Lecture 16: More animals

Question 1

Movement

1. What are the functions of animal locomotion
2. What are the ways in which animals move, how are they powered
3. What are the three types of skeletal systems/what do they enable?

Answer 1

1. Finding food, finding mates, escaping from predators, dispersing to new habitats
2. Burrow, slither, swim, fly, crawl, walk, run (powered by muscle!)
3. 3 types:
   Hydrostatic skeletons: support from flexible body wall in tension surrounding fluid or soft tissue under compression
   Endoskeletons (we have this) derive support from rigid structures inside the body such as bones in vertebrae
   Exoskeletons- derive support from rigid sutrcutures on the outside of body such as external armor of anthropods

Question 2

What are the different types of sensory organs/stimulus/example

Answer 2

1.Sight (stimulus: light) Flies use their compund eyes to find food and mates
2.Hearing (stimulus:sound) Bats use hearing to find prey and to avoid obstacles in the dark
3. Taste/smell (Stimulus: molecules) Male moths have antennae to detect chemical signals in the air
4. Touch (stimulus: contact, pressure) See anemones detect and capture prey using touch

Question 3

Reproduction

What happens when an animal does not reproduce, but have good locomotion and feeding?

Answer 3

Alleles responsible for effective locomotion and feeding will not incerase in frequeuncy in population aka natural selection!

Question 4

Life cycles

1. Most sexually reproducing animals have what type of life cycles?
2. What is metamorphosis?
3. What contasts metamorpohsis

Answer 4

1. Sexually reproducing animals have diploid dominant life cycles
2. Drastic change from one development stage to another
3. Contrasts direct development where an animal is born a smaller version of its adult form (gradual growth)

Question 5

1. What happens during indirect development?
2. What does metamorphosis transform larvae into?
3. When are animals in their reproductive stage in their life cycles?

Answer 5

1. Embryogenesis produces larvae which look radically different from adults and live in different habitats and eat different foods
2. Metamorpohsis transforms larvae into juveniles which looks like adults, live in same habitats and eat same food, and sexually immature
3. Growth and maturation transform juveniles into **adults **

Question 6

How does the fossil record agree that non bilterian animals existed before other animals

Answer 6

1. Porifera (sponges)
2. Ctenophora (comb jellies)
3. Cnidaria (jellyfish)
   are most ancient of all major animals and predated the Cambrian explosion

Question 7

Types of limbs

What are the different modes of movement/example?

Answer 7

1. Lobe like limbs- velvet works use this to crawl
2. Tube feet- Ecinoderms like this sea star use this to crawl and grab prey
3. Jointed limbs- of anthropods (crab ie) and vertebraes are used for locomotion and feeding
4. Parapodia- polychaete worms. use bristled parapodia to crawl and swim
5. Arms and tentacles- octopuses use muscular arms to crawl to grab prey

Question 8

What are the different types of reproductive strategies?

Answer 8

1. Asexual-polyps produce via fission or budding
2. Sexual aka external fertilization- corals release eggs and sperm into water
3. Internal fertilization- Damsel-flies male. holds famel behind her head with claspers and female retrieves sperm

Question 9

Modes of embryonic development AFTER internal fertilization:

What important themes are needed to know?

Answer 9

1. Viviaparous species nourish embryos internally and give birth
2. Oviparous: species deposit fertilizated eggs and nourished in yolks
3. ovoviviparous- species retain eggs internally (noruished with yolk) and give birth to live young

Provision occurs in the egg or by the mother/locations of hatching

Question 10

1. What is the Cambrian explosion?
2. When was it, what era was it?
3. What type of body plans evolved?
4. Why is it called an explosion/ rather than something else?
5. Why did it stop?

Answer 10

1,2. 541-530 MYA (half a billion years ago in the Paleozic era), diversity of life exploded. Most of the major animal phyla appear for the first time.
3. Phylum level body plans evolved rapidly during Cambrian rather than more gradually over time.
4. It happened very fast
5. There were constraints so evolution began to slow down

Question 11

What sparked the Cambrian explosion? (hypotheses)

Answer 11

1. Oxygen levels grew rapidly so respiration/ATP production evolved
2. Rise of higher quality food sources
3. Evolution of predators
4. There were more organisms so more niches took place
5. Modified genes= modified bodies which allowed the change of specific segment innovations