Exam 2 Lectures - Bio Evo

Not coding.

The majority of our genome is __________

Horizontal.

____________ gene transfer is when DNA is transmitted from one individual to another unrelated individual.

Coding.

Most of the bacterial genome is __________, meaning it codes for proteins.

Half.

Transposable elements make up about __________ of our genome.

Exome.

The __________ is the portion of our DNA that actually codes for proteins and functional RNAs.

Transduction.

The process of __________ involves a virus infecting a bacterium and inserting its own DNA.

Recombination.

Over time, __________ rate in eukaryotes can be impacted by the genome size.

Single.

The unique feature about viral genomes is that they often code for multiple proteins from a __________ strand of genetic material.

Transformation.

For bacteria, __________ is when free pieces of DNA are taken up and incorporated into their chromosomes.

GC content.

The __________ of the genome influences the stability of the DNA at higher temperatures.

Plateau.

The relationship between genome size and the amount of coding DNA in multicellular organisms is that genome size tends to __________ off.

Spike.

The __________ strand of RNA is heavily studied due to its role in the coronavirus outbreak.

Conjugation

Direct transfer of genetic material between bacteria, often involving plasmids that confer advantageous traits, such as antibiotic resistance.

lower recombination

larger genomes tend to show ____ rates, which can impact evolutionary dynamics.

cellular efficiency, relative abundance of tRNA species

Factors influencing codon usage include ___ and the ___

tRNA

Codon preference exists because the ___ molecules that recognize those preferred codons are more abundant, making translation faster and more efficient

GC

Organisms with high ___ content, particularly certain bacteria, are often associated with environments of higher stability, such as extreme temperatures, due to the increased thermal stability offered by ___ base pairs.

Aploximis

This mode of asexual reproduction allows for the production of offspring without any fertilization taking place. Offspring are typically clones of the parent, which means there is no genetic variation. This can be advantageous in stable environments where the parent's genetic traits are well-suited for survival.

automoxis

Often referred to as "self-mixing," this involves the fusion of proto egg cells within the female reproductive tract. While it can create genetic diversity, it tends to be less significant than the variation produced during sexual reproduction.

chryptomonis

This type of algae is recognized as a high-quality food source, promoting the health and growth of the consuming population.

semidesmis

this lower-quality algae can adversely affect the health and well-being of the organisms that rely on it as a food source, demonstrating how different food quality can influence population dynamics.

isogamy

Organisms with gametes of the same size (e.g., some marine invertebrates, algae).

anisogamy

Most animals exhibit different sized gametes, typically large eggs (females) and small sperm (males).

reduce mobility, disruptive selection

Larger gametes increase survival chances but ____.

This leads to a ____, resulting in two gamete strategies: larger, non-motile eggs vs. smaller, motile sperm.

good gene hypothesis, direct benefits model, handicap principle

explanations for how and why certain traits evolve through sexual selection, but they focus on different mechanisms.

good gene hypothesis

Certain traits indicate high genetic quality (e.g., disease resistance, strength, longevity). By choosing a mate with these traits, an individual ensures their offspring inherit "good genes."

• ex. facial symmetry in humans

direct benefits model

Some traits are favored because they provide the choosing individual with direct benefits (e.g., food, protection, parental care). Instead of just passing down good genes, the mate provides tangible advantages.

handicap principle

Costly traits (ones that are hard to maintain or increase risk, like a large peacock tail or massive antlers) serve as honest signals of fitness. Only the strongest individuals can afford to "waste" energy on these traits, proving their superior genes.

fischerian selection

involves a runaway process in trait exaggeration, where females prefer increasingly extreme male traits, regardless of their survival costs.

intrasexual selection

Competition among males for access to females; males often exhibit traits like large size or armaments (e.g., horns in deer).

polygyny

mating system where one male mates with multiple females, while each female typically mates with only one male

sexual conflict: males want to monopolize multiple females to maximize their reproductive output

polyandry

mating system where one female mates with multiple males, while each male typically mates with only one female

sexual conflict: arises because females benefit from genetic diversity in their offspring, ensuring their eggs are fertilized by the highest quality sperm, and also gain parental care from multiple mates for better protection

sexual conflict

• Occurs when the reproductive interests of males and females differ, leading to strategies like polygyny or polyandry

polygynandry

Multiple males and multiple females form breeding groups, leading to complex mating dynamics.

extra-pair fertilization

refers to the phenomenon where offspring are conceived by a female mating with a male outside her primary pair bond (i.e., a mate other than her social or long-term partner). This occurs when a female mates with a male who is not her primary mate, leading to fertilization by this extra-pair male, allowing genetic variation

wear and tear hypothesis

suggests that over time, the body wears out because of the constant damage caused by everyday use, environmental factors, and stress.

survivorship curves

Represents the proportion of individuals from a cohort that survive across different life stages over time. These curves serve as important visual tools in understanding mortality rates and life expectancy within populations.

type 1

Survivorship curve type: high survival rates in early and middle stages, dropping dramatically in old age

Type 2

Survivorship curve type: constant mortality rates regardless of age

type 3

Survivorship curve type: low survival rates early in life with a higher survival rate for those who make it past a critical age

late-acting

These mutations tend to have a negligible impact since there are fewer individuals alive to express these mutations, resulting in lower visibility in the population's phenotype across generations, less purged by natural selection

early-acting

have a significant impact as they are expressed while a greater number of individuals are alive, allowing these mutations to be passed on and become more common within the population.

lytic viruses

Infect host cells, rapidly replicate their genetic material, produce copies of the virus, and ultimately destroy the host cell in the process. Examples include HIV and SARS-CoV-2 (the virus causing COVID-19).

lysogenic viruses

Incorporate their genetic material into the host cell's DNA, allowing them to remain dormant for extended periods before triggering a lytic cycle. Herpes simplex virus is a notable example of this type.

red queen hypothesis

the constant need to evolve to stay alive because the environment and other species are always changing.

arms race

escalating competition between species, where each tries to out-evolve the other in traits like speed, strength, or defense.