Invertebrates 6

Question 1

Myriapods. Example?

Answer 1

2 body regions:
- Head(two jaws, antennae and simple eyes)
-Trunk
Ex. millipede, centipede

Question 2

Centipede

Answer 2

-One pair of appendages per segment(one antennae, one simple, two jaws)
-Carnivores
-Internal fertilisation(separate sexes)

Question 3

Milipede

Answer 3

-Two pairs of appendages(two antennae, two simple eyes, four jaws)
-Herbivores, Detritivores
-Internal fertilisation(separate sexes)

Question 4

Chelicerates

Answer 4

2 body regions:
1. Cephalothorax(body region with appendages)
2. Abdomen (body region with no appendages)
-No jaw and no antennae
-Internal fertilisation (sexes separated)
Example: spider, mites

Question 5

Six pairs of appendages on chelicerates?

Answer 5

1. Fangs
2. Pincers, sensory organs or locomotion
3. Walking legs
4. Walking legs
5. Walking legs
6. Walking legs

Question 6

Crusteaceans(body regions and their appendages, external/internal fertilization

Answer 6

3 body regions:
1. Head: 3 pairs of feeding appendages, 2 pairs of antennae
2. Thorax: legs for walking/feeding
3. Abdomen: legs for swimming
Separate sexes(internal fertilization)

Question 7

How do daphnia reproduce?

Answer 7

Through cyclical pathogenesis. Daphnia alternate between asexual and sexual reproduction.

Question 8

How do daphnia produce in good environmental conditions?

Answer 8

When environmental conditions are favourable(lots of water and food) daphnia will produce diploid eggs asexually that will develop into parthenogenetic daughters(identical to their mother)(this cycle will continue until environmental conditions become unfavourable)

Question 9

How do daphnia reproduce in bad environmental conditions?

Answer 9

During unfavourable conditions the same female daphnia will produce a genetically identical son who will mate with other daphnia sexually

Question 10

What is the obligate parthenogenetic life cycle?

Answer 10

Some daphnia lost the ability to reproduce sexually and are therefore forced to reproduce asexually(always produce diploid eggs). Females can still produce males

Question 11

Insects(body regions and their appendages

Answer 11

-3 body regions
1. Head: antennae, mouth parts , compound eye
2. Thorax: 3 pairs of walking legs, can have wings
3. Abdomen: no appendages
Sexual reproduction and metamorphosis

Question 12

What is unique to insects?

Answer 12

Insects have external mouth parts(different feeding strategies causes different mouth parts)

Question 13

Wings

Answer 13

the wings of an insect and gills of a crayfish are homologous(common ancestral root)

Question 14

How do insects benefit ecosystems?

Answer 14

-Pollination
-Decomposers
-Biological control of pests
-Food source
-Dispersal agent

Question 15

What is causing insects to decline?

Answer 15

• insecticides
  -Habitat loss
  -Pollution
  -Disease
  -Climate change

Question 16

Are echinoderm protostomes or deuterostomes?

Answer 16

PROTOSTOMES

Question 17

Are sponges and cnidaria protostomes or deuterostomes?

Answer 17

NEITHER
Cnidaria have a blind gut
And sponges don’t have a mouth or anus(they have pores)

Question 18

What two groups make up the deuterostomes?

Answer 18

-Chordates
-Echinoderms

Question 19

How do echinoderms reproduce?

Answer 19

Sexually by external fertilization. Eggs and Sperms are released into the water and the fertilized egg hatches into free-swimming larvae and settles to the bottom of the water and develops via metamorphosis into an adult

Question 20

How are echinoderms similar to other deuterostomes?

Answer 20

-Triploblastic
-True body cavity
-Bilateral symmetry during larval stage
- Complete digestive tract

Question 21

How are echinoderms different to other deuterostomes?

Answer 21

-No segmentation
-No cephalization(no head/brain)
-Bilateral symmetry in the adult form

Question 22

what are derived characteristics?

Answer 22

A trait that arose in the most recent common ancestor

Question 23

What are the 4 derived characteristics of echinoderms?

Answer 23

Water-vascular system:
- Used for locomotion, feeding, excretion and gas exchange
Dermal Endoskeleton:
- Hard skeleton composed of CaCO3 plates and spines
-Plates grow continuously
Hemal system: lack true circulatory system (hemal system distributes nutrients)
Pentaradial symmetry