Biology 2

Question 1

What comes only from the ectoderm?

Answer 1

Central Nervous system!

Epidermis from ectoderm, Dermis from mesoderm
Same with adrenals- cortex from mesoderm, medulla from ectoderm/neural crest
Small intestine from mesoderm and endoderm

Question 2

Larynx

Answer 2

• contains voice cords- skeletal muscles + cartilage used to maneuver it
• opening into larynx is glottis; covered by epiglottis

Question 3

Breathing chemoreceptors in COPD patients

Answer 3

-loss of function of CO2 chemoreceptors = respond to hypoxemia

Question 4

Tropic hormones

Answer 4

• amino acid precursors
• trigger release of other hormones = target endocrine glands
• stimulate growth (hypertrophy/bigger cells or hyperplasia/more cells)
• bind to PNS to increase effects and CNS for neg feedback

Question 5

Penetrant in genetics

Answer 5

-the % that has the genotype which actually expresses the phenotype

Question 6

corpus luteum secretes

Answer 6

progesterone

• no fertilization = LH decreases = stop secreting progesterone and estrogen = endometrium sheds, CL atrophies
• fertilization = zygote secretes hCG which acts as LH to maintain CL = secrete prog and estr through 1st trimester, replaced by placenta which secretes prog and estr on its own; CL atrophies

Question 7

Linked genes

Answer 7

• Law of independent assortment- recomb should be close to 50%
• if it approaches 0% recomb, it’s linked

-linked genes are on same chromosome

Question 8

Edema

Answer 8

swelling/fluid collection

Question 9

What % of blood ends up as filtrate in nephron

Answer 9

20%