Biology Topic-4

Question 1

Define biodiversity

Answer 1

Variety of living organisms in an area

Question 2

Define species diversity

Answer 2

Number of different species

Question 3

Define genetic diversity

Answer 3

Variation of alleles within a species

Question 4

Define Endemism

Answer 4

Species unique to a single place

Question 5

What does maintaining genetic diversity mean?

Answer 5

Ensuring a wide gene pool.
More likely for the species to survive due to the range of genes
Species likely to better evolve

Question 6

What does genetic drift mean?

Answer 6

Random changes in the frequency of alleles from generation to generation
Very noticeable in small populations
Aim to reduce this by using healthy animals in breeding

Question 7

What is inbreeding depression?

Answer 7

New alleles less likely to join the gene pool if breeding is done with related individuals
Homozygous tend to rise heterozygous decrease
Many recessive alleles can be harmful
Offspring can be smaller, unhealthy and don’t live as long

Question 8

Define allele

Answer 8

A form/ type of a gene

Question 9

Define gene

Answer 9

A sequence of bases coding for a protein

Question 10

Define species

Answer 10

A group of organism that can breed and produce fertile offspring

Question 11

Define species richness

Answer 11

Number of different species in an area

Question 12

Define species evenness

Answer 12

How close in number each species is in an environment

Question 13

How to calculate biodiversity within a species

Answer 13

Heterozygosity index (no of heterozygotes/ population)

Question 14

How to calculate biodiversity in a habitat

Answer 14

Species richness (no of different species)

Question 15

How to calculate biodiversity between habitats

Answer 15

Biodiversity index N(N-1)/ E n(n-1)

Question 16

What are the hardy weinberg equations?

Answer 16

p+q=1
p^2 +2pq+ q^2= 1

p is dominant
q is recessive

Question 17

Define niche

Answer 17

The role that an organism plays in an environment and how it affects its survival

Question 18

Name the 3 different adaptations

Answer 18

Physiological - process inside body e.g hibernation
Behavioural- actions e.g playing dead
Anatomical- structural features e.g streamlined shape

Question 19

Define speciation and the cause

Answer 19

Formation of new species .
Reproductive isolation- individuals isolated for a long time and mutate until are recognised as different species
e.g on different islands or blocked by mountains

Question 20

Name the 2 ways of classification

Answer 20

Hierarchical system

Phylogenetic system

Question 21

Describe how organism are classed in the phylogenetic system

Answer 21

Based on evolutionary origins. figured by analysing DNA

Hierarchy means smaller groups put into larger groups

Question 22

Why are Nitrates needed? What would deficiency look like?

Answer 22

Needed for amino acids
Needed for growth
Deficiency - yellow leaves, stunted growth

Question 23

Why is Magnesium needed? What would deficiency look like?

Answer 23

Needed for chlorophyll formation
Needed in photosynthesis
Deficiency - yellow leaves + red tinges, slow growth

Question 24

Why is Calcium needed? What would deficiency look like?

Answer 24

Needed for cell wall formation
Needed for structure
Deficiency - stunted growth, no new cells

Question 25

Devise method of looking at plant stems

Answer 25

Cut as thinly as possible
Toluidine blue stain
Cover slip
Start of with lowest magnification

Question 26

What makes plants strong

Answer 26

Microfibril arrangement
Lignin
Secondary cell wall

Question 27

Positives of using plant fibres in products

Answer 27

Sustainable
Less fossil fuel used
Biodegradable
Easier to extract and process than oil

Question 28

Use of starch in sustainability

Answer 28

Bio plastics

Bio ethanol

Question 29

Advantages and disadvantages of seed banks

Answer 29

A- cheaper than full plants, large numbers stored, less labour, safe from damage
D- expensive to test viability, difficuly to collect

Question 30

What conditions are necessary for the Hardy Weinberg equations to be true?

Answer 30

No natural selection
No migration
No mutations
A large population