1.Dễ
What does DNA replication produce?
- AA new protein
- BOne mRNA molecule
- CTwo identical DNA molecules
- DFour different DNA molecules
2.Dễ
What does phloem carry in a plant?
- ACarbon dioxide from the air
- BWater from the roots only
- CChlorophyll to the stem
- DSugars made in the leaves
3.Dễ
What is phagocytosis?
- AA cell dividing into two identical daughter cells
- BA cell engulfing large particles such as bacteria
- CA cell releasing hormones by exocytosis
- DA cell taking in small droplets of fluid
4.Trung bình
Which statement best describes biological evolution?
- AMovement of animals to a new habitat each year
- BGrowth of an organism from a single zygote to a fully grown adult
- CChange in the body of one organism during its lifetime
- DChange in the inherited traits of a population over generations
5.Trung bình
What is the function of the pores in the nuclear envelope?
- AThey make ribosomal RNA for the cell
- BThey attach the nucleus to the cell membrane
- CThey let molecules such as mRNA pass in and out
- DThey let chromosomes leave the nucleus to be copied
6.Trung bình
How does facilitated diffusion differ from active transport?
- AIt moves only water and no other substances
- BIt needs no energy and moves substances down their gradient
- CIt needs ATP and moves substances against their gradient
- DIt works without any membrane proteins
7.Khó
Ignoring crossing over, how many different combinations of chromosomes can one person's gametes have because of independent assortment?
- A2 × 23, which is 46
- B46, one for each chromosome
- C23², about 529
- D2²³, about 8 million
8.Khó
Một vi khuẩn đơn lẻ phân chia mỗi 20 phút. Nếu không con nào chết, sau 2 giờ có bao nhiêu vi khuẩn?
- A32
- B128
- C64
- D12
Đáp án
- 1. C · Two identical DNA molecules
- 2. D · Sugars made in the leaves
- 3. B · A cell engulfing large particles such as bacteria
- 4. D · Change in the inherited traits of a population over generations
- 5. C · They let molecules such as mRNA pass in and out
- 6. B · It needs no energy and moves substances down their gradient
- 7. D · 2²³, about 8 million
- 8. C · 64
Lời giải đầy đủ từng bước: hãy luyện chủ đề này trên examproblems.com.