Adaptation

Question 1

What is the process of Evolution or Adaptation?

Answer 1

Over time natural selection produces genes that increase fitness in particular environments. These genes then produce phenotypes that have functional roles.

Question 2

What is the name of the catapult mechanism in a jumping flea beetle?

Answer 2

Metafemoral spring

Question 3

Why do insects have six legs?

Answer 3

• Stability

- Points of contact in climbing

Question 4

What is a true tissue?

Answer 4

A group of specialized cells that act as a functional unit and are isolated from other groups of cells by membranous layers

Question 5

Name the 3 germ layers in a cell

Answer 5

Ectoderm - surface of embryo/outer animal layer
Endoderm - cell lines that develop in digestive tract
Mesoderm - between ectoderm and endoderm

Question 6

All bilaterally symmetrical animals have…

Answer 6

A third germ layer - mesoderm

Question 7

The body of a sponge consists of two layers of cells separated by a gelatinous region called….

Answer 7

The mesohyl - a gelatinous matrix

Question 8

What is the epidermis of a sponge called?

Answer 8

Pinacoderm

Question 9

How does water enter a sponge?

Answer 9

Via pores into a cavity called a spongocoel

Question 10

What is a choanocyte?

Answer 10

Specialized cells that have a single flagellum surrounded by a net-like collar of microvilli

Question 11

What is the function of Amoebocytes in the Porifera?

Answer 11

Amoebocytes manufacture tough skeletal fibres within the mesohyl (internal bit) which is equivalent to a endoskeleton

Question 12

Surface area must keep pace with what?

Answer 12

Volume

Question 13

What is the Linnaean system?

Answer 13

Taxonomic hierarchy consisting of Kingdom, Phylum, Class, Order, Family, Genus and Species.

Question 14

What is the main purpose of phylogenetics?

Answer 14

To make hypotheses about evolutionary relationships

Question 15

A widely used methodology to construct phylogeny is called…

Answer 15

Cladistics

Question 16

What is the aim of the cladistics methodology?

Answer 16

The objective is to place species into groups called clades which includes an ancestral species and all of its descendants.

Question 17

How do we link the taxonic hierarchy with the evolution of animal life?

Answer 17

The evolutionary history of a group of organisms can be represented in a branching diagram made up of Branches and Nodes

The branching patterns often match how taxonomists have classified groups of organisms nested within more inclusive groups.

Question 18

What does the term polytomy mean?

Answer 18

More than two lineages diverge from a single node in the phylogenetic tree

Question 19

What does sister taxa mean and provide an example?

Answer 19

Species share an immediate common ancestor

i.e. cubozoa and syphozoa (box and sea jellies)

Question 20

A group is monophyletic if…

Answer 20

The clade includes the ancestral species and all of its descendants

Question 21

A group is paraphyletic if…

Answer 21

The clade includes the ancestral species and some but not all of its descendants

Question 22

A group is polyphyletic if…

Answer 22

The clade includes taxa with different ancestors

Question 23

Similar features that arise due to shared ancestry are called…

Answer 23

Homologous structures

Question 24

What is meant by the term Convergent Evolution?

Answer 24

The process whereby distantly related organisms independently evolve similar traits to adapt to similar necessities. Appear similar but internal anatomy, physiology & reproductive systems are different

This is known as Analogous Similarities

Question 25

What are the closest living relative of animals (common ancestor)?

Answer 25

Suspension feeders known as choanoflagellates

Question 26

Why are choanoflagellates not animals?

Answer 26

They are unicellular - don’t have tissues that arise from embryonic layers

Question 27

Sequence of branching in a phylogenetic tress does NOT indicate what?

Answer 27

Age of species

Question 28

With the exception of sponges (and a few others) all animals come under the clade Eumetazoa . What are the characteristics of this clade?

Answer 28

They have true tissues organized into germ layers, the presence of neurons, and an embryo that goes through a gastrula stage.

Question 29

Name three characteristics of Cnidaria

Answer 29

- Diploblastic (two germ layers) - Radial symmetry - True tissues

Question 30

In Cnidaria the ectoderm and endoderm are separated by what?

Answer 30

Mesoglea - jelly like matrix

Question 31

What are the two types of body plan in the Cnidaria?

Answer 31

Medusa or polyp

Question 32

What are the 3 body layers of Cnidaria?

Answer 32

Epidermis, Mesoglea, Gastrodermis.

Question 33

What is the function of the gastrovascular cavity in Cnidaria?

Answer 33

Acts as a hyrdostatic skeleton (pressure is applied by fluid pressure) against which contractile cells can work

Question 34

What is the function of the nerve net?

Answer 34

Coordinates movement as Cnidaria do not have a brain

Question 35

In Cnidaria, enzymes are secreted into the cavity, breaking down the prey into a nutrient rich-broth. Cells lining the cavity then absorb the nutrients and undigested parts are expelled through the mouth/anus. What is the process called?

Answer 35

Extracellular digestion

Question 36

What are Cnidocyte cells?

Answer 36

Explosive cells containing one giant secretory organelle called a cnidocyst that can deliver a sting to other organisms

Question 37

What is the name of Cnidaria that have specialised spirocysts to capture prey?

Answer 37

Nematocysts

Question 38

What are the four major clades of the Cnidaria?

Answer 38

Hydrozoa - hydras Scyphozoa - true jellies Cubozoa - box jellies Anthozoa - corals and anemones

Question 39

What is a special feature of the Anthozoa (sea anemones, corals)?

Answer 39

They have a symbiosis with zooxanthellae which occurs in the gastrodermal cells. This can make them appear green as the zooxanthellae have chloroplasts

Question 40

What makes the Ctenophora (comb jellies) different from the Cnidaria?

Answer 40

Epidermis of the tentacles have peculiar adhesive cells called colloblasts.

Question 41

Similar features due to shared ancestry are called?

Answer 41

Homologous structures or "synapomorphies"

Question 42

How do biologist estimate when the ancestors of an organism live?

Answer 42

Molecular clocks which are a means of dating the divergence of organisms by looking at the changes in the structures of basic proteins or DNA

Question 43

What is the different between protostomes and deuterostomes?

Answer 43

Prostostomes - Mouth formed first in blastula | Deuterostomes - Anus formed first in blastula

Question 44

What are the characteristics of the Bilateria?

Answer 44

Have bilateral symmetry and tripoblastic development - 3 germ layers, endoderm, mesoderm, ectoderm and most have digestive tract with openings (mouth and anus) and coelom

Question 45

What are the 3 major clades of bilaterally symmetrical animals?

Answer 45

Deuterostomia, Lophotrochozoa; Ecdysozoa.

Question 46

How was the clade Lophotrochozoa identified?

Answer 46

By molecular data (DNA)

Question 47

What are the features of a Lophophore?

Answer 47

- Crown of ciliated tentacles | - Present in some members

Question 48

What are the features of trochophore larva?

Answer 48

- Shaped like a spinning top - Small and translucent - Prominent circlet of cilia

Question 49

What do nematodes possess?

Answer 49

Psuedocoeloms

Question 50

Flatworms are known as acoelomates because they lack what?

Answer 50

Body cavity

Question 51

In which two ways do Platyhelminthes reproduce?

Answer 51

- By fission (asexually) | - Sexually

Question 52

What is a main characteristic of flukes and tapeworms?

Answer 52

They are parasitic | Neodermata- new skin- loose epidermis – enclosed by sheath like syncytium- the neodermis- one massive nucleated cell.

Question 53

How do flatworms digest food?

Answer 53

By branched gastrovascular system - gas exchange and the elimination of nitrogenous waste occur by diffusion across the body surface and exits mouth via sac-like gut (they have no anus)

Question 54

How do flatworms move?

Answer 54

Body is covered in cilia which forces propulsion for locomotion

Question 55

How do flatworms osmoregulate?

Answer 55

With protonephridia - networks of tubules with ciliated structures called flame bulbs

Question 56

What are the similar features of the Bryozoa and Brachiopoda?

Answer 56

They are known as lophophorates. The animals have a lophophore which is a crown of ciliated tentacles around the mouth Have a true coelom

Question 57

What is an important characteristic of Bryozoa?

Answer 57

It also has a statoblast - asexually produced encapsulated bud of a freshwater bryozoan

Question 58

What are three features of Brachiopods?

Answer 58

- Sessile - Resemble bivalve molluscs - Shells on dorsal and ventral sides

Question 59

What is the difference between articulate and inarticulate brachiopods?

Answer 59

Articulate - Teeth and sockets | Inarticulate - No teeth - use system of muscles instead

Question 60

What is the function of the pedicle in Brachiopods?

Answer 60

Attaches animal to seabed

Question 61

What does "Lingula" mean

Answer 61

A living fossil