Reproduction

Question 1

Fusion of two specialized cells, or
gametes (one male, one female)
Most common strategy in vertebrates

Answer 1

Sexual Reproduction

Question 2

Involves only one parent, No special reproductive organs or cells (no formation of gametes), Produces genetically identical offspring (clones), Widespread in bacteria, unicellular
eukaryotes, and many invertebrates, Rare among vertebrates

Answer 2

Asexual Reproduction

Question 3

Advantages Of Asexual Reproduction

Answer 3

Quick and energy efficient

Sexual reproduction takes about twice
as long as asexual reproduction (in
species that do both)

Question 4

Disadvantages Of Asexual Reproduction

Answer 4

Phenotypic diversity depends on mutation

‘Muller’s Ratchet’: Accumulation of
deleterious mutations

Asexual reproduction can’t produce a
genome with less deleterious mutations
than the parent (sexual reproduction can)

Question 5

Advantages of Sexual Reproduction

Answer 5

Debated – several theories

Main advantage (?): Ability to mix and match successful genes (more rare or novel
genotypes)

Organisms with asexual reproduction depend on mutation for genetic variation

Question 6

Disdvantages of Sexual Reproduction

Answer 6

Energetically costly (courtship, defence…)

Main disadvantage: males do not directly
produce offspring

‘twofold’ cost of sex (John Maynard Smith, 1971)

Question 7

Types of Asexual Reproduction (5)

Answer 7

1. Binary Fission
2. Multiple Fission (Schizogony)
3. Budding
4. Gemmulation
5. Fragmentation

Question 8

Common among bacteria and protozoa

The parent divides by mitosis into two parts

Each grows into an individual similar to the parent

Answer 8

Binary Fission

Question 9

Nucleus divides repeatedly

Cytoplasmic division then produces many daughter cells
simultaneously

Answer 9

Multiple Fission or Schizogony

Question 10

Unequal division of an organism

Bud is an outgrowth of the parent

Develops organs and then detaches

Answer 10

Budding

Question 11

Formation of a new individual from an aggregation of cells

Cells are surrounded by a resistant capsule – a “gemmule”

Answer 11

Gemmulation

Question 12

Like ‘binary fission’ for multicellular animals

Breaks into two or more fragments that
become a new individual

Different from budding because each
fragment grows new parts

Answer 12

Fragmentation

Question 13

Generally involves two parents

Specialized germ cells unite to form a zygote

Recombines parental characters

Results in a more diverse population

Answer 13

Sexual Reproduction

Question 14

Types of Sexual Reproduction (3)

Answer 14

Bisexual
Hermphroditism
Pathenogenesis (can be considered asexual)

Question 15

Male and female gametes (sperm or egg) are produced. Two haploid (n) gametes combine to form a zygote (2n)

Answer 15

Bisexual reproduction

Question 16

Male and female organs occur in same individual

Most avoid self-fertilization

Answer 16

Hermaphroditism

Question 17

Embryo develops from unfertilized egg

Sperm may activate but not fuse with egg

Answer 17

Parthenogenesis

Question 18

Having male and female gonads in separate individuals

Answer 18

Dioecious

Question 19

Having both male and
female gonads in the same organism;
hermaphroditic

Answer 19

Monoecious

Question 20

Reproduction in which eggs are released by the female.

Development of offspring occurs outside the
maternal body.

External or internal fertilization

Answer 20

Oviparous

Question 21

Reproduction in which eggs develop within the female body, which provides nutritional aid

Internal fertilization

Answer 21

Viviparous

Question 22

Reproduction in which eggs develop within the maternal body without additional nourishment from
the parent

Hatch within the parent or immediately after laying.

Internal fertilization

Derive nourishment from yolk, not from mother

Answer 22

Ovoviviparous