user-avatar
danh03052005
2 năm trước
trong một cơ thể gà mái 2n=78 xét một tb sinh duc sơ khai nguyên phân liên tiếp 6 lần để tạo ra các tb con. các tb con tạo ra đều trải qua quá trình sinh trưởng nhưng chỉ có 50% số tb này qua vùng chín thực hiện giảm phân tạo giao tử. cho rằng không có đột biến và số giao tử này tham gia thụ tinh với hiệu suất 25%. theo lí thuyết, hãy xác định số hợp tử được tạo thành giúp e vs ạ , e đang cần gấp
Thích Trả lời Chia sẻ

Các câu hỏi liên quan

Làm + Giải thích giúp mk vs 1. I'm absolutely no good at al ......... any kind of sport A. with B. on C. at D. for 2. ................ exhibitions are like huge marketplaecs for the sale of goods, and these are often called trade fairs A. Any of B. A great many C. A great amount of D. A lot of 3. Well, it was so dark and.............. A. we could see the road signs hardly B. hardly could we see the road signs C. we could see hardly the road signs D. we could hardly see the road signs 4. Mr. Brown is bored..............,,,,,, doing the same job for too long A. at B. if C. when D. whereas 5. to people in Africa, Asia, and South America, English is an important language................ A. for mastering B. to master C. which is mastered D. that is for mastering 6......................... does it take you to drive to your office A. How B. How far C. How often D. How long 7. He now feels sorry...............what he has done A. of b. for c. at D. with 8. Narcissus bulbs........................at least three inches apart and covered with about four inches of well-drained soil A. should be planting B/ should be planted C. must plant D. may plant 9. Wherever there is plenty of rain during the growing seasons, life is.......................in various forms A. an abundant B. the abundance C. abundant D. it abundant 10. If it's raining tomorrow, we shall have to...................the match till sunday A. put off B. call off C. keep on D. carry out

B. GRAMMAR AND VOCABULARY Question I: Circle the best option A,B,C or D to complete each of the following sentences. 1. Another name for Wales is _____________. A. Saxon B. Celtic C. Cymru D. Galle 2. You can see _____________ on the Canadian national flag. A. the maple leaf B. the red leaf C. the rose D. the oak tree 3. In 1893, _____________ became the first country in the world to give all women the right to vote. A. Canada B. New Zealand C. America D. Singapore 4. ____________ has a unique culture with traditions such as bagpipes, kilts and highland dancing. A. England B. Wales C. Scotland D. Northern Ireland 5. The name “Australia” comes from the Latin word “australis”, meaning ____________. A. northern B. southern C. eastern D. western 6. The tallest mountain the US is Mt McKinley, located in the state of _______. It reaches 20,320 feet (6,194 m) above the sea level. A. Alaska B. California C. Florida D. Washington 7. The Lord of the Rings movies were filmed in ____________. A. England B. Australia C. Canada D. New Zealand 8. Scotland only shares a border with ______________. A. Wales B. Northern Ireland C. England D. Britain 9. The name Canada comes from the word “kanata” which means “settlement” or “____________” in the language of the St Lawrence Iroquoians. A. country B. village C. town D. nation 10. The world’s largest reef system, the Great Barrier Reef, is found off the north-eastern coast of ______________. A. Canada B. America C. New Zealand D. Australia 11. The Statue of Liberty in New York is a monument which freedom. A. symbolised B. is symbolised C. symbolising D. symbolises 12. Scotland is in the of Great Britain . A. east B. north C. west D. south 13. People in countries like the USA, Great Britain, and New Zealand use English as their language. A. native B. mother C. official D. foreign 14. A: After the typhoon, many houses and public buildings were destroyed or flooded. - B: A. That’s awful! B. that’s good! C. That’s a relief! D. That’s great! 15. Yesterday, a terrible storm the rural area of Thanh Hoa Province. A. erupted B. hit C. butied D. collapsed 16. I think, the from factories has polluted the lake. A. smoke B. waste C. soil D. air 17. People cough they breathe in the fumes from cars. A. so B. but C. because D. and 18. People get more diseases because the water is A. clean B. pollute C. contaminated D. poison Question II: Supply the correct form or tense of the verbs in brackets. 1. In Canada, New Year’s Day ____________ a long tradition of celebration. (have) 2. First names ____________ used more frequently in Australia than in other countries. (be) 3. Recently, many places in New Zealand __________ called with two names – one English, one Maori. (be) 4. Maori people ___________ the hongi – touching noses – to greet people they _________ safe and familiar with. (use-feel) 5. Since its beginning more than a century ago, the slouch hat ___________ one of the most distinctive items of Australian clothing. (become) 6. For over 130 years, Akubra hats ___________ its legendary stories in Australia. (make) 7. Aberdeen in Scotland _____________ an important centre for the oil industry since the finding of oil in the North Sea. (become) 8. Canada ___________ the longest land border in the world with the United States. (share) 9. Ireland ___________ the Eurovision Song Contest seven times. (win) 10. In Canada you should maintain eye contact while you __________ lands. (shake) 11. If we recycle more, we ______________ (help) the Earth. 12. I ______________ (grow) some vegetables If we had a small garden at our house. 13. The bus for the excursion to the chocolate factory ______________ (leave) at 8.00 on Monday. 14. Most people ______________ (move) away before the vocalno erupted. 15. Many houses and offices ______________ (destroy) when the rescue workers came. Question III: Fill in each blank with a suitable preposition to complete the sentences. 1. __________________ habitats have been destroyed in recent years. (nature) 2. A number of cleaning products contain ______________ chemicals. (harm) 3. Water samples collected at these villages were seriously ______________ with bacteria. (contaminate) 4. People believe that the _____________ water has brought cancer to the local residents. 5. Light pollution makes us _____________ to see the stars in the sky. (able) 6. Noise is considered as ______________ pollution. (environment) 7. I will join an _____________ summer camp this vacation [NATION] 8. Tsunami is a Japanese term for an unusually large ocean wave caused by undersea earthquake, landslide, or volcanic _____________ . [ERUPT] 9. A kilt is the _____________ garment for Scottish men. [TRADITION] 10. Natural disasters can be _____________. [DESTROY]

2018 © Loga - Không Ngừng Sáng Tạo - Bùng Cháy Đam Mê
Loga Team