Chapter 13

Question 1

What is reproduction?

Answer 1

The biological process by which organisms produce new individuals

Question 2

What is asexual reproduction?

Answer 2

Production of genetically identical offspring from one parent without gametes; uses mitosis

Question 3

Advantages of asexual reproduction?

Answer 3

Fast

No mate needed

Efficient colony growth

Low energy cost

Question 4

Disadvantages of asexual reproduction?

Answer 4

No genetic diversity

Entire population vulnerable to disease or change

Poor long-term adaptability

Question 5

What is sexual reproduction?

Answer 5

Fusion of haploid gametes (sperm + egg) to form a diploid zygote
- uses meiosis
- increases genetic diversity

Question 6

Advantages of sexual reproduction?

Answer 6

High genetic diversity

Better adaptation to environmental change

Fuels natural selection

Question 7

Disadvantages of sexual reproduction?

Answer 7

Requires finding a mate

Slower

Requires meiosis and gamete production

Often involves higher energy/parental investment

Question 8

What is binary fission?

Answer 8

Equal division of a single cell into two genetically identical cells

Question 9

Example of binary fission?

Answer 9

Bacteria, amoeba, paramecium

Question 10

Photo ID cues for binary fission?

Answer 10

Two equal-sized cells splitting symmetrically, duplicated nuclei

Question 11

What is budding?

Answer 11

Unequal division where a small outgrowth (bud) forms on the parent and becomes a new organism

Question 12

Examples of budding?

Answer 12

Yeast, Hydra, some sponges

Question 13

Photo ID cues for budding?

Answer 13

Small “mini-me” projecting from parent; in hydra: baby hydra attached to side with tiny tentacles

Question 14

What is spore formation?

Answer 14

Production of unicellular dispersal spores (often haploid) that grow into new organisms

Question 15

Examples of spore formation?

Answer 15

Penicillium mold, many fungi

Question 16

Photo ID cues for spore formation?

Answer 16

Brush-like conidiophores, green mold patches, chains of spores

Question 17

What is fragmentation?

Answer 17

Body breaks into pieces and each fragment regenerates missing parts to form new individuals

Question 18

Examples of fragmentation

Answer 18

Planaria (flatworms), sea stars

Question 19

What is regeneration?

Answer 19

Regrowth of lost body parts; not reproduction unless it forms a whole new organism.
Example: lizard tail regrowth (not reproductive)

Question 20

What is parthenogenesis?

Answer 20

Development of an embryo from an unfertilized diploid egg
- produces a clone of the mother

Question 21

Examples of parthenogenesis?

Answer 21

Komodo dragons, some sharks, whiptail lizards, some bees/ants

Question 22

What is tissue culture?

Answer 22

Growing entire plants from a few parent cells in sterile media
- produces clones

Question 23

Advantages of tissue culture?

Answer 23

Identical crops, predictable traits

Question 24

Disadvantages of tissue culture?

Answer 24

Low genetic diversity → high vulnerability to disease
- requires pesticides

Question 25

What is a life cycle?

Answer 25

Sequence of events from one generation to the next (growth → reproduction → offspring)

Question 26

What is fertilization?

Answer 26

Fusion of haploid sperm and egg to form a diploid zygote

Question 27

What are gametes?

Answer 27

Haploid sex cells (sperm + egg)

Question 28

What is a haploid cell (n)?

Answer 28

Cell with one set of chromosomes

Question 29

What is a diploid cell (2n)?

Answer 29

Cell with two sets of chromosomes (one from each parent)

Question 30

What is a zygote?

Answer 30

Fertilized egg; first diploid cell of a new organism

Question 31

What does monoicous mean?

Answer 31

One individual has both male and female reproductive structures

Question 32

What does dioicous mean?

Answer 32

Male and female reproductive structures are on separate individuals

Question 33

Purpose of mitosis?

Answer 33

Growth, repair, and asexual reproduction; produces 2 identical diploid cells

Question 34

Purpose of meiosis?

Answer 34

To make haploid gametes for sexual reproduction; increases genetic diversity

Question 35

Key differences: mitosis vs meiosis?

Answer 35

Mitosis: 1 division, 2 identical cells, no crossing over. Meiosis: 2 divisions, 4 different haploid cells, homologs separate in Meiosis I, crossing over

Question 36

What is crossing over?

Answer 36

Exchange of DNA between non-sister chromatids during Prophase I → increases genetic diversity

Question 37

What separates in meiosis I?

Answer 37

Homologous chromosomes

Question 38

What separates in meiosis II?

Answer 38

Sister chromatids

Question 39

What is oogenesis?

Answer 39

Formation of eggs; produces 1 large egg + polar bodies

Question 40

Why does oogenesis produce only one functional egg?

Answer 40

Egg needs all cytoplasm to support early embryo development

Question 41

When does oogenesis begin?

Answer 41

Before birth; arrests; finishes after puberty

Question 42

What is spermatogenesis?

Answer 42

Formation of sperm; produces 4 small functional sperm

Question 42

What is a polar body?

Answer 42

Haploid cell with DNA but little cytoplasm; nonfunctional by-product of oogenesis

Question 43

Why are sperm small?

Answer 43

They specialize in mobility and delivering DNA; minimal cytoplasm

Question 44

What is in vitro fertilization (IVF)?

Answer 44

Eggs are collected, combined with sperm in a lab, resulting embryos are implanted into uterus

Question 45

What is cloning?

Answer 45

Producing a genetically identical organism from a somatic diploid cell (e.g., Dolly the sheep).

Question 46

Major difference between IVF and cloning?

Answer 46

IVF: normal sexual reproduction (sperm + egg). Cloning: no fertilization; uses DNA from one individual → genetic clone