Bio Exam 2 (1114 osu) - Stephen Chordas

Species

Word literally means “kind,” both singular and plural. New species = variants become isolated. Populations evolve not individuals.

Morphological species concept

Similar in body shape and external features

Ecological species concept

How a group of organisms interact with their environment

Phylogenic species concept

Smallest identifiable group that shares a common ancestor

Biological species concept

Inter-breeding populations that are reproductively isolated. interbreed and produce fertile offspring.

Prezygotic (reproductive isolation)

Prevents mating attempts or fertilization. before the gametes fertilize to create a zygote. This can be any of five types of isolation mechanisms that keep gametes from fertilizing including spatial, temporal, behavioral, mechanical, and gametic

Geographic isolation

Populations are physically separated by barriers (mountains, rivers, distance).

Mechanical isolation

Reproductive structures don’t fit or function together.

Gametic isolation

Sperm and egg can’t fuse even if mating occurs.

Behavioral isolation

Signals/songs, rituals (like light display), or markings don’t match, so mating doesn’t happen.

Temporal isolation

Species breed at different times, so they never mate. Different times of year (spring vs fall flowers) or during different years.

Ecological / habitat isolation

Species use different habitats within the same area and don’t encounter each other. Ex. In trees vs on cliff land snails.

Postzygotic (reproductive isolation)

Allow mating and fertilization but prevent viable or fertile offspring

Hybrid infertility

Mating occurs and offspring produced but offspring is sterile. This postzygotic reproductive barrier stops gene flow between populations, ensuring that each species remains genetically distinct.

Hybrid inviability

Hybrid inviability is a post-zygotic barrier, which reduces a hybrid's capacity to mature into a healthy, fit adult.

Allopatric

Gene flow is interrupted due to geographic isolation. Fairly common.

Sympatric

No geographic isolation. Gene flow limited by polyploidy (3+ sets of chromosomes), habitat differentiation, or sexual selection. Common in plants, less so in animals.

Cichlids are an example of

2 species of the genus Pundamilia. A type of fish with different color patterns so they don’t mate. Behavioral isolation/sexual selection.

Polyploidy as a new species in a single generation

Chromosomal make-up changes from parent to offspring. A chromosome‑number change creates a new species immediately because the new polyploid can only mate with others like itself. Common in plants not in animals.

Fitness

The ability of an individual to produce viable offspring relative to others of the same species

Natural selection

Individuals that are best adapted to their environment, will be best (most) capable of surviving to reproductive age AND leaving offspring.

Selected for (natural selection)

A trait that increases survival or reproduction in a given environment.

Selected against (natural selection)

A trait that reduces survival or reproduction.

Selective pressures

Selective pressures are environmental factors that influence which traits are selected for or against.

Survival of the fittest

Individuals best adapted to their environment, who survive AND leave surviving offspring.

Artificial selection

Restricting to only those individuals with the desired characteristics. Ex. Pure dog breeds.

Directional selection

A shift in allele frequencies in a single constant direction, changes from resistance

normal distribution

up then down

skewed distribution

most common is either right or left

bimodal distribution

2 humps (2 normals together)

An insect that exhibits resistance to a pesticide…

A)  Developed the resistance in    response to the pesticide

B)  Mutated to become resistant    when exposed to the pesticide

C)  Inherited the gene(s) that made    it resistant to the pesticide

D)  Is less likely to pass on the    allele to the next generation

C)  Inherited the gene(s) that made    it resistant to the pesticide

Less common phenotype =

More likely to survive + reproduce

Phenotype fitness is ____ dependent

Concentration

Isaac lea

Geologist studied fresh water shells. thought different shape meant different species, however, the clams were just different sexes, if he opened them, he would see the different shape was due to different reproductive processes.

How long does the average fruit fly live?

30 days

Can fruit flies become starvation resistant

Yes

3 habitats with fruits produced on average every

   1 - 18-21 hours        2 - 23.5-27 hours        3 - 5 Days

Predict which option best matches a population’s chance of long term survival if placed in the given habitats

   A) A habitat 1 only; B habitat 2 only; C habitat 3 only

   B) A habitats 1 & 2 ; B habitats 1 & 2 ; C habitat 3 only  

   C) A habitat 1 only; B habitats 2 & 3; C habitat 3 only

   D) A habitat 1 only; B habitats 1 & 2; C any habitat

   E) A habitat 2 only; B habitats 1 & 2; C habitat 3 only

D

Sexual selection

Eggs are larger, require more energy to produce. Sperm are the opposite. Maternal investment to offspring is usually higher than paternal.

Intersexual selection

Mate choice: usually females: often results in extravagant male characteristics

Intrasexual selection

Usually males: competition between members of the same sex. Displays/ agresssions, territory stance.

Sexual dimorphism

Different characteristics and/or courtship between males and females

Epioblasma

genus of North American freshwater mussels (family Unionidae) that live in rivers and streams.

Plants 2 basic parts

Shoots and roots

2 types of roots

Tap and fibrous

Tap root

One central primary root (think, deep root) usually with few lateral roots. Ex. Carrot.

Fibrous roots

Lateral roots: all about the same size/spread laterally - not usually deep.

Shoots

Everything above the area the plant is growing. Consists of stem, branches, flowers, leaves and other structures. Grow only at tips and ends.

Four functions of shoots

Reproduction, photosynthesis, spread of the plant, distribution.

Xylem

A plant vascular tissue that conducts water and ions from roots to shoots

Phloem

A plant vascular tissue that conducts sugars between roots and shoots

Surface area to volume ratio (how to find)

Divide surface area by the volume of the structure

Pollen

Male reproductive cell produced on male reproductive structures (stamen)

Pollination

Any process that transfers pollen to the female reproductive structure (carpel)

What is pollination usually accomplished by? (Name 4)

Insects, bats, wind, water currents

Many plants have both male and female reproductive structures. What is each called?

Male = stamen. Female = carpel.

Monocot

Monocots (monocotyledons) are flowering plants whose seeds contain one cotyledon (one embryonic seed leaf).

• 1 cotyledon

• Parallel leaf veins

• Flower parts in multiples of 3

• Fibrous (adventitious) root system

• Scattered vascular bundles in the stem

Eudicot

Eudicots (“true dicots”) are flowering plants whose seeds contain two cotyledons and whose pollen has three grooves (tricolpate pollen).

• 2 cotyledons

• Net‑like (reticulate) leaf venation

• Flower parts in multiples of 4 or 5

• Taproot system

• Vascular bundles arranged in a ring in the stem

Gymnosperm

A vascular seed plant that produces “naked seeds” — meaning the seeds are not enclosed in an ovary or fruit. Instead, the seeds develop exposed on cone scales or similar structures.

Annuals

Plants that complete their life cycle in a single growing season

Biennials

Plants that complete their life cycle in two growing seasons

Perennials

Plants that continue to grow and reproduce after that season

Toxicodendron genus

Genus that contains poison ivy, oak, sumac

Uroshiol (you Rho SHEE ol)

Oil in plant tissue, oil is water soluble, stable, sticky.

*Oil causes itchy rash in some

Magnification

Ratio of the size of the image to the size of the object

Resolving power

Ability of an optical system to distinguish between two objects that are very close together

Microscope rule

Objects closer than ½ of the source wavelength can not be resolved

Light microscopes nm

400-700 nm

Wavelength

The distance between 2 corresponding points on 2 adjacent waves (measured in nanometers).

Nanometer nm

One billionth of a meter

MP

Magnified 32 times

DPI

Resolution. Used for printers. Dots per inch.

1 megapixel is

1 million pixels

Magnification

ratio of the size of the image to the size of the object

Resolving power

ability of an optical system

Stereo microscope

Max magnification is ~250 X. White light as radiation source. Larger working distance.

Compound microscope

Max magnification is ~1,500 X. White light as a radiation source. Smaller working distance.

Two types of electron microscopes

Transmission Electron microscope, Scanning electron microscope.

Transmission electron microscope (TEM)

Samples must be cut very, very thin. (1000th of a piece of paper). Can see internal details.

Scanning electron microscope (SEM)

Whole samples can be used. Ability to see external details.