reproductive strategies and biodiversity

Question 1

Asexual reproduction

Answer 1

Asexual reproduction occurs when only one individual gives rise to the next generation

Question 2

Types of asexual reproduction

Answer 2

• Binary fission
• Spores
• Vegetative reproduction
• Parthenogenesis
• Fragmentation
• Budding

Question 3

Binary Fission

Answer 3

• Function: Reproduction
• Occurs in unicellular organisms
• No spindle forms
• Stages include chromosome duplication, chromosome segregation, cytokinesis
• Product: two cells with identical genomes

Question 4

Budding

Answer 4

• When a fully formed individual breaks off the adult
• The budded individual may need to grow before it can also product a bud

Question 5

Fragmentation

Answer 5

• When organisms reproduce by breaking into pieces
• Each piece will regenerate any missing bits
• Fragmentation can occur deliberately or as a result of damage
• Occurs in planaria, starfish, and many plants

Question 6

Vegetative propagation

Answer 6

• When a piece of plant breaks off or is removed and it grows into a fully formed individual (clone)
• E.g. grafting, the budding of the potato tuber and other roots

Question 7

Spores

Answer 7

Spores are cells which can grow into a new plant

Question 8

Parthenogenesis

Answer 8

The development of a new individual from an unfertilised egg

Question 9

Advantages of asexual reproduction

Answer 9

• Saves time and energy
• Can produce many offspring quickly
• Offspring are genetically identical to parent

Question 10

Disadvantages of asexual reproduction

Answer 10

• Offspring have little genetic variation (aside from when mutations occur)
• Increased competition for limited resources

Question 11

Sexual reproduction

Answer 11

Sexual reproduction involves the fusion of gametes from two different parents to form a zygote

Question 12

Disadvantages of sexual reproduction

Answer 12

• Lots of time and energy is needed to find a mate
• Only half of a parent’s genetic material is in the offspring

Question 13

Advantages of sexual reproduction

Answer 13

• Offspring are very varied and therefore have a higher chance of having a beneficial trait if the environment changes
• Less competition for resources between offspring

Question 14

Cloning

Answer 14

Cloning is the process of producing genetically identical copies of an individual organism. Plants and animals can be cloned.

Question 15

Types of cloning of animals

Answer 15

• Nuclear transfer
• Embryo splitting

Question 16

Nuclear transfer

Answer 16

• Causes abnormalities in offspring
• Offspring aren’t truly identical

Question 16

Adaptation

Answer 16

An adaptation is an inherited characteristic that makes an organism better suited for the environment to increase it’s chances of survival and reproduction

Question 17

Types of adaptation

Answer 17

• Structural
• Physiological
• Behavioural

Question 18

Structural adaptation

Answer 18

A change in physical/anatomical features

Question 19

Behavioural adaptation

Answer 19

A change in the way an organism acts

Question 19

Physiological adaptation

Answer 19

A change in functioning

Question 20

Symbiotic relationships

Answer 20

Close relationships between species

Question 21

Types of symbiosis

Answer 21

• Parasitism
• Mutualism
• Commensalism
• Amensalism

Question 22

Parasitism

Answer 22

Where a parasite lives on or is in a host. The host provides food and/or shelter, and the parasite will kill the host slowly if at all.

Question 23

Mutualism

Answer 23

Where both species benefit

Question 24

Commensalism

Answer 24

Where one species benefits and the other neither benefits nor is harmed

Question 25

Amensalism

Answer 25

One species is harmed and the other is neither benefited or harmed

Question 26

Keystone species

Answer 26

A keystone species is a species with a dramatically large effect on an ecosystem relative to its abundance

Question 27

Food chains/food webs

Answer 27

Food chains show the movement of energy through an ecosystem

Question 28

Describe the typical structure of a food chain

Answer 28

Sunlight --> Producer --> Primary consumer (herbivore) --> Secondary consumer --> Tertiary consumer --> Top carnivore Each level of the food chain is called a trophic level

Question 29

Abundance

Answer 29

The number of organisms of a particular species

Question 30

Distrubution

Answer 30

How the members of a species are spread through a particular area (uniform, random, clumped)

Question 31

Density

Answer 31

The number of individuals per unit area Density can vary throughout the year