Ch 50&51 Reproduction & Development

Question 1

• Single parent
– genes of offspring identical to parent’s
(except for mutations)
• Benefits
– energy efficient
– easy for sessile or isolated animals
– most successful in a stable environment

Answer 1

Asexual Reproduction

Question 2

– part of parent’s body grows, detaches

Answer 2

Budding (asexual reproduction)

Question 3

– parent’s body breaks into pieces

Answer 3

Fragmentation (asexual reproduction)

Question 4

– unfertilized egg develops into adult;

-e.g. haploid honeybee males

Answer 4

Parthenogenesis (asexual reproduction)

Question 5

• Occurs in most animals
• Fusion of two types of gametes (egg and sperm) produces offspring
– a fertilized egg (zygote)
• Benefits
– genetic variety (more genes and new mixtures)
– adaptive in unstable, changing environment
– removal of bad mutations and sharing of good mutations

Answer 5

Sexual Reproduction

Question 6

Individual produces both eggs and sperm
– most hermaphrodites don’t self fertilize (think about flowers)
– usually reciprocally fertilize other individuals to gain full advantages of sexual reproduction
– self-fertilization usually only occurs when mates are not available

Answer 6

Hermaphroditism

Question 7

– mating partners release eggs and sperm into water simultaneously

Answer 7

External fertilization

Question 8

– male delivers sperm into female’s body
– essential in terrestrial habitats
– also less left to chance
– greater investment of parental care

Answer 8

Internal fertilization

Question 9

• In seminiferous tubules of testes
• Spermatogonia divide by mitosis
– some differentiate and become primary spermatocytes, which undergo meiosis

Answer 9

Spermatogenesis

Question 10

– produces two haploid secondary spermatocytes

Answer 10

First meiotic division

Question 11

– each secondary spermatocyte produce two spermatids

Answer 11

Second meiotic division

Question 12

Each _______ differentiates
– to form a mature sperm
• 4 total from 1 primary spermatocyte

Answer 12

Spermatid

Question 13

• Oogonia
• Follicle
– During a menstrual cycle, primary oocyte completes first meiotic division, giving rise to haploid secondary oocyte and a polar body
– zona pullucida

Answer 13

Oogenesis

Question 14

Present before birth
– differentiate into diploid primary oocytes also before birth
– meiosis begins but suspended near beginning

Answer 14

Oogonia

Question 15

Consists of
– a primary oocyte with granulosa
– cells surrounding it

Answer 15

Follicle

Question 16

Layer of glycoproteins surrounding oocyte

Answer 16

Zona pullucida

Question 17

• Sperm releases enzymes to penetrate layer of follicle cells
• After sperm enters, secondary oocyte completes its second
meiotic division producing an ovum and a second polar body
• Sperm head enlarges into male pronucleus to fuse with female pronucleus

Answer 17

Human Fertilization

Question 18

Fusion of ovum and sperm

– to form a zygote

Answer 18

Fertilization

Question 19

– fertilization and establishment of pregnancy

Answer 19

Conception

Question 20

Fertilization requires __________ __ ___________
– between proteins of noncellular egg coverings (in mammals: zona pellucida) and sperm
• prevents interspecific fertilization

Answer 20

contact and recognition

Question 21

Following fertilization, ______ alter receptors on the zona pellucida
– preventing sperm from binding
• prevents polyspermy

Answer 21

Enzymes

Question 22

Fertilization of egg by more than one sperm

Answer 22

Polyspermy

Question 23

Is totipotent (can give rise to any cell type)

Answer 23

Zygote

Question 24

Process by which a cell becomes specialized to carry out specific functions

Answer 24

Differentiation

Question 25

– molecular events leading to permanent cell differentiation

Answer 25

Cell determination

Question 26

Relatively undifferentiated cells

– retain ability to form different cell types

Answer 26

Stem Cells

Question 27

• The development of form

– occurs through pattern formation

Answer 27

Morphogenesis

Question 28

Cells
– communicate by signaling
– migrate
– undergo changes in shape
– some undergo apoptosis (programmed death cells)

Answer 28

Pattern formation

Question 29

Three-layered embryo
– forming the distinct germ layers
– ectoderm, mesoderm, endoderm

Answer 29

Gastrula

Question 30

• The process of organ formation

Answer 30

Organogenesis

Question 31

• Marked by a decrease in homeostatic response to stress
– less evidence for apoptosis as a factor
• All body systems decline with age. Age of what?
– but not at the same rate
– cells with greater differentiation tend to age faster
– What about germ vs. somatic cells?

Answer 31

The Aging Process

Question 32

Programmed Death Cells

Answer 32

Apoptosis

Question 33

Lead to sperm/egg

Answer 33

Germ

Question 34

Body cells don’t contribute to next generation

Answer 34

Somatic