Form and Function

Question 1

Main features of body plans in invertebrate phyla

Answer 1

• skeleton
• symmetry
• segmentation
• body cavities

Question 2

Skeletons can be?

Answer 2

Hydrostatic, endoskeleton and exoskeleton

Question 3

Symmetry can be?

Answer 3

None, radial, bilateral, pentaradial

Question 4

segmentation can be?

Answer 4

none, yes, yes but modified

Question 5

body cavities can be?

Answer 5

none, yes, yes but different

Question 6

what is an explanation for the trade off theory

Answer 6

an organism can’t be good at everything all the time

Question 7

In human biology and vertebrates, what can help to determine speed, strength and efficiency?

Answer 7

mass and cross-sections and corss-sectional area

Question 8

Physical constraints involved with burrowing and tunnelling

Answer 8

cross-sectional area determines resistance (larger = more resistance)
pushing strength increased by using lots of legs or big muscles of the body (peristalsis)

Question 9

what are scaling laws?

Answer 9

how biological processes are affected by mass

Question 10

is metabolic rate proportional to mass?

Answer 10

yes - wide spread and not always understood relationships

Question 11

Is it possible to change the size of something?

Answer 11

not without allometric problems
e.g humans wouldn’t be able to stay warm, process food, break legs

Question 12

what is allometry?

Answer 12

idea that different processes scale at different rates

Question 13

Why is there so much functional diversity?

Answer 13

need for oxygen increases with your length cubed but external surface area available to absorb oxygen only increases with length squared

Question 14

Assuming a constant shape in mass/surface area ratios, volume is…

Answer 14

proportional to length cubed

Question 15

Re = ?

Answer 15

Reynolds number

Question 16

what is the Reynolds number?

Answer 16

reflects ratio of inertial to viscous forces in fluid

Question 17

What happens when Re is high?

Answer 17

See lots of turbulent flow

Question 18

What happens when Re is low?

Answer 18

fluid motion is smooth or laminar

Question 19

Formula to calculate Re?

Answer 19

Re = Length X relative fluid velocity / viscosity

Question 20

Large swimming animals in relation to Re

Answer 20

have to be streamlined to minimise turbulence
Re number will be very high so turbulence usually a significant problem

Question 21

what is catapult jumping?

Answer 21

storing energy and releasing it suddenly

Question 22

equation for kinetic energy?

Answer 22

kinetic energy = 1/2mv squared

Question 23

why do insects have 6 legs?

Answer 23

always 3 points of contact
climbing
stick out in front to detect movement in front

Question 24

what is a phylum?

Answer 24

taxonomic rank lower then kingdom and higher than class

Question 25

what is taxonomy?

Answer 25

classification of organisms

Question 26

phylogenetics

Answer 26

reconstruction of evolutionary events

Question 27

what does binomial name mean?

Answer 27

genua + species

Question 28

what is cladistics?

Answer 28

phylogenetics organised based on traits

Question 29

what is a clade?

Answer 29

ancestral species and all it’s descendants

Question 30

what are phylogenies?

Answer 30

product of phylogenetics
made up of branches and nodes

Question 31

what is a node?

Answer 31

shows divergence of evolutionary lineages

Question 32

what is a polytomy?

Answer 32

multiple clades or lineages diverge from a single node

Question 33

what is a monophyletic group?

Answer 33

ancestral species and all descendants

Question 34

what is a paraphyletic group?

Answer 34

ancestral species and some of it’s descendants

Question 35

what is a polyphyletic group?

Answer 35

taxa with multiple different ancestors

Question 36

what is convergent evolution?

Answer 36

process where by a common solution to a physical problem can produce similar morphological traits

Question 37

what are synapomorphies?

Answer 37

each clades defined by unique shared derived traits

Question 38

first step in cladistics and putting species into clades

Answer 38

separate homologous features from the analogous ones

Question 39

taxon is only equivalent to a clade if…?

Answer 39

it is monophyletic

Question 40

what is an outgroup?

Answer 40

species diverged before the lineage that contains all species you’re interested in

Question 41

what are genes made up of?

Answer 41

1000’s of nucleotides, each representing an inherited character

Question 42

in tree of life, when can branches indicate degree of evolutionary change

Answer 42

with molecular data

Question 43

what is a molecular clock?

Answer 43

means of dating the divergence of organisms by looking at the changes in the structure of basic proteins or DNA

Question 44

assumptions made for molecular clocks?

Answer 44

mutations accumulate randomly
number of changes is proportional to time since divergence from common ancestor

Question 45

how do we calibrate the molecular clock?

Answer 45

measuring the difference between the genes in different groups that diverged at a known point

Question 46

what can we do if the clock is reliable?

Answer 46

we can infer divergence time of clades with known genetic differences

Question 47

what is genetic drift?

Answer 47

random accumulations of mutations with little effect on fitness

Question 48

problems with molecular clocks?

Answer 48

only tick regularly for mutations that are ‘neutral’
DNA regions are under strong natural selection are not neutral and not good for phylogenies