Biodiversity

Question 1

What is Biodiversity?

Answer 1

 variety in an ecosystem
 variety of habitats and variety of species

Question 2

What is Species Diversity?

Answer 2

 number of different species
 number of individuals for each species

Question 3

What is Genetic Diversity?

Answer 3

 variety of alleles in a species population
 the larger number of individuals in a species, the larger the genetic diversity

Question 4

Benefit of high species diversity?

Answer 4

 Stable ecosystem
 each species is less likely to become extinct (due to high genetic diversity)
 & if a species does become extinct it will not affect the food chain as there are other species available

Question 5

How to measure Species Diversity for an area?

Answer 5

 Species Diversity Index
 takes into account the number of different species and how many individuals there are for each species
 the larger the species diversity index, the larger the species diversity

Question 6

How does deforestation lower species diversity?

Answer 6

 (deforestation is the removal of trees for wood & space)
 decreases plant species diversity
 less variety of habitats
 less variety of food sources
 decreases animal species diversity

Question 7

How does agriculture/farming lower species diversity?

Answer 7

 deforestation to make space for farm
 only grow a few plants & keep a few animal species
 selectively breed plants & animals
 use pesticides to kill other species

Question 8

What is Classification?

Answer 8

placing organisms into groups

Question 9

What is Hierarchical Classification?

Answer 9

 large groups divided into smaller groups with no overlap
 domain, kingdom, phylum, class, order, family, genus, species

Question 10

What is Binomial Naming System?

Answer 10

 using Genus name and Species name to name organism
 Genus name first in capital, Species name second in lower case
 e.g. tiger = Felix tigris

Question 11

What is a Species?

Answer 11

a group of individuals with similar characteristics that can interbreed to produce fertile offspring

Question 12

Why are the offspring from 2 different species mating infertile?

Answer 12

 offspring will have a odd number of chromosomes
 therefore, cannot perform meiosis, cannot produce gametes
 example: horse + donkey = mule,
mule is infertile,
horse has 64 chromosomes/donkey has 62 chromosomes,
horse gamete has 32 chromosomes/donkey gamete has 31 chromosomes,
therefore, mule has 63 chromosomes

Question 13

What is Phylogenetic Classification?

Answer 13

based on evolutionary relationships – how closely related different species are and how recent a common ancestor they have

Question 14

3 ways of comparing relationship between different species?

Answer 14

• DNA Hybridisation
• Amino Acid sequence
• Protein Shape

Question 15

what is DNA Hybridisation?

Answer 15

comparing DNA base sequence

Question 16

AA Sequence?

Answer 16

comparing AA sequence for the same protein (e.g. haemoglobin in mammals)

Question 17

protein shape?

Answer 17

comparing shape of the same protein (e.g. albumin) using immunological technique

Question 18

What is Variation?

Answer 18

difference in characteristics between organisms

Question 18

What is Variation?

Answer 18

difference in characteristics between organisms

Question 19

Types of Variation?

Answer 19

intraspecific = differences between organisms of the same species
interspecific = differences between organisms of different species

Question 20

Causes of Intraspecific Variation?

Answer 20

Genetic Factors = same genes but different alleles (allele are different type/forms of genes)
Environmental Factors

Question 21

Causes of Interspecific Variation?

Answer 21

Genetic Factors = different genes and different alleles

Environmental Factors

Question 22

Types of Characteristics?

Answer 22

Discontinuous and Continuous

Question 23

Properties of Discontinuous Characteristics?

Answer 23

characteristics fall into certain groups with no overlap (e.g. blood group) – determined by genetics only (a single gene)

Question 24

Properties of Continuous Characteristics?

Answer 24

characteristics show a range (e.g. height) – determined by genetics (a few genes, polygenes) and environment

Question 25

What is Genetic Diversity?

Answer 25

genetic variation, the variety of alleles within a population of a species

Question 26

Benefit of high genetic diversity?

Answer 26

species able to adapt with changes in the environment e.g. if a new disease arises, some individuals will have characteristics to survive, and will reproduce passing on their alleles, so the species does not become extinct

Question 27

What can lower genetic diversity?

Answer 27

small population size (e.g. founder effect – where the numbers start low, or genetic bottleneck – where the numbers decrease)

Question 28

What is natural selection and adaptation?

Answer 28

 variation in population of species (genetic diversity/genetic variation/variety in gene pool)  new alleles arise by random mutation  environment applies a selection pressure on the population  those with favourable characteristics/favourable alleles/selection advantage/better adapted survive, the others die [natural selection]  the ones that survive will reproduce, passing on their favourable alleles  if this happens for many generations, then that characteristic will become most common – the allele will become more frequent [adaptation]

Question 29

What are the 2 types of selection?

Answer 29

stabilising and directional

Question 30

What is stabilising selection?

Answer 30

 when the environment favours those with the most common characteristic – those on the extreme dies out  the common characteristic increases in proportion  the range (standard deviation) will reduce

Question 31

What is directional selection?

Answer 31

 when the environment favours those individuals with characteristics on one of the extremes  over time this will become the most common characteristic  normal distribution will shift to that extreme

Question 32

What is directional selection?

Answer 32

 when the environment favours those individuals with characteristics on one of the extremes  over time this will become the most common characteristic  normal distribution will shift to that extreme

Question 33

How to carry out DNA Hybridisation?

Answer 33

- take DNA from 2 species to be compared - radioactively label one of the DNA - heat both sets so double strand separates - cool so single strands join together - look for Hybrid DNA (one strand from species A, one strand from species B) - identify Hybrid DNA by 50% radioactivity - heat Hybrid DNA to measure similarity

Question 34

results of DNA hybridisation?

Answer 34

-higher temperature required -more hydrogen bonds present -more complementary base pairing -more similar the base sequence -more similar the species -more closely related -more recent a common ancestor

Question 35

results of AA sequencing?

Answer 35

-more similar the AA sequence -more similar the DNA base sequence -more similar the species -more closely related -more recent a common ancestor

Question 36

How to carry out protein shape?

Answer 36

- comparing species A and species B - take albumin from species A - place in a blood of rabbit - rabbit will make antibodies against albumin of species A - takes these antibodies and place in blood from species B - if the albumin in species B has a similar shape to species A, the antibodies will bind to form antigen-antibody complexes, this will then form a precipitate

Question 37

results of protein shape?

Answer 37

-more precipitate -more complexes -more similar shape -more similar the species -more closely related -more recent common ancestor

Question 38

why is comparing base sequence better than comparing amino acid sequence?

Answer 38

- DNA sequence provides information on INTRONS - triplet code is DEGENERATE

Question 39

how do courtship behaviours help an organism reproduce?

Answer 39

- enable members to identify their own species - use similarities in physical characteristics and behaviours - prevents cross breeding and infertile offspring being produced - identifying a mate that is capable of breeding - both partners need to be sexually mature, fertile and receptive to mating - forming pair bonds - lead to successful breeding - successful raising of the offspring - synchronising mating seasons - ensure maximum chance of fertilisation - males show courtship behaviour to determine whether the female is receptive (fertile state) - if female responds with correct courtship behaviour then mating will take place

Question 40

equation for species diversity index?

Answer 40

d= N(N-1)/ Σn(n-1) N= total number of organisms of all species n= total number of organisms of each species

Question 41

what is the difference between index of diversity and species richness?

Answer 41

- species richness only takes into account the number of different species in a particular area - index of diversity takes into account the number of species in a community and the number of individuals in each species

Question 42

How to calculate possible number of different combination of chromosomes following meiosis, without crossing over?

Answer 42

2^n N= number of homologous pairs