Topic 4

Question 1

What is species richness?

Answer 1

The number of different species in a habitat.

Question 2

What is genetic diversity?

Answer 2

A measure of the genetic variation found in a particular species/ the number of alleles in a gene pool.

Question 3

What is endemism?

Answer 3

A species being unique to a particular geographic loaction and not found anywhere else.

Question 4

What is a niche?

Answer 4

A species role within within the community.

Question 5

What is the process of natural selection?

Answer 5

• A variety of phenotypes exist within a population due to mutation.
• An environmental change occurs and as a result the sleection pressure changes. (competition e.g food, shelter, mate)
• Some individuals possess advantageous alleles which give them a selective advantage.
• Advantageous alleles are then passsed on to the offsprings
  Over time the frequency of alleeles changes.

Question 6

What are the condiitons when using Hardy Weinberg?

Answer 6

• No mutations
• Random mating
• Large population
• Isolated population
• No selection pressure

Question 7

What is classification?

Answer 7

Organising the variety of life based on relationships between organisms using differences and similarities in genotypes and phenotypes

Question 8

What is the order in the binomial system?
King Philip came over for good spagetti

Answer 8

Kingdom
Phylum
Class
Order
Family
Genus
Species

Question 9

What is molecular phylogeny?

Answer 9

The analysis of molecular differences in different organisms to determine the extent of their evolutionary relationship

Question 10

What are the three domains?

Answer 10

Bacteria, Archaea, Eukaryota

Question 11

What is the formula for heterozygosity index?

Answer 11

H= number of heterozygotes/ number of individuals in the population

Question 12

What is the formula for index of diversity?

Answer 12

D=N(N-1)/En(n-1)

Question 13

What are anatomical, behavioural and physiological adaptations?

Answer 13

anatomical - physical adaptations.
physiological - proccess that increase the organisms chance of survival e.g produces venom,

Question 14

What are sclerenchyma fibres?

Answer 14

Provide structural support. They are short structures made of dead cells with a hollow lumen and end walls. They are also thickened with lignin.

Question 15

Why are plant fibres useful?

Answer 15

• sustainable and renewable
• biodegradable
• very strong (can make ropes and fabric)
• cheaper
• starch can be used to make bioplastics and bioethanol which are fuels.

Question 16

What is William Withering’s digitalis soup?

Answer 16

Isolated teh active ingredient form fox glove and tested different dosages of people.

Question 17

What is phase 1 of drug testing?

Answer 17

Different dosages of the drug is test on a small group of people to see if it is safe to use.

Question 18

What is phase 2 of drug testing?

Answer 18

Drug is tested on a group of pateints with the condition to see if the drug has any effect.

Question 19

What is phase 3 of drug testing?

Answer 19

The drug is tested on a big group of pateints to assess the effectivness. Double blind trial and a placebo is given.

Question 20

What is the middle lamella?

Answer 20

Outer layer of cell wall which holds adjacent cells together as well as providing support and protection.

Question 21

What is the structure and function of chloroplasts?

Answer 21

Cntan thylakloid membranes which are stacked into grana. These contain chloropyll. Surrounded by stroma, a liquid which contains photosynthetic enzymes.

Question 22

Describe the structure and function of amyloplasts.

Answer 22

Produces and stores starch composed of amylose and amylopectin. Surrounded by a double memebrane.

Question 23

Describe the structure and function of the plasmodesmata.

Answer 23

Extensions of the cytoplasm that connect two neighbouring cells together, allowing transport of substances between them.

Question 24

Describe the structure and functions of pits

Answer 24

Thin sections of the cell wall that allow easy diffusion, enabling substances to be transferred between cells.

Question 25

What is the structure of starch?

Answer 25

Amylose - coiled, unbranched Amylopectin - highly branched 1-4 and 1-6 glycosidic bonds

Question 26

Relate the structure of xylem and sclerenchyma fibres to their function.

Answer 26

- cellulose microfibrils form net like arrangement in the cell walls o fthe fibres - Secondary thickening further strengthens the fibres by adding lignin -

Question 27

What are the differences between phloem, xylem and sclerenchyma fibres?

Answer 27

xylem = made up of dead tissue with open ends, transport water and minerals, structual support Phloem = made of living cells, translocate organic substances form leaves to storage. Sclerenchyma = mad eup of dead tissue with closed ends. structural support.

Question 28

What is the importance of water to plants?

Answer 28

- required for photosynthesis - maintain rigity of cells - Transport of substances - Thermoregulation

Question 29

Define speciation

Answer 29

Where a population is split and isolated, there are different selective pressures on the two groups. If the genetic makeup changes to the extent thatthe two groups can no longer interbreed, they are two new/separate species.

Question 30

Define biodiversity

Answer 30

The variety of living organisms. It can be measured by the genetic diversity within a species or the number of species within a habitat.

Question 31

Define endemism

Answer 31

When a species is found in only one georaphical location and is not found anywhere else.

Question 32

How can we compare the biodiversity of different habitats?

Answer 32

Index of diveristy formula

Question 33

Why does natural selection occur?

Answer 33

1) Competition 2) Disease 3) Predation

Question 34

What is the consequence of reproductive isolation?

Answer 34

Speciation

Question 35

Explain how using plant based products can improve sustainability.

Answer 35

sustainability = using resources in a way that also maintains them for future generations -Plant fibres- used in fabrics are biodegradable and cheap. - Starch, used in biofuel is extracted from crops which can be regrown.

Question 36

Define conservation.

Answer 36

The protection and managemnet of species and habitats, in order to maintain biodiversity

Question 37

What are some methods used in conservation of endangered species?

Answer 37

Ex-situ: - Captive breeding followed by reintroduction - Seed banks In- situ: - Scientific research - Education

Question 38

What is an adavantage and disadvantage of ex-situ?

Answer 38

+ require little space, eliminates predators and poachers - expensive, disease spreads quickly.

Question 39

What are the advanatges and disadvantges of in- situ?

Answer 39

+ protects more than one species, cheap, - Hard to enforce legislation

Question 40

Name three inorganic ions and explain why they are important to plants?

Answer 40

Magnesium ions: production of chlorophyll and activation of enzymes Calcium: forms calcium pectate for cell wall, used in growth. Nitrate: supply nitrogen for production of DNA, proteins and chloropyll.

Question 41

Explain why water is important for plants?

Answer 41

- Thermoregulation - Photosynthesis - maintains rigidity of cellls - transport of subtsances