1: Problems of Life, Animal Classifications & Relationships

Question 1

What defines an animal?

Answer 1

multicellular
motile (at least in one life stage)
heterotrophic
arise from embryos
produce gametes

Question 2

All animals must do this to survive

Answer 2

get food
get oxygen
keep water balance (to control internal solutes)
removes metabolic wastes
reproduce

Question 3

How do they solve the problems to survive

Answer 3

Solutions arise from environment, lifestyle, and size via the process of evolution

Question 4

Humidity (life challenges)

1: Aquatic
2: Terrestrial

Answer 4

1: High = gills, dissolving excreta
2: Low = internal breathing organs, solid or liquid excreta

Question 5

Density (life challenges)

1: Aquatic
2: Terrestrial

Answer 5

1: High = less physical support needed
2: Low = stronger physical support needed

Question 6

Temperature Fluctuations (life challenges)

1: Aquatic
2: Terrestrial

Answer 6

Low = water buffers extremes of temperature
High = spp need ability to manage body temperature

Question 7

Oxygen Solubility (life challenges)

1: Aquatic
2: Terrestrial

Answer 7

Low = 6-8 ml/L at best
High = 210 ml/L of air

Question 8

Viscosity (life challenges)

1: Aquatic
2: Terrestrial

Answer 8

!: High high friction against movement but, lower fall risk

2: Low = less friction against movement, but higher fall risk

Question 9

Light (life challenges)

1: Aquatic
2: Terrestrial

Answer 9

1: Low at depth - animals may be far from primary producers
2: High unless underground - animals close to plants

Question 10

Nutrients (life challenges)

1: Aquatic
2: Terrestrial

Answer 10

1: Easily absorbed form dissolved sources in water
2: Not available from air. Need to find other ways to obtain (especially in water)

Question 11

Define sessile

Answer 11

fixed in one place; immobile.

Question 12

Locomotion

1: Bilateral symmetry animals
2: Radial symmetry animals

Answer 12

free-moving

sessile

Question 13

Radial Symmetry

Answer 13

a type of structure of an organism or part of an organism in which a vertical cut through the axis in any of two or more planes produces two halves that are mirror images of each other

Question 14

Bilateral Symmetry

Answer 14

symmetry in which similar anatomical parts are arranged on opposite sides of a median axis so that one and only one plane can divide the individual into essentially identical halves

Question 15

SA:V ratio falls as length increases

1: Aquatic environments
2: Terrestrial environments

Answer 15

1: where diffusion is occurring, so SA maximized
2: where animals are trying to prevent water loss they try to minimize SA to volume ratio

Question 16

Small animals (shape)

Answer 16

Use diffusion for gas exchange, excretion and transportation

Question 17

Large animals (Shape)

Answer 17

Have coeloms and blood vascular systems and fold and coil their viscera to fit compactly into the body

Question 18

zygote define

Answer 18

a diploid cell resulting from the fusion of two haploid gametes; a fertilized ovum

Question 19

Blastula define

Answer 19

an animal embryo at the early stage of development when it is a hollow ball of cells

Question 20

Grastrula

Answer 20

an embryo at the stage following the blastula, when it is a hollow cup-shaped structure having three layers of cells.
Radial symmetry animals.

Question 21

Complete gut forms

Answer 21

Pseudocoelomate
Acoelomate
Coelomate

Question 22

Pseudocoelomate define

Answer 22

an organism with body cavity that is not derived from the mesoderm, as in a true coelom, or body cavity.
eg. invertebrates (nematodes and rotifers)

Question 23

Acoelomate

Answer 23

an animal that has no internal, fluid-filled body cavity separating its body wall from its digestive tract.

• packed solid with cells
  eg. group comprising the flatworms and nemerteans characterized by bilateral symmetry and a digestive cavity that is the only internal cavity

Question 24

Coelomate

Answer 24

have a body cavity called a coelom with a complete lining called peritoneum derived from mesoderm (one of the three primary tissue layers).
eg. metazoans

Question 25

metazoans

Answer 25

animals that develop from an embryo with three tissue layers

Question 26

three tissue layers

Answer 26

ectoderm, mesoderm, and endoderm

Question 27

Diploblastic define

Answer 27

animals that have two layers of cells (ectoderm and endoderm) in the embryo which give rise to all organs
acoelomate eg. cnidarian

Question 28

Triploblastic

Answer 28

animals that have a third cell layer in the embryo mesoderm
acoelomate
eg platyhelminthes
coelomate
eg. echinoderm, mollusc, chordate (larger animals)

Question 29

Species generally defined as

Answer 29

having the capacity to reproduce successfully to produce fertile offspring

Question 30

Taxonomy hierarchy classification system

Answer 30

Domain                         Did
Kingdom                       King
Phylum                          Phillip
Class                             Come
Order                            Over
Family                           For
Genus                          Good
Species                        Soup

Question 31

Evolution

Answer 31

Processes by which new types of life occur on earth
works via inheritance and death
if they die then genes do not pass on.
only events before or during reproduction that are important

Question 32

Systematic define

Answer 32

Study of biological diversity and its classification,

produces classifications that best express the relatedness of organisms

Question 33

what studies are combined into systematics

Answer 33

morphology, embryology and genetics

Question 34

Cladistics

Answer 34

a method of classification of animals that aims to identify and take account of only those shared characteristics which can be deduced to have originated in the common ancestor of a group of species during evolution, not those arising by convergence

Question 35

Convergence

Answer 35

the tendency of unrelated animals to evolve superficially similar characteristics under similar environmental conditions

Question 36

phylogeny

Answer 36

history of the evolution of a species or group, especially in reference to lines of descent and relationships among broad groups of organisms.

Question 37

Homologous define

Answer 37

similar in position, structure, and evolutionary origin but not necessarily in function
characters indicating common ancestry must be homologous

Question 38

Analogous

Question 39

Analogous

Answer 39

performing a similar function but having a different evolutionary origin, such as the wings of insects and birds

Question 40

What does molecular genetics use

What can it tell us

Answer 40

Hox genes, rRNA, mtDNA and other sequences.

how many steps separate species

Question 41

What cant molecular data do

Answer 41

resolve the precise sequence of steps
tell us the selection pressures
predict what unfossilised ancestors looked like
resolve the order of divergence in rapidly diversifying species

Question 42

Hox (or homeotic) genes

what do they do

Answer 42

control the embryonic body along the anterior-posterior axis

activate or repress genes

Question 43

rRNA

Answer 43

18s rRNA is structural for eukaryotic ribosomes, the sequences have slow evolutionary rates suitable for phylogenetic analysis

Question 44

mtDNA

Answer 44

Originates from mitochondrion, in most species inherited solely from the mother (only in egg). Hasnt changed much through history so useful in phylogenetics and population differentiation.