theme 3

Question 1

why did several vertebrae separated the pectoral girdle (shoulder area bone) from the cranium (skull bone)

Answer 1

allowed the animals to move its head to scan environment and capture food

Question 2

why did Life on land required changes in sensory systems?

Answer 2

in water, body wall picks up sound vibrations and transfers them directly to sensory receptors, Sound waves are harder to detect in air, that led to appearance of ear drums to detect vibrations in air.

Question 3

What should be the condition of the skin of amphibians living in the terrestrial environment?

Answer 3

The skin must be moist and thin enough to bring blood into close contact, as blood vessels can be used as major site of gas exchange.

Question 4

why do terrestrial animals produce urea or uric acid instead of ammonia?

Answer 4

Ammonia is less expensive metabolically but it is very toxic and needs to be flushed away with water immediately, which is only done for aquatic animals.

Question 5

How did early animals overcome terrestrial environment challenges of locomotion?

Answer 5

A skeleton provides support and points of attachment for muscles, allowing locomotion and survival on land

Question 6

which animal was first on the land?

Answer 6

Arthropods

Question 7

Some animals we find on land still need water to complete lifecycle such as

Answer 7

Amphibians

Question 8

What is Parthenogenesis?

Answer 8

it is the growth and development of an unfertilized egg.

Question 9

True or False: Offspring produced by parthenogenesis may be haploid or diploid

Answer 9

True.

Question 10

Is the offspring from parthenogenesis genetically identical to the parent or to each other?

Answer 10

No, the egg from which a parthenogenetic offspring is produced derives from meiosis in the female parent.

Question 11

Is the egg in parthenogenesis diploid or haploid?

Answer 11

Parthenogenesis eggs are diploid (2N).

Question 12

What are the environmental challenges in the aquatic environment?

Answer 12

1-The density of Water causes less light availability
2- viscosity, it affects the motility of aquatic animals
3- lower oxygen content, as oxygen diffuses lower in water
4- high thermal conductance, water removes a lot of heat from living things

Question 13

how are Amniote eggs resistant to desiccation?

Answer 13

Amniote eggs keep fluid in to protect the embryo from desiccation.

Question 14

Adaptations for Desiccation avoidance

Answer 14

(mechanisms to reduce water loss)
Thick skin, Waxy cuticle
Produce concentrated insoluble Urine, Urea/Uric acid, loop of Henle
Behaviour

(mechanisms to Replace water loss)
Drink, eat moist food
Metabolic water

Question 15

What organism uses Aestivation

Answer 15

African lungfish, for desiccation tolerance

Question 16

ways for Desiccation tolerance

Answer 16

Aestivation - state of dormancy

life cycle- parthenogenesis

Question 17

what animal depends on parthenogenesis for desiccation tolerance

Answer 17

Rotifers

Question 18

In what environmental condition does a Rotifer use asexual reproduction

Answer 18

Unstressed moist conditions

Question 19

What adaptations were made for freeze tolerance

Answer 19

Ice nucleating proteins
life cycle stages
hibernation/lowering metabolism

Question 20

what adaptations were made for freeze avoidance

Answer 20

avoid by thermoregulation
avoid by behaviour

Question 21

what adaptations happened for excretion of wastes for terrestrials

Answer 21

1-Urea is less toxic and can be stored in higher concentrations, limiting water loss compared to toxic ammonia.
2-Uric acid is even less toxic and insoluble, it is a white paste in bird poo, and because it is insoluble, it can be stored or voided without risk while conserving water.

Question 22

What adaptions happened to protect reproductive structures from desiccation?

Answer 22

Gametes:
1- internal fertilization
2- mate finding

embryo:
1- aquatic larvae
2- thick covering on eggs
- amniote vertebrates surround embryos with amniotic membrane

Question 23

major challenges to living on land

Answer 23

1- desiccation
2- gravity
3- breathing air
4- sensory systems and structures

Question 24

what does high cellular CO2 concentration do and why is it bad?

Answer 24

High cellular CO2 produces changes in cellular pH, which in turn alter the activity levels of all functional proteins.
high cellular CO2 is bad because it is a narcotic poison that damages nerve function.

Question 25

what is hypoxic environment?

Answer 25

an environment that is too low on oxygen to sustain most aerobic life, particularly an aquatic environment

Question 26

How do animals adapt to hypoxic environment?

Answer 26

Marine mammals, like dolphins, come to the water’s surface to breathe and they exhibit adaptations that prolong breath-holding during diving. Many species of fish living in oxygen-poor waters have adaptations that allow them to breathe air at the water’s surface

Question 27

Does the speed of sound move faster in water or air?

Answer 27

It moves 10,000 times faster in water

Question 28

is there the same amount of O2 in the air as in water for the same partial pressure?

Answer 28

No, There is 30 times the amount of O2 in air as in water for the same partial pressure

Question 29

does it take more energy to move water than air over a respiratory surface?

Answer 29

the density of water is 1000 times that of air, and its viscosity is about 50 times that of air. Therefore, it takes significantly more energy to move water than air over a respiratory surface.

Question 30

Is there some sort of advantage or disadvantage for aquatic animals living in warm water compared to cold water when it comes to temperature or the amount of solute?

Answer 30

when either the temperature or the amount of solute increases, the amount of gas that can dissolve in water decreases. Therefore, with respect to obtaining O2, aquatic animals that live in warm water are at a disadvantage compared with those that live in cold water

Question 31

what are the advantages of breathing water for aquatic animals?

Answer 31

CO2 is 20 times more soluble in water than O2, and CO2 excretion is easily achieved as a result of the ventilation required to obtain oxygen in aquatic organisms. Thus, aquatic animals face challenges in obtaining O2 from water compared with terrestrial animals but have a much easier time eliminating CO2.

Question 32

what is a disadvantage of breathing for air-breathing organisms?

Answer 32

air constantly evaporates water from the respiratory surface unless it is saturated with water vapour. Therefore, except in an environment with 100% humidity, animals lose water by evaporation during breathing and must replace the water to keep the respiratory surface from drying.

Question 33

how does gas exchange across respiratory surfaces occur?

Answer 33

All gas exchange across respiratory surfaces occurs by diffusion

Question 34

do insects use blood to transport gases like mammals?

Answer 34

Insects do not use blood to transport these gases

Question 35

Why must gas exchange surfaces be moist?

Answer 35

Gases must first dissolve in a liquid in order to diffuse across a membrane, so all biological gas exchange systems require a moist environment. side note:In general, the higher the concentration gradient across the gas-exchanging surface, the faster the rate of diffusion across it.

Question 36

is it possible for large multicellular organisms to depend solely on diffusion for gas exchange?

Answer 36

No, animals that do so require a large surface area-to-volume ratio, only if the animal is thin and flat. in fact, bacteria can rely on diffusion solely due to their very high SA:V ratio.

Question 37

what system do insects use for gas exchange?

Answer 37

Insects Use a Tracheal System for Gas Exchange

Question 38

explain Insect Tracheal system

Answer 38

Insects breathe air through a unique respiratory system consisting of air-conducting tubes called tracheae, Air enters and leaves the tracheal system at openings in the insect’s chitinous exoskeleton called spiracles

Question 39

How do most insects and invertebrates detect vibrations and sound?

Answer 39

through mechanosensors, it then translate vibrations into nerve impulse

Question 40

What is a mechanosensor?

Answer 40

it is a tympanal organ that detects vibrations and sounds in invertebrates

Question 41

How do vertebrates detect sound?

Answer 41

auditory system

Question 42

What does pinna (outer ear) do?

Answer 42

concentrates and focuses sound waves

Question 43

What 3 auditory ossicles do mammals have?

Answer 43

malleus (hammer), incus (anvil), and stapes (stirrup)

Question 44

What is an oval window?

Answer 44

an elastic membrane where vibrations in bone are converted to vibrations in the fluid in the vestibular canal. Vibrations of the eardrum are conducted through the oval window.

Question 45

what do chemosensory structures do?

Answer 45

Chemosensors provide information about taste (gustation) and smell (olfaction)

Question 46

How do Antennae smell?

Answer 46

Antennae have hair-like chemosensory structures to smell, pores found on hair allow odor molecules to enter then dissolve to be transported through fluid and bind to receptors.

Question 47

How many inner ear bones do reptiles have and how did it evolved?

Answer 47

reptiles have one inner ear bone, it evolved from parts of the jaw.

Question 48

Does eye size matter in water?

Answer 48

no, as eye size increases, vision ability under water stays the same

Question 49

Does eye size matter in air?

Answer 49

Yes, as eye size increases, vision ability increases. millions-fold increase in space to see

Question 50

during transition, eyes

Answer 50

eyes tripled in size, and shifted from the side to the top of head