Name a pro and con of asexual reproduction.
Pros: can retain favorable combinations of genes, relatively rapid (don't need to find another individuals to reproduce with, and therefore energy-efficient)
Cons: little genetic diversity, little adaptations, diseases can greatly affect population
What does the sperm contribute to the zygote?
A nucleus and a centriole
Within this structure of the nephron, blood is exposed to high pressure and filtered.
Glomerulus
What collects the filtrate created by the glomerulus?
In a vegetative state, a plant's bud can develop into ____ and in the reproductive state, a bud can develop into a _____.
Branch, flower
_______ is a mineral element needed for protein synthesis and ______ is a mineral element needed for nucleic acids.
A) S, Na
B) K, P
C) P, S
D) S, P
E) Na, P
D) S, P
What mineral element is necessary for osmoregulation?
Potassium, K
What can be exchanged through placental membranes?
A) Nutrients
B) CO2
C) Blood
D) O2
E) A and B
F) B and D
G) A, B, and D
H) All of the above
G) A, B, and D - nutrients and gasses can be exchanged through the placenta.
Along with limiting water loss, this extraembryonic membrane facilitates gas exchange. It sits beneath the egg shell.
Chorion
What are the other 3 extraembryonic membranes and their functions?
1) Yolk sac - encloses yolk, which provides developing embryo with nutrients
2) Allantois - stores metabolic waste
3) Amnion - surrounds embryo and provides shock absorption/protection
What happened to body fluid osmolarity during the colonization of freshwater in animal evolutionary history?
Lower body fluid osmolarity
Which feature is the best one to use if you are trying to determine if the cylindrical portion of a plant was the stem and not the root?
A) the presence of axillary buds
B) vertical growth
C) primary growth at one tip
D) serving as s storage organ
E) growing up the ground
A) presence of axillary buds
Blocking the synthesis of what hormone will slow down fruit ripening?
Ethylene
What somatic cell responds to FSH and contributes to sperm formation by releasing androgen binding protein?
Sertoli/nurse cells
ABP binds with what hormone to stimulate spermatogenesis?
In animals with moderate yolk, cells in the animal hemisphere have [MORE/LESS] cells that [LARGER/SMALLER] in size compared to those in the vegetal hemisphere.
More; Smaller
Regions with yolk (vegetable hemisphere)--> slower division, fewer, larger cells
Regions without yolk (animal hemisphere) → faster division, more, smaller cells
Osmotic [REGULATORS/CONFORMERS] maintain an internal osmotic pressure through active transport. Because of this, they [CAN/CAN'T] tolerate a range of salinities.
regulators; can
List the order of layers a water molecule would pass through to get to the center of a stem.
Cortex, Endodermis, Epidermis, Pericycle, Xylem
Epidermis --> Cortex --> Endodermis --> Pericycle --> Xylem
Apoplastic vs symplastic movement of water?
List all of the legumes that have a symbiotic relationship with a nitrogen-fixing bacteria called Rhizobium.
Alfalfa, beans, peas, clover
Embryonic diapause is a process that can decouple embryonic development and __________.
Fertilization - why would adjusting when the egg is fertilized be beneficial?
This is a vertebrate limb morphogen that creates a Zone of Polarizing Activity.
Sonic Hedgehog - high concentrations of this stimulates the development of what?
List a pro and con of group living
Pros: increases success at finding dark habitats to hide in (fish schools); flocks can detect predators faster (more eyes on the watch)
Cons: more noticeable to predators; greater risk of disease transmission; higher cost associated with competition and resources (more mouths to feed)
Name 3 functions of the root cap.
1) detects gravity (gravitropism)
2) protects the RAM
3) produces mucus/lubricant
4) produces border cells
Does the root cap undergo continuous cell division for primary root growth?
When gibberellin binds to its receptor, what happens in order for a-amylase to be produced?
A) Protein pumps in the plasma membrane are activated
B) A protein kinase cascade is initiated
C) Certain gene repressors in the nucleus are activated
D) Certain gene repressors in the nucleus are inactivated
E) None of the above
D) Certain gene repressors in the nucleus are inactivated
Describe the two types of blocks against polyspermy.
Fast:
- Rapid depolarization across membrane
- Ovum’s membrane becomes positive → blocks any more positively-charged sperm from entering (like repels like)
Slow:
- Exocytosis of Ca2+ from egg's sarcoplasmic reticulum --> triggers release of cortical granules
- Cortical granules - (1) release enzymes the dissolve bonds b/w vitelline envelope and cell membrane and (2) absorbs water via osmosis to cause swelling b/w vitelline and egg membrane --> vitelline envelope moves outwards and hardens into the fertilization envelope
Describe neurulation and the fates of each of the 3 germ layers.
Describe the difference(s) between the two types of nephrons.
1) Cortical - short loops; don’t go far into medulla → not a lot of water leaving ducts → less water reabsorption/conservation --> low urine concentration (more diluted urine)
2) Juxtamedullary - longer loops; run deeper into medulla --> surrounded by more extracellular solutes --> more water leaving the ducts --> more water reabsorption/conservation --> high urine concentration (less diluted urine)
Explain how phloem gets from a source to a sink, and make sure to mention phloem loading, water potential, and solute potential in your explanation.
1) A source (such as a mesophyll cell) has accumulated a lot of sugar/phloem sap. The pressure from this build up of sugar generates the force that moves/loads phloem sap into sieve elements.
2) Loading of sieve elements with high concentrations of sugar REDUCES SOLUTE POTENTIAL (Ys), because adding more solutes makes Ys more negative.
3) Because Ys is decreasing in the sieve elements, so is water potential (Y).
4) Water likes to move from high to low water potential, so water from neighboring xylem is going to move the phloem's sieve elements (move towards lower Y), pushing the sugar to the sink.
Which of the following does not rely on ATP-driven proton pumps?
A) Polar transport of the auxin hormone
B) Opening stomata
C) Apoplastic phloem loading
D) Nodule formation
E) All of the above rely on proton pumps
D) Nodule formation