Classification and biodiversity

Question 1

Distinguish between analogous and homologous structures and explain why analogous features are not considered evidence of common ancestry (3)

Answer 1

• analogous structures are different structures that perform a similar function
• homologous structures are similar sructures performing different functions
• analogous structures arise through convergent evolution

Question 2

What does the ‘tentative nature’ of classification mean (2)

Answer 2

• classification may change
• as more information becomes available

Question 3

Name a biological technique to confirm that organims are seperate species (1)

Answer 3

DNA hybridisation

Question 4

Explain how the results of Dna profiling tests have been udes to determine that these two species were most closley related (1)

Answer 4

• they would have more sequences in common

Question 5

State one characterisitic which is common to all vertebrates (1)

Answer 5

• possess internal skeleton
• backbone

Question 6

Explain why sampling should be conucted at random (1)

Answer 6

to eliminate sampling bias

Question 7

Explain what precautions must be observed during collection of terrestrial animal population (2)

Answer 7

• make sure that not of the animals are hurt or make them visible to predators
• not allowed animals to reintegrate into the population - 24hrs

Question 8

Describe one assumption that has to be made when using the results when collecting terrestrial animal population (1)

Answer 8

• no births
• no deaths
• no immigration or emmigration has occured between collecting samples

Question 9

State two variable which should bet controlled in a quadrat experiment (2)

Answer 9

• choose fields of similar size
• quadrats randomly placed to avoid bias
• similar abiotic factors ed moisture, light

Question 10

Explain in confidence in the conclusion could be improved when uing quadrats (2)

Answer 10

• increase number of quadrats used
• repeat experiment with other fields

Question 11

suggest why do farmers are encouraged to let fields lie fallow for several years (1)

Answer 11

species diversity increases when left to lie fallow

Question 12

Explain why limbs provide evidence for divergen evolution (1)

Answer 12

Evidence where structure has evolved from a common ancestor to perform a different function

Question 13

Using examples explain how natural selection has led to anatomical, physiological and behavioural adaptations in mammals (9)

Answer 13

• Darwin recognised that species changed
• Proposing the theory of natural selection to explain why it happened
• organisms overproduce offspring
• so that there is a large varaition of genotypes in population
• changes to environemental conditions bring new selection pressures through competition, predation / diseases
• only those individuals with beneficial alleles conferring a beneficial phenotype have a selective advantage eg white fur in arctic therefore are more likely to survive
• thee individuals then reproduce
• offspring are likely to inherit the beneficial alleles
• therefore the beneficial allele frequency increases with the gene pool
  Adaptations any good example so long as each type covered with advantages:
• anatomical - beak shape in finches able to exploit different food
• Physiological - haemoglobin with higher affinity for oxygen allowing llamas to live at high altitude
• behaviourals - nocturnal animals avoiding heat of the day

Question 14

What kingdom does these features contain : heterotrophic eukaryotes , cell wall of chitin, reproduce by spores (1)

Answer 14

fungi

Question 15

What kingdom does these features contain : Heterotrophic , multicellular eukaryotes , no cell wall , nervous coordination (1)

Answer 15

Animalia

Question 16

What kingdom does these features contain : eukaryotes , single celled, no tissue differentiation (1)

Answer 16

Protoctista

Question 17

What kingdom does these features contain : Unicellular , microscopic , no membrane bound organelles, cell wall not cellulose , cell wall made of murein (1)

Answer 17

Prokaryota

Question 18

What kingdom does these features contain : multicellular eukaryotes , photosynthetic , cellulose cell wall (1)

Answer 18

Plantae

Question 19

State what is meant by the term species (1)

Answer 19

a group of organisms that can interbreed to produce fertile offspring

Question 20

State one characteristic of fungi (1)

Answer 20

• reproduce by spores
• hyphae
  *Mycelium
  *chitin cell walls
  *heterotrophic
  *saprotrophic
  *eukaryotic

Question 21

State one characteristic of Protoctista (1)

Answer 21

*membrane bound organelles
*eukaryotic
*no tissue differentiation
*single celled organisms
*unicellular

Question 22

What are common structures but different functions (1)

Answer 22

Homologous

Question 23

What are common functions but different structures (1)

Answer 23

analogous

Question 24

Name the evolutionary change illustrate by Darwin’s finches (1)

Answer 24

Adaptive radiation

Question 25

Describe the process which results in the evolutionary change shown in Darwin finches (4)

Answer 25

* mutation occurs * leads to variation of beak shape * becomes adapted to eat particular food * have a selective advantage to a particular environment * more reproduce and pass on genes

Question 26

Human haemoglobin is a protein molecule containing 574 amino acids. The haemoglobin of a horse has 557 amino acids in common with humans and the haemoglobin of a gorilla has 572 amino acids in common with humans Explain the information indicating about the evolutionary relationship between three animal between three animal species (3)

Answer 26

* humans are more closley related to gorillas * more amino acids in common / gorilla has 572 in common with humans while horse has 557 / gorilla has 2 different from humans while horse has 17 different * share more common recent ancestor

Question 27

Name the technique used to compare the amino acid composition of haemoglobin in different animals (1)

Answer 27

* chromatography * electrophoresis

Question 28

How has this biochemical technique helped improve the classification of organisms (1)

Answer 28

* reduces mistakes made in classification due to convergent evolution

Question 29

State one feature of pygmy chimpanzees that places them into the phylum chordata (1)

Answer 29

they possess a backbone / internal skeleton / well developed CNS

Question 30

State one feature of pygmy chimpanzees that places them into the class mammalia (1)

Answer 30

fur / mammary glands / sweat glands / endothermic / internal gestation / double circulation

Question 31

Name statistical test which could be used to compare the biodiversity of the two sites (1)

Answer 31

Simpson' index

Question 32

The two sites samples showed significant variation in the distribution of phytoplankton . Suggest improvements to the sampling method in order to further investigate biodiversity along the stretch of the coastline (3)

Answer 32

* sample in more locations along the coastline * sample in more than once in a day / more frequently * use a larger net / increase the volume of water samples / increase sample size

Question 33

Describe the digestion of the yeast cell including the role of the golgi body (2)

Answer 33

* golgi body produces enzymes packages into lysosomes * lysosomes fuse with phagocytotic vesicle and release enzymes

Question 34

Describe the structure of a virus and explain why it is not considered to be a cell (2)

Answer 34

*molecule of nucleic acid surrounded by protein coat * acellular as has no membranes organelles / cell membrane / cytoplasm

Question 35

Giant panda and the red panada has a difference of 17 there are 3.95 x 10 ^-7 mutations per year when was the last time they shared a common ancestors

Answer 35

17/3.95x10^-7 = 4.3x10^-7 years

Question 36

Distinguish between analogous and homologous structures and why analogous features are not considered evidence of common ancestry (3)

Answer 36

* analogous structures are different structures to perform a similar function * homologous structure evolve from a common ancestor similar structure performing different function Analogous structures arise from convergent evolution

Question 37

Identify the domain the giant panda would belong Give a reason (2)

Answer 37

* Eukaryota * contains membrane bound organelles ? Dna bound in a nuclear envelope * 80 s ribosomes * multicellular