ADAPTIONS

Question 1

What is an adaption? (1)

Answer 1

Adaption is the process by which an organism becomes fitted to its environment.

Question 2

What are the types of adaption? (3)

Answer 2

-physiological
-anatomical
-behavioural

Question 3

What is a physiological adaption? (1)

Answer 3

Are adaptions which are the results of changes to the metabolism of the organism.

Question 4

what is a anatomical adaption? (1)

Answer 4

Changes to the actual structure of the organism.

Question 5

Give some examples of physiological adaptions. (2)

Answer 5

the production of different algal pigments which flourish at different zones of the shoreline community.

Question 6

what is chemosynthesis? (1)

Answer 6

a method used by some microorganisms to release energy from inorganic molecules, typically molecules such as ammonia or metal sulphides are oxidised and the energy released used to build organic molecules.

Question 7

give some examples of anatomical adaptions. (1)

Answer 7

body structures adapted to regulate heat loss in various mammals, mammals are described as endotherms since their body heat comes from metabolic reactions

Question 8

what is a ectotherm? (1)

Answer 8

animals that are unable to regulate their body temperature effectively by internal means, in order to survive in a variety of niches they must adapt behaviourally to avoid large fluctuations in body temperature.

Question 9

what is evolution? (1)

Answer 9

the development of new types of living organism from pre-existing types by the accumulation of genetic differences over long periods of time.

Question 10

what are the arguments presented by Darwin for natural selection? (1)
POINT 1

Answer 10

-Organisms produce many more offspring than survive to be mature individuals

Question 11

what are the arguments presented by Darwin for natural selection? (1)
POINT 2

Answer 11

the individuals in a species are not all identical

Question 12

what are the arguments presented by Darwin for natural selection? (1)
POINT 3

Answer 12

natural selection results in offspring with favourable characteristics

Question 13

What evidence supports Darwin’s first point on natural selection?

Answer 13

in a stable population, a breeding pair gives rise to a single breeding pair of offspring, all of their other offspring are casualties of the ‘struggle’, many organisms die before they can reproduce.

Question 14

how is population size controlled? (1)

Answer 14

population size is naturally limited by restraints we call ‘environmental factors’ which include space, light and availability of food, the competition for these resources is what maintains a stable population.

Question 15

What evidence supports Darwin’s second point on natural selection? (3)

Answer 15

genetic variation arises from;
-random assortment
-crossing over
-random fusion of gametes

Question 16

how does random assortment cause genetic variation? (1)

Answer 16

random assortment of maternal and paternal chromosomes in meiosis this occurs in the process of gamete formation.

Question 17

how does crossing over cause genetic variation? (1)

Answer 17

crossing over of segments of individual maternal and paternal homologous chromosomes that results in new combinations of genes on the chromosomes of the haploid gametes produced by meiosis.

Question 18

how does random fusion of gametes cause genetic variation? (1)

Answer 18

the random fusion of paternal and maternal gametes in sexual reproduction,

Question 19

What evidence supports Darwin’s third point on natural selection? (2)

Answer 19

when genetic variation arises in organisms;
-the favourable characteristics are expressed in the phenotype of some of the offspring
-these offspring may be better able to survive and reproduce in particular environments.

Question 20

what are the variation in fossils? (4)

Answer 20

-petrified remains
-moulds
-traces
-preserved, intact whole organisms

Question 21

what are petrified remains? (1)

Answer 21

organic matter of the dead organisms is replaced by mineral ions

Question 22

what are moulds, in terms of fossils? (1)

Answer 22

the organic matters decays but the vacated space becomes a mould

Question 23

what are traces in terms of fossils? (1)

Answer 23

an impression of a form such as a leaf or footprint.

Question 24

what is meant by preserved, intact whole organisms? (1)

Answer 24

trapped in amber, ice or in anaerobic, acidic peat.

Question 25

what is proteomics? (1)

Answer 25

the study of the proteins coded for by specific genes found in the human genome.

Question 26

what is serum? (1)

Answer 26

serum is the liquid produced from blood when blood cells and fibrinogen have been removed.

Question 27

how can immunological studies assist evolution? (1)

Answer 27

the immune reaction provides a mechanism of detecting differences in specific proteins and therefore (indirectly) their relatedness, protein molecules present in serum act as antigens when serum is injected into animals with an immune system that lacks these particular proteins, the injection triggers the production of antibodies against the injected ‘foreign’ proteins. Then, fresh serum is produced from the treated rabbits blood (it now contains antibodies against human blood)

Question 28

what is DNA hybridisation? (1)

Answer 28

involves matching DNA from different species to test the degree of base pairing that occurs.

Question 29

what does DNA hybridisation tell us? (1)

Answer 29

this tells us the approximate degree of divergence between closely related groups, this data can be correlated with the data on the estimated number of years thy shared a common ancestor.

Question 30

what is known as the molecular clock? (1)

Answer 30

measurement of changes in DNA from selected species has a potential as a molecular clock.

Question 31

what is the difference between nucleic DNA and mitochondrial DNA? (2)

Answer 31

-the nucleus contains about 99% of DNA
-the mitochondria contains about 1%

Question 32

what is the difference between nucleic DNA and mitochondrial DNA? (2)

Answer 32

Mutations occur at a very slow, steady rate in all DNA but chromosomal DNA has with it enzymes hat may repair changes in some cases, these enzymes are absent in mitochondrial DNA. This means that mitochondrial DNA changes 5-10 times faster than nucleic DNA.