Đâu là ý nghĩa sinh học của hiện tượng thụ tinh kép ở thực vật hạt kín?
Tiết kiệm vật liệu di truyền (sử dụng cả 2 tinh tử)
Hình thành nội nhũ cung cấp chất dinh dưỡng cho cây phát triển suốt quãng đời của nó
Hình thành nội nhũ chứa các tế bào tam bội
Hình thành nội nhũ cung cấp chất dinh dưỡng cho sự phát triển của phôi vào thời kì đầu của cây con
Hãy suy nghĩ và trả lời câu hỏi trước khi xem đáp án
Ý nghĩa sinh học của hiện tượng thụ tinh kép ở thực vật hạt kín là: hình thành nội nhũ cung cấp chất dinh dưỡng cho sự phát triển của phôi vào thời kì đầu của cây con.
Đáp án D
Tài liệu "Bộ Đề Kiểm Tra Giữa Học Kì II - Năm Học 2023-2024 - Sinh Học 11" tổng hợp các đề kiểm tra từ các trường THPT trên toàn quốc, được biên soạn bám sát chương trình học. Đề thi bao gồm các dạng bài trắc nghiệm và tự luận, tập trung vào các nội dung trọng tâm: hấp thụ nước và muối khoáng ở thực vật, chuyển hóa vật chất và năng lượng, sinh trưởng và phát triển ở thực vật, và điều hòa sinh lý ở động vật.
Câu hỏi liên quan
Điền các cụm từ còn thiếu vào chỗ trống:
Chăn nuôi công nghệ cao là mô hình chăn nuôi ứng dụng những …nhằm …, tăng chất lượng sản phẩm và hiệu quả chăn nuôi.
Cơ quan có thẩm quyền cao nhất của Liên minh châu Âu là
Output của lệnh: print(1+ 2 + 3+ 4) là gì?
Read the following passage about Unconventional Teachers Who Changed Lives and mark the letter A, B, C or D on your answer sheet to indicate the best answer to each of the following questions from 23 to 30.
Traditional education focuses on textbooks, but some teachers go beyond these limitations. Mrs. Rodriguez transformed her classroom into a living laboratory. Her students conducted experiments with plants and simple machines. She believed hands-on learning creates deeper understanding than reading alone. When asked why she taught differently, she replied, "I want students to fall in love with discovery." Her methods helped struggling students improve and develop passion for science.
Mr. Jackson abandoned lectures for storytelling and role-playing. His students experienced history by acting out important moments. This approach made history come alive and helped them remember key information. One student said, "Before Mr. Jackson's class, I thought history was boring, but he showed us it's fascinating." He took classes to historical sites and invited veterans to share experiences. These connections helped students understand how past shapes our present.
In a remote village, Ms. Chen taught English without proper textbooks. She created materials using newspapers and song lyrics. Despite limited resources, her students achieved remarkable results through her dedication. "Learning should be joyful, not painful," she told questioning parents. Ms. Chen organized conversation clubs and pen pal exchanges. These activities gave students practical language skills and confidence to use English in real situations.
Coach Williams was a life mentor who taught valuable lessons through sports. He focused on teamwork and fair play rather than winning. Students who struggled academically often excelled in his class. "The playing field is where children learn who they truly are," he explained. He created inclusive activities for all students regardless of athletic ability. Many former students credit him with teaching life skills like resilience and cooperation that helped them succeed after graduation.
The word “conducted” in paragraph 1 is OPPOSITE in meaning to _________.
Trong một khu rừng nhiệt đới có các cấp độ tổ chức nào dưới đây?
Read the following passage about human life expectancy and mark the letter A, B, C or D on your answer sheet to indicate the best answer to each of the following questions from 23 to 30.
How long will a baby born today live? 100 years? 120 years? Scientists are studying genes that could mean long life for us all.
There are already many, many people who have passed the landmark age of 100. In fact, there are now so many healthy, elderly people that there’s a name for them: the wellderly. These are people over the age of eighty who have no major illnesses, such as high blood pressure, heart disease or diabetes.
There are many scientific studies of communities where healthy old age is typical. These include places like Calabria in southern Italy and the island of Okinawa in Japan. In Calabria, the small village of Molochio has about 2,000 inhabitants. And of these, there are at least eight people over a hundred years old. When researchers ask people like this the secret of their long life, the answer is almost always about food and is almost always the same: ‘I eat a lot of fruit and vegetables.’ ‘I eat a little bit of everything.’ ‘I neither smoke nor drink.’
In the past, scientists looked at things such as diet and lifestyle for an explanation of long life, but these days they are also looking at genetics. Researcher Eric Topol says that there must be genes that explain why people are protected from the effects of aging process. The new research into long life did scrutinize groups of people who have a genetic connection. One interesting group lives in Ecuador. In one area of the country there are a number of people with the same genetic condition. It’s called Laron syndrome. These people don’t grow very tall – just over one metre. But Laron syndrome also give them protection against cancer and diabetes. As a result, they live longer than other people in their families. Meanwhile, on the Hawaiian island of Oahu, there’s another group of long-lived men, Japanese-Americans. They have a similar gene to the Laron syndrome group.
Back in Calabria, researchers constructed the family trees of the 100-year-old people. They looked at family information from the 19th century to today. It is concluded that there are genetic factors that give health benefits to the men. This is a surprising result because generally in Europe, women live longer than men. So what really makes people live longer? It seems likely that it is an interaction of genes, the environment and probably a third factor – luck.
The word “scrutinize” in paragraph 4 is closest in meaning to _______.
Cho tập hợp A=[−2;2]. Tập hợp A∩N bằng
- Trong tự nhiên, silver có 2 đồng vị, trong đó đồng vị chiếm 56%. Tính số khối của đồng vị còn lại biết nguyên tử khối trung bình của silver là 107,88.
Chọn đáp án đúng?
Trong không gian Oxyz cho mặt cầu \((S):{{(x-1)}^{2}}+{{(y-2)}^{2}}+{{(z+1)}^{2}}=25\).
Điểm nào sau đây nằm trong mặt cầu \((S)\)?
Một xe chuyển động chậm dần đều với tốc độ đầu 36 km/h. Trong giây thứ 6 xe đi được 7,25 m. Tính quãng đường xe đi được trong giây thứ 8.
Chọn phát biểu sai.
Một nông dân định trồng đậu và cà trên diện tích 8 ha. Nếu trồng đậu thì cần 20 công và thu 3 000 000 đồng trên diện tích mỗi ha, nếu trồng cà thì cần 30 công và thu 4 000 000 đồng trên diện tích mỗi ha. Hỏi cần trồng mỗi loại cây trên với diện tích là bao nhiêu để thu được nhiều tiền nhất biết rằng tổng số công không quá 180?
- Cho tập hợp \(A = \left\{ {1;2;3;4} \right\},B = \left\{ {0;2;4;6} \right\}\). Mệnh đề nào sau đây là đúng?
Read the following leaflet and mark the letter A, B, C, or D on your answer sheet to indicate the option that best fits each of the numbered blanks from 7 to 12.
ANNOUNCEMENT OF CARDIFF BIKE RACE
We are going to take part in the Cardiff Bike Race. Please notice some important details:
• Time: 8 AM ___(7)___ the 22nd of September.
• Team’s Dress Code: You ___(8)___ your normal black T-shirts and shorts because another club uses those colors. Instead, we will wear blue.
• Snack Break: After twenty kilometres, there will be a ___(9)___ spot for snacks with some cake and orange juice.
• Prizes: ___(10)___ latest sport watches.
Let's pedal our way to victory!
While our main aim ___(11)___ people on their bikes, a benefit of the day is the fundraising ___(12)___. This is either direct sponsorship from company logos on the cycling shirts or our cyclists getting sponsored individually per mile.
Đặc điểm nổi bật của xã hội hiện nay là gì?
Theo sông suất, người ta chia điện trở làm mấy loại:
Nhiễm sắc thể có những chức năng nào sau đây?
Công nghệ được áp dụng trong mô hình trồng rau ăn lá thủy canh màng mỏng dinh dưỡng tuần hoàn NFT?
Read the following passage about online dating and mark the letter A, B, C or D on your answer sheet to indicate the best answer to each of the following questions from 23 to 30.
Psychologists have found many advantages and disadvantages to online dating. Among the many criticisms aimed at online dating, the most severe concern is its effects on people's self-esteem and mental health.
Swipe left or right is the main feature of popular dating apps, where users quickly look at profiles. However, this system is criticized for being superficial. A study showed that users often feel less satisfied with their appearance. Jessica Strübel found that after a while, users begin to feel less like unique, special individuals and more like they're disposable. This feeling leads to users becoming increasingly sensitive about their looks and bodies, heightening self-consciousness. Dating apps also added to the idea that there's always something better around the corner, which further pressures users into trying to appear more attractive.
Dating apps not only harm self-esteem but also alter perceptions of relationships. By accelerating the dating process, these apps encourage poor social behavior. For instance, it's not unusual for people to ignore "likes" and messages or to lose interest and cut off communication. This behavior would have been considered extremely rude in the past. But with online dating, it is a common reality.
Furthermore, thirty-five percent of users actually reported feeling pessimistic about dating. Only twenty-eight percent of surveyed users reported feeling hopeful after using a dating site or app.
The word it in paragraph 3 refers to _____.