Unit 1
In a certain species, 2n = 60. If one diploid cell in this species undergoes meiosis, the products will be
4 cells, each with 30 chromosomes
Distinguish between homology and analogy.
Homology: structure has a common ancestry (divergent)
Structures may have different functions but share similar underlying structures (e.g. Forelimbs of mammals and birds)
Analogy: structures have similar functions - no shared common ancestry (convergent)
A similar function in different organisms
No shared ancestry or developmental pathway
Evolved independently in different selections due to similar environmental conditions (e.g. Wings of birds and wings of insects)
Salt-water fish and seabirds tend to take in too much salt. Which specific action in their transport epithelium membranes uses ATP to achieve osmotic homeostasis?
Pump out Na+
Define coevolution & what relationship it occurs most with
two participating species each evolved in response to selection by the other one. (most common in mutualistic relationships)
Definition of adhesion vs cohesion.
Adhesion- water sticks to surface/xylem
Cohesion- water sticks to water
Name the main assumptions of Hardy-Weinberg equilibrium. Tell how violating any one of those assumptions would cause the population (gene pool) to evolve and not stay in equilibrium.
1. No mutation
2. Large Populations
3. No gene flow
4. No natural selection
5. Random mating
If assumptions NOT met= MicroEvolution
Which of the following is likely the greatest impact that organisms have ever had on Earth?
Early cyanobacteria released oxygen to Earth's atmosphere during the water-splitting step of photosynthesis.
Name the four tissue types and three specialized cell-cell junctions found in animals.
types of tissue: epithelial, connective, muscle, nerve
cell-cell junctions in animals: tight junctions, desmosomes, gap junctions
What is the rate determined on (give the equation)
rate= births - deaths
Define Density-dependent and give examples
Density-dependent mortality- at greater densities, there’s a greater rate of loss (graphed with reaching K)
Disease
Competition
predation
Which of the following is a distinction between sympatric speciation and allopatric speciation?
allopatric speciation involves a geographic barrier while sympatric does not
Distinguish the three domains of life and the four major groups (”kingdoms”) within the domain Eukarya.
Three domains of life
1. Bacteria
2. Archaea
3. Eurkarya
Protista: Algae and protozoans (mostly unicellular & multicellular)
Fungi: mushrooms, yeasts, molds
Plantae: all plants (mosses, ferns, flowering plants) Multicellular organisms
Animalia: All animals (jellyfish, mammals, and birds)
Once a B cell is activated by binding its specific antigen, it clones into many cells, mostly plasma B cells. How do plasma B cells fight free-floating antigens?
plasma b cells fight free-floating antigens by secreting antibodies into blood/lymph which bind to its specific antigen & marks it for destruction by attracting phagocytes.
Gause’s competitive exclusion principle:
two species with identical niches (exactly the same resources and conditions) cannot coexist indefinitely.
Tell how the anterior pituitary acts as a master control by secreting tropic hormones. How does the hypothalamus signal the anterior pituitary?
The anterior pituitary secretes tropic hormones
hypothalamus: monitors body conditions
serves as a homeostatic control center by stimulating effectors that are not hormones
neurosecretory cells receive nerve information from the brain (neurotransmitters) and secrete hormones into the blood
Using a specific example, explain the process (sequence of changes) of evolution by natural selection for a given trait in a population in a specific environment.
British Peppered Moths
Genetic Variation - the moths had genes for different colors
Change in the environment - the trees became covered in soot
Individuals with certain traits reproduce more - The dark-colored moths reproduce more
Change in allele frequency over time - the moths are now more likely to have alleles for the dark coloring
When a pollen grain nucleus fertilizes an egg nucleus from the same individual plant (self-pollination and self-fertilization), is that the same as asexual reproduction? Why or why not?
NOT asexual because the pollen grain (is a part of the male reproductive) & the egg nucleus (female reproductive). Meaning plant has both male and female reproductive parts (which happens to be on the same plant) = SEXUAL REPRODUCTION
Distinguish the general problem in insulin-dependent (type 1) diabetes mellitus from that in non-insulin-dependent (type 2) diabetes.
type 1 diabetes: insulin-dependent diabetes mellitus
The person cannot produce insulin
type 2 diabetes: non-insulin- diabetes mellitus
Insulin receptors are not effective
What is the relationship between changes in atmospheric CO2 levels and ocean pH levels?
Ocean acidification = aquatic twin of high atmospheric CO2
There is a relationship between increased CO2 levels in the atmosphere and the pH of water. The pH of the water goes down, getting more acidic.
Describe the Boolean operators “AND” and “OR” in setting up a search
“OR”: connects the alternate terms we have generated, so that our database will produce results that contain at least one of the terms in the list, not necessarily all.
“AND”: another function that we are using in our string. The function of “AND” is to only call results that use both terms.
An example is: maggot fly AND speciation
In a population of mice, 91% of the individuals show the dominant trait T (inherited as complete dominance). What percent of the individuals are heterozygotes Tt? Show the answer (on the line), and write one Hardy-Weinberg equation that you used.
q2 = 0.09 p + q = 1 so q = 0.3 and p = 0.7 p2 + 2pq + q2 = 1 2pq=0.42
_answer___42__%
The fruit develops from what flower part? What is the evolved function of fruit?
Fruit develops from the ovary wall
The evolved function of fruit: provide nutrition for animals that disperse seeds; an adaptive seed dispersal mechanism that allows animals to disperse seeds
State three specific ways the structure of the lung alveolus epithelium is adapted for its function to maximize gas exchange by diffusion.
Large surface area, short diffusion distance (thin membranes), alveolus membrane near the blood capillaries; steep gradient (breathing in fresh air, blood carries away oxygenated blood; hemoglobin binds) [note: alveoli do not have microvilli]
Name three major threats to biodiversity today, and give a specific example of each.
Habitat loss and habitat degradation (deforestation)
Spread of non-native, invasive species (introduction of mongooses on the Virgin Island and Hawaii)
Over-harvesting and overpopulation (Ivory trade of elephant trunks)
You are studying a population of beetles of size 3000 (N0). During a one-month period, you record 600 births and 300 deaths in this population. Estimate b, d, and r for that first month (What would N1 be?) and a project that population’s size (N2) after a second month at the same rates.
N1 = 3300, N2 = 3630