme and if this enzyme is not working effectively you may have some issues in the creation of folic acid which you need for your brain and for a neurotransmitter functioning which is important for the creation of dopamine, serotonin, norepinephrine... I'm going into major chemistry here but that's what genetics involves. So it's not just a simple gene but it's a cascade of genes and it's not just the major genetics, the major chromosomes that we're talking about but the sub areas the DNA creation of even enzymes and the genetic variations at that level that may be involved or that are involved and need to be researched and worked with in children with an autism spectrum disorder.

ox discovered the gene(基因)that causes cystic fibrosis (膀駫纤维症) (CF).Many geneticists consider it’s one of the most significant discoveries in human genetics. The results of Fox work have helped scientists develop tests that identify carriers of the CF gene. They hope his research could cure CF.A test has been developed to identify people carrying the cystic fibrosis gene.The test is based on knowing where the gene is located.The CF gene is a recessive gene. This means a person can carry one copy of the gene and still not be affected by the disease. However, if this person has children with another person who carries the CF gene, there is a 25% chance that their children will inherit two copies of the gene and suffer from the disease. The test identifies whether parents carry the defective CF gene. Researchers are also using Fox discovery to find a cure for cystic fibrosis. They are working to produce a drug that will change the activity of the CF gene and also attempting to replace the defective gene with one that functions properly. It is difficult to produce a drug that changes the CF gene, but does not affect the 100,000 other genes of human. But Fox discovery has at least given a chance for the cure of the CF

1.We can find answers to the following questions in the passage except ().

A.Do people with CF live longer than they did in the past

B.Describe the effects of CF.

C.Evaluate the current methods used to treat CF

D.Describe the drugs used to treat CF

2.The best title for the passage would be ().

A.Why People Have CF

B.The Drugs Used to Treat CF

C.The Methods of Curing CF

D.The Significance of the Discovery Cystic Fibrosis Gene

3.The word ‘recessive’(line 6) probably means ().

A.hidden

B.concealing

C.faint

D.covered

4. The following statements are true except ().

A.Only one quarter of people will have chance to have the disease.

B.Fox discovery help scientist develop tests that identify carriers of the CF gene.

C.Scientist has already produced a drug to cure CF.

D.To produce a drug is not easy because it should changes the CF gene but not affect others

5.A person with () of a harmful recessive gene will be affected.

A.one copy

B.two copies

C.no copies

D.three copies

根据下面短文内容，回答题。

The Tough Grass that Sweetens Our Lives

第46题___________ 查看材料

A.Eventually， a commercial plant was developed which was 5 percent sweeter than before，but also much stronger and less likely to die from disease.

B.One major gene has been identified by Dr Angelique D"Hont and her team in Montpelier，France.

C.Sugar cane is now much more vigorous and the supply of sugar is therefore more guaranteed.

D.Since the 1960s， scientists have been analyzing the mysteries of the sugar cane"s genetic code.

E.The majority of the world"s sugar now comes from this particular commercial species.

F.Unfortunately， however， the plant started to become weaker and more prone to disease.

1. In tomato, the round fruit (R) is dominant to pear shape(r), while the single flower (B) is dominant to multiple flowers (b). Now using double homozygotes as parents, we get F1 generation. F1 testcrosses with the double recessive homozygotes, the following progenies were obtained: Round, single flower 34, Round, multiple flowers 214 Pear, single flower 216, Pear, multiple flowers 36 Question: (1) Are gene R and B linked？ (2) What are the genotypes of the two homozygous parents？ (3) If the two genes linked, what is their genetic distance？ If the two genes not linked, please write out the genotype of F1.