QCE Practice Questions for Unit 3 & 4 Biology External Assessment

Question 6

Describethe carbon cycle(3 marks)

Question 7

Explainwhy the biological definition for species is limited(2 marks)

Question 8

(a)Definethe term carrying capacity(1 mark)

(b)Explainhow population size is limited by the carrying capacity(2 marks)

Question 9

Scientists wanted to monitor the population growth of a species of bacteria. The bacteria was left in a petri dish and the following data was collected:

Time (hours)	Number of Bacteria
0	2
1	4
3	16
4	52
5	110
6	214
7	430
8	870
9	1740
10	1860
11	1740
12	1860

(a)Construct a graph of the results(1 mark)

(b)Identifythe carrying capacity(1 mark)

(c)Identifythe mode of population growth(1 mark)

Question 10

Identifythe four features of pioneer species that make them effective colonisers(4 marks)

Question 11

Comparethe roles of helicase and DNA polymerase in DNA replication(2 marks)

Question 12

Explainthe importance of independent assortment and random fertilisation for ensuring genetic variation in offspring(2 marks)

Question 13

Blue eyes are a recessive trait. Individuals who are heterozygous for the gene will not exhibit the trait in their phenotype but are said to be carriers of the trait.

(一)构建一个潜在o庞氏表ffspring of an individual who is heterozygous (carrying the genes for brown and blue eyes) and an individual who is homozygous for the recessive trait(2 marks)

(b)Determinethe genotypes and phenotypes of the offspring(4 marks)

Question 14

Explainthe process, occurring during protein synthesis, during which genes are transcribed into messenger RNA(3 marks)

Question 15

Based on the karyotype below:

Image sourced fromUNSW Embryology

(a)Identifythe abnormality in this assortment of chromosomes(1 mark)

(b)Determinea potential cause for this mutation(2 marks)

Question 16

(a)Definethe aneuploidy(1 mark)

(b)Explainhow aneuploidy is a result of non-disjunction(2 marks)

Question 17

Describethe process of making recombinant DNA(5 marks)

Question 18

(a)Definethe term evolution(1 mark)

(b)Contrastmicro- and macroevolution(4 marks)

Question 19

Explainhow genetic drift leads to microevolution(2 marks)

Question 20

Recalltwo of the four diversification patterns between species(4 marks)

Question 21

Explainhow population bottlenecks increase the risk of extinction(2 marks)

Question 22

Using the following table:

Species	Number of Individuals
1	81
2	2
3	2
4	2
5	2
Total	89

Calculatethe Simpson’s Diversity Index for this location(2 marks)

Question 23

Explainhow chemical mutagens result in mutation(2 marks)

Question 24

ExplainK- and r-selection(4 marks)

Question 25

Definethe term genome(1 mark)

Solutions to QCE Biology EA Practice Questions

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