Lecture 13- From Cell to Organism

Question 1

cell proliferation

Answer 1

producing many cells from one

Question 2

cell specialization

Answer 2

creating cells with different characteristics

Question 3

cell interaction

Answer 3

coordinating the behavior of one cell with that of its neighbors

Question 4

cell movement

Answer 4

rearranging the cells to form structured tissues and organs

Question 5

major events of embryonic development (embryogenesis)

Answer 5

• fertilization
• cleavage
• gastrulation
• neurulation
• organogenesis

Question 6

fertilization

Answer 6

• unites two haploid genomes forming a diploid zygote
• species-specific
• one sperm fertilizes one egg
• activates embryonic development

Question 7

oocyte (egg)

Answer 7

• haploid nucleus

- maternal components

Question 8

maternal components of oocyte

Answer 8

• nutrients
• biosynthetic machinery
• mitochondria
• information (mRNAs and proteins) essential for early embryonic development

Question 9

sperm

Answer 9

• haploid nucleus
• centrosome (microtubule organizing center)
• activates development

Question 10

embryonic development

Answer 10

• very early phase almost entirely driven/controlled by maternal components
• embryo makes its own gene products later

Question 11

cleavage

Answer 11

• special type of cell division characterized by rapid cell division without cell growth
• cleavage cell cycles lack G1 and G2 phases
• divisions rely on maternal components

Question 12

blastomeres

Answer 12

cells generated by cleavage

Question 13

blastula

Answer 13

term for embryo at the end of cleavage

Question 14

gastrulation

Answer 14

• reorganizes embryo and results in formation of 3 distinct germ layers: Endoderm, Mesoderm, Ectoderm
• first morphogenetic event in embryogenesis

Question 15

germ cells

Answer 15

usually set aside early in development even before gastrulation (insert picture)

Question 16

morphogenesis

Answer 16

• generation of organized forms

- based on different behaviors of cells

Question 17

3 major axes visible in most organisms

Answer 17

• anterior-posterior (head/tail)
• dorsal-ventral (back/belly)
• left-right (lateral)

Question 18

neurulation

Answer 18

• formation of the central nervous system

- another major morphogenetic event in embryogenesis

Question 19

organogenesis

Answer 19

• formation of organs (internal organs, limbs, sensory organs)
• another major morphogenetic event in embryogenesis

Question 20

order from single cell to organism

Answer 20

(see chart)

Question 21

how do we study development?

Answer 21

• descriptive embryology
• experimental embryology
• developmental genetics
• comparative embryology

Question 22

fate mapping (lineage tracing)

Answer 22

label one or a group of cells early during development, and monitor what they become later

Question 23

experimental embryology

Answer 23

• experimentally manipulate the embryo: remove, rearrange, transplant, or grow part in isolation, etc.
• possible in embryos that are relatively big and easy to manipulate such as sea urchin/chick/frog

Question 24

developmental genetics

Answer 24

• the study of mutants

- possible in organisms that are amenable for genetic analysis such as worm/fly/mouse

Question 25

comparative embryology

Answer 25

evolutionary developmental biology (evo devo)