bio Flashcards
facultatively sexual
can reproduce sexually (through pollination) or asexually (through vegetative propagation)
asexual reproduction
bacteria and archaea
produce exact copy of self, no genetic exchange of information
evolve through mutation and horizontal genetic exchange from other organisms
parthenogenesis
type of aasexual reproduction reproduction where females produce offspring
unfertilized diploid egg (clones, no meiosis)
dna in haploid eggs replicates (haploid to diploid, not clone)
dioecious
every organism is either a male or a female with spearate reproductive parts, but cannot be both (such as Ginkgo trees, humans)
monoecious
separate male and female sex organs in the same individual but in different structures such as plants with different flowers for male or female parts
hermaphrodite
sex organs occur together, simultaneously acting as amale and female, such as snails and slugs
sequential monoecy
sex change occurs at some point in development
ex. all born female, but largest member in group changes to male. when that male dies, the next largest female changes to male
Protandry
male turned female
Protogyny
female turned male
benefits of sexual reproduction
speeds up evolution (increases beneficial mutations in individuals, and decreases harmful mutations more quickly)
Decreases the likelihood of extinction (more variety)
cost of meiosis
only passing down 50% of genome to next generation, while asexual individuals pass 100% of genome
cost of making males
females only need genetic material to reproduce. Makes only contribute sperm, but -50% of progency are male. Only a few males are needed, however to reproduce.
Benefits of sexual reproduction
sexual reproducion creates some offspring that have fewer mutations than either parents, while asexual will carry all mutations of the parent cell
sexual dimorphism
refers to differences in traits between males and females
theory of endosymbiossis
explains how ancestral prokaryote led to formation of ancestral eukaryotes through uptake of aerobic bacteria and subsequently cyanobacteria
ecological intelligence hypothesis
having a big brain allowed them to communicate, use tools, plan how to escape from predators and get food in order to survive
social intelligene hyhpothesis
to live with other members of our species we need to be competitive and cooperative
cultural intelligence hypothesis
the social learning togethr of ecological relevant skills to cooperativey hunt and build shelters
mating mind hypothesis
word play, humour and art leads to mating success
exponential growth model
human population currently (dramatic increaes)
r= birth rate- death rate
population growth rate = r x N (population size)
density dependent factors
depends on how large/small the population is the impact
density independent factors
population size doesnt matter, smae influence no matter how many organisms are present
fecundity
potential reproductive output
generation time
average time between two generations
