EXAM 3 REVIEW

Question 1

Where does fertilization occur in humans?

Answer 1

-In the upper third of the oviduct

Question 2

Which stages is produced by the cleavage alone?

Answer 2

• Morula

- Blastula

Question 3

How many germ layers are produced in embryos?

Answer 3

3

Question 4

What is the name of the location of where the germ layers are produced?

Answer 4

-Gastrula

Question 5

What is the characteristic of sea urchin eggs in terms of their polarity?

Answer 5

-Animal/ vegetal poles are determined by position of the nucleus so when a sea-urhcin egg is cut vertically in half they’ll develop normally

Question 6

What did the experiments of the Xenopus eggs w/ antibiotic actinomycin D demonstrate?

Answer 6

-That early development requires maternal mRNA

Question 7

What are Morphogens?

Answer 7

-They are signalling molecules that establish the Anterior-Posterior axis in development

Question 8

What is the process of development?

Answer 8

• Cell division
• Differentitation
• Pattern Formation
• Morphogenesis

Question 9

What is an important characteristic of Morphogens?

Answer 9

-They diffuse from their source to produce a concentration gradient

Question 10

What is the purpose of Apoptosis during development?

Answer 10

-It sculpts the body structures

Question 11

What are the Homeobox-containing (HOX) genes?

Answer 11

-They code for products that establish the segment fate in an embryo

Question 12

What is an important characteristic of Hox genes?

Answer 12

-They contain a highly conserved DNA sequence

Question 13

How is the human lens formed during development?

Answer 13

-It’s formed via induction during development

Question 14

What are important characteristics of stem cells?

Answer 14

• They are found in your body

- They respond to Molecular differentiation cells

Question 15

What occurs to the ligand when a pre-synaptic neuron releases an inhibitory transmitter?

Answer 15

-It’ll bind to receptors on the dendrites of the post-synaptic neuron and cause the cell to hyperpolarize

Question 16

What occurs when skeletal muscles are at rest?

Answer 16

ADP and Pi are bounded to the myosin heads

Question 17

What is a characteristic of Type I muscle fibers?

Answer 17

-They contain high capacity for Aerobic respiration

Question 18

What role do T-Tubules play?

Answer 18

-They propogate action potential through a myofiber

Question 19

Where is Myoglobin most abundant?

Answer 19

-It is more abundant in your smaller diameter muscle fibers

Question 20

What happens if ATP is not available to skeletal muscle?

Answer 20

• The rigor mortis could occur

- The cross bridges couldn’t be broken

Question 21

What is required for skeletal muscle to produce it’s sliding filament action?

Answer 21

• ATP hydrolysis at the myosin heads

- Calcium binding to troponin

Question 22

What causes your muscle to bulge when you flex your arm?

Answer 22

-The sarcomere thickens bc actin myofilaments slide past myosin myofilaments

Question 23

How is skeletal muscle organized?

Answer 23

-It’ organized into smooth sarcomeres

Question 24

How does cardiac muscle look like?

Answer 24

-It has intercalated disks

Question 25

What causes the degeneration of neurons in ALS?

Answer 25

-When toxins are secreted by neuronal support cells

Question 26

What results in the muscle degeneration in ALS?

Answer 26

-When the motor neurons degenerate

Question 27

Why are my skeletal muscles multinucleated?

Answer 27

-Bc of the multiple myoblasts that were fused together during embyronic development

Question 28

What is Acetylcholine?

Answer 28

-A neurotransmitter

Question 29

How is Acetylcholine broken down?

Answer 29

-By enzymes that were secreted by the post-synaptic cell