SAC 5 (ecosystems)

Question 1

Abiotic factors

Answer 1

• metals, gases (O2), water

Question 2

Biotic factors

Answer 2

• living or have lived (animals, trees)

Question 3

Asexual Reproduction Definition

Answer 3

• is a type of reproduction that does not require the fusion of gametes
• offspring are genetically identical to the parent

Question 4

Asexual Reproduction - Different Types

Answer 4

• binary fission
• budding (produced as bud/growth)
• vegetative propagation (part of plants being detached & developing)
• fragmentation

Question 5

Asexual Reproduction - Advantages

Answer 5

• requiring only one parent, conserving energy
• organisms can quickly reproduced under favourable conditions
• advantageous in stable environments

Question 6

Asexual Reproduction - Disadvantages

Answer 6

• does not produce genetic variation
• only genetic variation is mutation
• rapid population growth

Question 7

Sexual reproduction

Answer 7

• can occur internally or externally

Question 8

Internal Fertilisation

Answer 8

• is the process of fertilisation that occurs inside the body (oviparity, ovoviviparity, viviparity)

Question 9

Advantages of Internal Fertilisation

Answer 9

• increased fertilisation probability
• mates are selective
• young is protected against predators, increased survival

Question 10

External Fertilisation

Answer 10

• occurs outside the body of an organism, usually requires water
• spawning (leads to higher genetic diversity)

Question 11

Adv & Dis of External Fertilisation

Answer 11

• increased genetic variation (adv)
• produce large number of offspring (adv)
• large amount of gametes are wasted (dis)
• desiccation zygotes (dis)

Question 12

Surface-Area to volume ratio and heat loss

Answer 12

• small body = higher surface area: volume ratio (release heat)
• large body = lower surface area: volume ratio (maintain heat)

Question 13

Adaptations

Answer 13

• a genetically controlled structural, behavioural or physiological feature that enhances the survival of organisms in a particular environmental conditions

Question 14

Structural

Answer 14

• physical features (feathers)

Question 15

Physiological

Answer 15

• body processes (respiration)

Question 16

Behavioural

Answer 16

• the way an organism acts/actions performed (mating dance)

Question 17

Carrying capacity of a habitat

Answer 17

• a species average population size in a particular habitat

Question 18

Indigenous management techniques

Answer 18

• Fire (controlled burning to manage animal population and promote vegetative growth
• Hunting (hunting of particular species to control population density)

Question 19

Interactions between ecosystems

Answer 19

• mutualism: both species benefit
• commensalism: one species benefits and other is not affected
• parasitism: one species benefits at the expense of another

Question 20

Species richness

Answer 20

• Species richness is defined as the number of different species in a region – this is the total number of species (both plant and animal) that you counted for each location.

Question 21

Species evenness

Answer 21

• Species evenness refers to how balanced the numbers of each species in a habit are. Instead, you evaluated the abundance of the species as low, medium, or high

Question 22

Population density and size

Answer 22

• Population size is the number of species in a population
• Population density is the average number of species per unit of area or volume

Question 23

Sexual v asexual reproduction in plants

Answer 23

• asexual reproduction: without seeds
• sexual reproduction: with seeds

Question 24

Cloning-embryo splitting

Answer 24

1. Remove DNA from donor ovum, so it has no DNA
2. Nucleus from somatic cell is transferred to donor ovum
3. Ovum is shock to stimulate mitosis
4. Cell division until the embryo becomes a blastocyst
5. Implant into surrogate mother

Question 25

Cloning-somatic cell nuclear transfer

Answer 25

Uses a different approach than artificial embryo twinning, but still produces an genetic copy of an individual

Question 26

Cloning-plants

Answer 26

• Cloning plants is just to take the cutting/clipping of a plant and grow it elsewhere on its own

Question 27

Gene pool

Answer 27

• the combination of all the genes present in a reproducing population or species

Question 28

Genetic diversity

Answer 28

• the biological variation that occurs within species