Reproduction

Question 1

Sexual selection advantages

Answer 1

Ability to mix and match successful genes

Question 2

Sexual selection disadvantages

Answer 2

• Energetically costly
• Males don’t directly produce offspring

Question 3

Types of sexual selection

Answer 3

• Bisexual reproduction
• Hermaphroditism
• Parthenogenesis

Question 4

Bisexual reproduciton

Answer 4

• Male/female gametes are produced
• 2 gametes combine to form zygote
• Most common form

Question 5

Hemaphroditism

Answer 5

Male and female organs occur in same individual
* Simultaneous hermaphroditism: active female and male organs at the same time
* Sequential hermaphroditisum: active sex changes at some point during life

Question 6

Parthenogenesis

Answer 6

• Embryo develops from unfertilized egg
• Offspring are formed from gametes but only one parent contributes genetic materia

Question 7

Haploid parthenogenesis

Answer 7

• Haploid ovum formed by meiosis
• Occurs in some bees and nematodes

Question 8

Diploid parthenogenesis

Answer 8

Meiosis occurs but diploid condition is restored
* Chromosomal duplication
* Autogamy
* Offspring are not clones of parent

No meiosis occurs
* asexual form of parthenogeneis
* Offspring are clones of the parent

Question 9

Asexual reproduction advantages

Answer 9

Quick and energy efficient

Question 10

Asexual reproduction disadvantages

Answer 10

• Phenotypic diversity depends on mutations
• ‘Mullers Ratchet’: Accumulation of deleterious mutations

Question 11

Types of asexual reproduciton

Answer 11

• Binary fission
• Mutliple fission (schizogony)
• Budding
• Gemmulation
• Fragmentation

Question 12

Binary fission

Answer 12

• The parent divides by mitosis into 2 parts
• Common in bacteria/protozoa

Question 13

Multiple fission (schizogony)

Answer 13

• Nucleus divides repeatedly followed by cytoplasmic division
• Sporogony: Special case of schizogony leading to spore formation

Question 14

Budding

Answer 14

Unequal division of an organism
* Bud = outgrowth of parent

Question 15

Gemmulation

Answer 15

Formation of a new individual from an aggregation of cells
* Gemmule = resistant capsule around cells

Question 16

Fragmentation

Answer 16

Like binary fission for multicellular animals
* Breaks into 2 or more fragments that becomes a new individual
* Different from budding because each fragment grows new parts

Question 17

Reproduction strategies

Answer 17

• r-selected reproduction
• k-selected reproduction

Question 18

r-selected reproduction

Answer 18

• short life expectancy
• Many offpring (thousands)
• Low % survival
• No parental care
• No parental nourishment

Question 19

k-selected reproduction

Answer 19

• Long life expectancy
• Few offspring
• High % survival
• Parental care
• Nourish embryo

Question 20

Monoecious

Answer 20

Having both male and female gonads in the same organism

Question 21

Dioecious

Answer 21

Having male and female gonads in separate individuals

Question 22

Oviparous

Answer 22

• eggs are released by the female
• Development of offspring occurs outside the maternal body
• External or Internal fertilization

Question 23

Viviparous

Answer 23

• Eggs develop within female body
• Development of offspring occurs inside the maternal body
• Internal fertilization

Question 24

Ovoviviparous

Answer 24

• Eggs develop within maternal body without additional nourishment from the parent
• Hatch within the parent or immediately after laying
• Internal fertilization
• Derive nourishment from yolk

Question 25

Precocial developmental state

Birds and mammals

Answer 25

• Hatch covered with down
• Can run/swim
• Most can’t fly
• Fairly independent

Question 26

Altricial Develomental state

Answer 26

• Smaller eggs, less yolk
• Hatch naked
• Blind, can’t walk
• Remain in nest for 1-2 weeks
• Fed constantly by parents