Exam 2 Flashcards
Xylem
- transports water and minerals from roots to shoots
- Content: Waters and minerals
- Speed: faster
- Direction: up
- Purpose: Deliver water for turgid pressure, maintain photosynthesis
Phloem
- Transports photosynthates from their sources (leaves, shoots, etc.) to the roots
- Content: Photosynthates/sugar
- Speed: slow
- Direction: Multidirectional
- Purpose: sugar used in energy and ATP production, fuels respiration
Apoplast
-extracellular space, outside of cell membrane
Symplast
-all cytoplasm in the plant (including plasmodesmata)
Water Potential
- The pressure on water to move
- The sum of the solute potential and the pressure potential
- Water moves from areas with high water potential to areas with low water potential
Solute Potential
- Directly proportional to the molarity of a solution (is always negative)
- Increased absolute solute potential has a negative effect on water potential
Pressure Potential
-Physical pressure on a solution (can be positive or negative)
Bulk Flow
-Movement of water throughout a plant in response to negative pressure
Epidermal Cells
- The first barrier for water intake in roots
- Sometimes involving aquaporins
Mycorrhizae
- Mutual relationship between plant roots and fungi
- Fungi help roots gather more water and minerals by increasing surface area
Endoderm Cells
-Serve as a final checkpoint for the selective passage of minerals from the cortex into the vascular cylinder
Casparian Strip
-Waxy barrier that determines what enters the Xylem, in the Steele
Root Pressure in Transpiration
- Pushing
- Depends on pumping ions into Xylem
- Caused by increased pressure and water potential in the roots
- Aids in transport of Xylem Sap
Cohesion-Tension in Transpiration
- Pulling
- Depends on transpiration and hydrogen bonding
- Transpiration in plant leaves creates negative water potential in the shoots
- **use its cohesive properties to be pulled up
Explain how cohesion-tension arises in leaves, including the role of guard cells and negative pressure at the intra-leaf air-water interface
- Cohesion-tension occurs in leaves due to transpiration and its negating effect on water potential in the leaves
- Guard cells= responsible for opening/closing the stomata, release water, leading to transpiration
Given information about solute and pressure potential, predict whether water will move into or out of a plant cell
- Increased solute potential lessens water potential
- Positive pressure potential increases water potential
- Negative pressure potential decreases water potential.
Gastrovascular Cavity
- Coelom-like
- Involves no tissue
- Lets what freely enter/exit
Open Circulatory System
- Uses hemolymph
- Continuous w/ interstitial fluid
- Hemolymph can be used for movement
- Not efficient for maintaining high Oxygen levels
- Unable to support big animals w/ high metabolism or warm-blooded animals
- Grasshoppers, and other insects
Closed Circulatory System
- Blood does not come into direct contact with interstitial fluids
- Exchange happens across plasma membrane
- Network must be very large to reach every cell
- Good for maintaining high Oxygen levels
- Good for animals with high metabolism and warm-blood
- Ex:Earthworms, humans, etc.
- Types: single, double 3 chamber, double 4 chamber
Single Circulation
- Atrium- pumps blood from body into heart
- Ventricle- pumps blood from heart to body
- Artery- carries blood away from the heart
- Vein- carries blood towards the heart
- Capillaries
- **Plasma membranes are smaller w/ thinner membranes
- **Where exchange happens
- Moving body helps move blood to heart
Double Circulation
-Heart pumps blood to lungs and body
• 3 chambers in ectotherms
• 4 chambers in endotherms
• Constant need for Oxygen
Capillary/ Capillary Bed
- Microscopic vessels with porous walls
- Network of capillaries where exchange happens across the membrane of vessels and cells
Pulmonary Artery
-Transports deoxygenated blood from right ventricle to lungs
Pulmonary Vein
-Transports oxygenated blood from lungs to left atrium
Aorta
-Pumps oxygenated blood from heart to body
Superior Vena Cava
-Pumps deoxygenated blood from head/arms to heart
Inferior Vena Cava
-Pumps deoxygenated blood from legs/torso to heart
Pathway of blood circulation in closed double circulation 4 chambers
- Starting from capillary beds, deoxygenated blood travels through the inferior vena cava (if coming from legs and torso) or the superior vena cava (if coming from the head and arms) to the right atrium.
- Blood moves from right atrium into right ventricle, where it is pumped through the pulmonary arteries, into the lungs.
- Pulmonary vein –>Newly oxygenated blood travels to the left atrium and then the left ventricle where it is pushed through the aorta into the capillary beds
- Repeat
Compare and Contrast Artery, Vein, Capillary
- Artery
- *S: 3 layers, relatively thick
- *F:No exchange, absorbs the most BP
- Vein
- *S: 3 layers, thinner than artery
- *F: No exchange, less BP than artery
- Capillary
- *S: 2 layers, thin basal lamina
- *F: Exchange w/ interstitial fluid
Partial Pressure
- Pressure exerted by a gas in a mix of gases
- proportional to ratio of gas composition
Water as respiratory media
- Lower temperature and lower salinity lead to higher level of Oxygen levels in water
- More viscous than air
Air as respiratory media
- Higher concentration of O2 than water
- Easy to move
- Con- need to stay moist
Trachea
-Guides bulk of air from outside to bronchia
Bronchia
-Major air passageways that break apart from trachea
Bronchioles
-Break apart from bronchia
Alveoli
- Air sacs with thin membranes
- where exchange of Oxygen with capillaries occurs
Mucus
-Remove unwanted particulates from air before it reaches alveoli
Cilia
-Remove unwanted particulates from mucus
Surfactants
-Liquid surrounding alveoli that prevent them from collapsing, by reducing surface tension
Gametophyte
-Multicellular haploid, produced by mitosis to form gametes (egg or sperm)
Sporophyte
-Multicellular diploid produced by meiosis to form spores
Pollen
-Formed by Angiosperms for reproductive processes; hermaphroditic behavior
Ovule
-Is fertilized into a seed (egg cell equivalent in plants), by another plant’s sperm
Cone
-Creates pollen (male gametophyte of seeds); produced by gymnosperms
Flower
-Formed by Angiosperms to contain pollen; male gametophyte of seed plants
Moss
- Nonvascular plants
- Ex: Bryopsida
- Hapolid dominant (gametophytes)
- Larger gametophyte, free-living
Gymnosperm
- Produce both female and male cones
- Male cone produces pollen which goes to fertilize the female cones’ eggs
- Ex: Blue spurce
- Diploid dominant (sporophytes)
- Gametophyte= miniature, inside cones
Angiosperm
- Plants that produce flowers and animal pollination to reproduce
- Ex: Pineapple
- Diploid dominant (sporophytes)
- Minature gametophytes, inside flowers
Sexual Reproduction
- Combining genetic material (created through meiosis) from separate sexes to create genetically unique offspring
- Pro: diversity (recombination of genetic material)–> evolution and natural selection
- Con: slower population growth, find mate, stds, loss of well-adapted genotype, two-fold cost
Asexual Reproduction
-Reproducing through mitosis to create genetically identical offspring
Sperm
-Male gamete
Egg
-Female gamete
Hermaphroditism
- A single individual capable of producing sperm and eggs simultaneously
- Pro: Easy to find mates
- Con: no specialization/ sexual dimorphism
Sequential Hermaphroditism
- A single individual capable of producing sperm and eggs, but not at the same time
- Pro:Easy to find mates, can have specialization
- Con: cost of switching
Ovulation
-The release of mature eggs
Gonad
-Organs that produce gametes
Where does Spermatogenesis occur?
- Seminiferous tubules
- *Move outer to middle
- Sperm development in Epididymis
- *Acrosome= head of sperm, communication
- *Lots of mitochondria
When does Spermatogenesis occur?
- Post adolescence until death
- Constant production (millions per day)
How does Spermatogenesis occur?
- Regular meiosis
- Produce 4 haploid sperm per spermatogonium
Where does Oogenesis occur?
- Ovaries
- Primary oocytes at birth
When does Oogenesis occur?
- Post adolescence to menopause
- Periodic (about one egg a month when not pregnant)
- No ovulation during pregnancy and/or lactation
How does Oogenesis occur?
- If done to completion, each oocyte becomes 2 polar bodies and an egg cell (one polar body per phase of meiosis)
- Meiosis 1 for ovulation and Meiosis II occurs post fertilization
- Absence of sperm fertilization precludes second stage
Development
-the process of formation, post-fertilization
Cell-Lineage Based Development
- Occurs in animals
- Some stem cells have limited scope of potential for specialization
- i.e. stem cell can only become a nerve cell or muscle cell
Position Based Development
- Occurs in plants
- Cells take cues from neighbors to choose specialization
- i.e. cell divides into two new cells, surrounded by Xylem cells, causing them to specialize as Xylem Cells
Low CO2, High O2
- In the lungs, right after inhalation
- In the blood, after oxygenation (passing through the capillary beds in the lungs)
- In the interstitial fluid, right after receiving Oxygen and giving Carbon Dioxide through an exchange with blood
High CO2, Low O2
- In the lungs, right before exhalation
- In the blood, after trading Oxygen for Carbon dioxide with interstitial fluid
- In the interstitial fluid, after depleting oxygen
Two-fold Cost of Sexual Reproduction
- Reproduce at the rate of egg production
- **slow repopulation for sexually produced organisms, in comparison to asexually produced, genetically-identical organisms
- Offspring inherits half of previous generation’s genetic material
Fern
- Ex: ostrich fern
- Diploid dominant (sporophytes)
- Small gametophytes, freeliving on or in soil
External Fertilization
- Requires a wet environment
- Large # of gametes
- **dilution effect
- **abiotic environment
- **Predation (predators eat gametes)
- High level of coordination btwn individuals
- **spawning
- Little to no parental care
Internal Fertilization
- Wet environment inside body
- Smaller number of gametes produced
- *concentrated in smaller space
- *environment less variable
- *protected from predators
- Need for coordination is less
- Often greater parental care
Parental Care in Internal fertilization
-Pro: produce fewer games
**saves resources
**individual offspring more likely to survive
Cons: costly
**Limits number of offspring produced
**More care= fewer total offspring
Fission
-One adult dividing into 2 equally-sized complete adults
Fragmentation
- Breaking into pieces and regeneration of missing parts
- Ex: starfish
Parthenogenesis
- Reproducing from an unfertilized egg
- Ex: dandelions
Asexual reproduction in plants
- Hermaphroditism
2. Sexually
