chapter 19-21 - 在线考试测评模板

Q1:Grade/class/name

填空1

Q2:Which name is given to the observable features of an organism

A.alleles

B.genes

C.genotype

D.phenotype

Q3:What is not a feature of natural selection

A.competition for resources

B.production of many offspring

C.selection by humans

D.variation within the population

Q4:What is a mutation

A.a change in a gene or chromosome

B. a condition caused by a dominant allele

C.a process used in genetic engineering

D.a type of continuous variation

Q5:The table shows the birth rates and death rates in four countries.Which country will double its population most quickly?[图片]

A.选项1

B.选项2

C.选项3

D.选项4

Q6:By which process does water enter the atmosphere?

A.condensation

B.photosynthesis

C.precipitation

D.transpiration

Q7:Which characteristic shows discontinuous variation in humans

A.height

B.length of foot

C.tongue rolling

D.weight

Q8:A man who was blood group A and a woman who was blood group B had four children, each witha different blood group A, B, AB and O.Which type of variation does this demonstrate?

A. continuous, environmental and genetic

B.continuous and genetic only

C. discontinuous, environmental and genetic

D.discontinuous and genetic only

Q9:Cacti have fewer stomata than other plants.How does this help them to survive in desert conditions?

A.It increases loss of water.

B.It increases uptake of carbon dioxide.

C.It reduces loss of water

D.It reduces uptake of carbon dioxide

Q10:A food chain shows how organisms depend on each other for their sources of energy, but allenergy comes ultimately from one source.What is this energy source?

A.leaves of plants

B. meat

C.sunlight

D.water

Q11:The diagram shows a food web.[图片]What type of organism is X?

A.a carnivore

B.a decomposer

C.a herbivore

D.a producer

Q12:What is the correct sequence for the stages in a sigmoid population growth curve?

A. lag → log → stationary

B.log → lag → stationary

C.stationary → lag → log

D.stationary→ log → lag

Q13:In an ecosystem, what happens to most of the chemical energy in the decomposers?

A.It is transferred back to the producers.

B.It becomes heat.

C.It is transferred back to both producers and consumers.

D.It is destroyed

Q14:In a pyramid of numbers, what does the top of the pyramid represent

A.carnivores

B.decomposers

C.herbivores

D.Sun

Q15:Rabbits eat grass and foxes eat rabbits.What would cause the highest increase in the number of rabbits?

A.less grass and fewer foxes

B.less grass and more foxes

C.more grass and fewer foxes

D.more grass and more foxes

Q16:The diagram shows a food chain.rice plant → caterpillar → song bird → hawkHow many decomposers are shown in this food chain?

A. 0

B. 1

C. 3

D. 4

Q17:which enzyme is used to cut the DNA into disirable pieces? ______ enzyme

填空1

Q18:which enzyme is to join two fragements of DNA together?

填空1

Q19:there is a cricular DNA that can be frequently used in gene engineering becasue of its transferring ability between different bacteria. it is called _____

填空1

Q20:the enzyme peptidase is used to breakdown the cell wall of plant cell and make clear juice.

是

否

Q21:which products of fermentation (anaerobic respiration in yeast) are important in the production of bread and beer[图片]

A.选项1

B.选项2

C.选项3

D.选项4