Lesson 7 - Variation

Question 1

Adaptations:

Answer 1

Characteristics that increase an organism’s chance of survival and reproduction in its environment.

Question 2

Three divisions of adaptations?

Answer 2

• Anatomical adaptations (physical features / internal and external)
• Behavioural adaptations (the way an organism acts. These can be inherited or learnt from their parents)
• Physiological adaptations (processes that take place inside the body)

Question 3

Examples of Anatomical adaptations:

Answer 3

• Body covering
• Camouflage
• Teeth
• Mimicry

Question 4

Anatomical adaptations:
Body coverings:

Answer 4

• Hair
• Scales
• Spines
• Feathers
• Shells

Help an organism to fly, stay warm and provide protection.

• Thick waxy layers on plants prevent water loss
• Spikes deter herbivores and protect tissues from sun damage.

Question 5

Anatomical adaptations:
Camouflage:

Answer 5

• Outer colour of an animal allows it to blend into its environment, making it harder for predators to spot.
• Snowshoe hare is white in winter (snow) and turns brown in summer (soil/rocks)

Question 6

Anatomical adaptations:
Teeth:

Answer 6

Shape and type of teeth present in an animals jaw is related to its diet.
- Herbivores (sheep) have continuously growing molars for chewing tough grass and plants.
- Carnivores (tigers) have sharp large canines to kill prey and tear meat.

Question 7

Anatomical adaptations:
Mimicry:

Answer 7

Copying another animals appearance / sounds allows a harmless organism to fool predators into thinking it is poisonous or dangerous.
- Hoverfly mimic markings of a wasp.

Question 8

Marram Grass adaptations to reduce the rate of transpiration:

Answer 8

• Curled (rolled) leaves to minimise the surface are of moist tissue exposed to the air and protect the leaves from wind.
• Hairs on the inside of surface of the leaves trap moist air close to the leaf, reducing diffusion gradient.
• Stomata sunk into pits, which make them less likely to open / lose water.
• Thick waxy cuticle on leaves and stems, reducing water lots through evaporation.

Question 9

Behavioural adaptations:

Answer 9

• Survival behaviours
• Courtship
• Seasonal behaviours

Question 10

Behavioural adaptations:
Survival behaviours:

Answer 10

Opossum plays dead / rabbit freezes when they think they have been seen.

Question 11

Behavioural adaptations:
Courtship:

Answer 11

This increases the organisms’ chance of reproducing.

Question 12

Behavioural adaptations:
Types of seasonal behaviours:

Answer 12

• Migration (animals move from one region to another, and back again when environmental conditions are more favourable. Better climate / source of food).
• Hibernation (period of inactivity in which the animal’s body temperature / heart rate / breathing rate slow down to conserve energy, reducing animal’s requirement for food.

Question 13

Categories of behavioural adaptations:

Answer 13

• Innate (instinctive) behaviour
• Learned behaviour

Question 14

Innate behaviour:

Answer 14

Ability to do this is inherited through genes.
- Spiders create spider webs.
- Woodlice avoid light.
- Allows organism to survive in the habitat in which it lives.

Question 15

Learned behaviour:

Answer 15

Adaptations learned from experience or from observing other animals.
- Use of tools. Otters use stones to hammer shells off rocks.

Question 16

Physiological adaptations:

Answer 16

• Poison production
• Antibiotic production
• Water holding

Question 17

Physiological adaptations:
Poison production:

Answer 17

Many reptiles produce venom to kill prey and may plants produce poison on leaves to prevent themselves from being eaten.

Question 18

Physiological adaptations:
Antibiotic production:

Answer 18

Some bacteria produce antibiotics to kill other species of bacteria in the surrounding area.

Question 19

Physiological adaptations:
Water holding:

Answer 19

Water-holding from can store water in its body. This allows it to survive in the desert for more than a year without access to water.
Many cacti and other desert plants can hold large amounts of water in their tissues.

Question 20

Anatomical adaptations provide evidence for convergent evolution:

Answer 20

• Analogous structures

Question 21

Examples of analogous structures:

Answer 21

• Whale and fish tail fins perform the same role. Detail of structures are very different.
• Marsupials (Australia) and placental mammals (Americas)

Question 22

What is an analogous structure:

Answer 22

Adapted to perform the same function but have different genetic origin

Question 23

Convergent evolution:

Answer 23

Takes place when unrelated species begin to share similar traits. These similarities occur as organisms adapt to similar environments / other selection pressures.

Question 24

Similarities between placenta mammals and marsypials:

Answer 24

Placental mammals: placenta connects the embryo to mother’s circulatory system in the uterus. This nourishes the embryo, allowing it to reach a high level of maturity before birth.
Marsupials also start life in uterus, but the leave and enter the marsupium (pouch) while they are still embryos. Development completed by sucking milk.

Question 25

Examples within the placenta mammals and marisupials:

Answer 25

• Marsupial and placental mice
  Small, agile climbers that live in dense ground cover and forage at night for small food items. Similar size and body shape.
• Flying phalangers and flying squirrels
  Gliders that eat insects and plants. Skin stretched between forelimbs and hind limbs to provide a large surface area for gliding from one tree to the next.
• Marsupial and placental moles
  Burrow through soft soil to find worms and grubs. Streamlined body shape and modified forelimbs for digging. Velvety fur, allows smooth movement through soil. Differ in fur colour.
  Marsupial mole = white to orange
  Placental mole = grey

Question 26

Plant examples of convergent evolution

Answer 26

Aloe and agave –> desert.