Exam Review Flashcards
Four major groups of plants
BRYOPHYTE:
dominant part of life cylce is Gametophyte
PTERIDIOPHYTE
dominant part of life cylce is Sporophyte
GYMNOSPERMS
dominant part of life cylce is Sporophyte
ANGIOSPERMS
dominant part of life cylce is sporophyte
recognize fungi names
(Myco=fungi)
Species concepts
BIOLOGICAL
defines a species as members of populations that actually or potentially interbreed in nature, not according to similarity of appearance.
PHYLOGENETIC:
The concept of a species as an irreducible group whose members are descended from a common ancestor and who all possess a combination of certain defining, or derived, traits
MORPHOLOGICAL
Organisms are classified in the same species if they appear identical by morphological (anatomical) criteria.
prokaryote vs eukaryote
Eukaryotic cells contain membrane-bound organelles, such as the nucleus
Prokaryotic cells do not contain membrane bound organells such as a nucleas
Dichotomous Key
Dichotomous Key: tool that allows the user to determine the identity of items in the natural world that consist of a series of choices that lead the user to the correct name of a given item.
explain phylogenetic tree
PHYLOGENETIC TREE:
• A diagram depicting the evolutionary relationships between different species or groups (previously called cladogram)
• Phylogenetic trees focus on categories based on common ancestors (evolutions)
CLADES:
• A taxonomic group that includes a single common ancestor and all its descendants. Each clade on phylogenetic tree can be thought of as a branch on the tree of life
assess the impact of human intervention on biodiversity
habitat fragmentation
over fishing
effect of climate change on ecosystems
- For instance, warming could force species to migrate to higher latitudes or higher elevations where temperatures are more conducive to their survival.
- -as sea level rises, saltwater intrusion into a freshwater system may force some key species to relocate or die, thus removing predators or prey that were critical in the existing food chain.
what causes/impacts biodiverity
biodiversity larger with population size and with more species
meiosis
• Sexual reproduction involves 2 parents • Meiosis the formation of genetically diverse gametes (sex cells) • Hereditary material is exchanged (mixed and transferred) • Each species had a specific number of chromosomes STAGES: interphase prophase 1 metaphase 1 anaphase 1 telophase 1 prophase 2 metaphase 2 anaphase 2 telophase 2
mitosis
The purpose of mitosis is cell regeneration, growth, and asexual reproduction STAGES: prophase metaphase anaphase telophase
independent assortment & law of segregation
INDEPENDENT ASSORTMENT:
—principle that genes are inherited independently of one another
LAW OF SEGREGATION:
—each pair of alleles segregates independently of the other pairs of alleles during gamete formation.
—In diploid organisms, chromosome pairs (and their alleles) are separated into individual gametes (eggs or sperm) to transmit genetic information to offspring.
mono-hybrid cross
- -a hybrid that is heterozygous (one is dominant and one is recessive) with respect to a specified gene.
- -always yields a 3:1 ratio (dominant: recessive)
- -TT x tt
blood type crosses
Type A= ia, ia / i, ia
Type B= ib,ib / i, ib
Type O = i, ii
viruses
LYTIC
• Viral DNA hi jacks the ribosomes of host
• Ribosomes used to make and assemble duplicates or original virus (mass produced)
• Once they reach certain amount, viral cell lyse (explode) the host cell and spread out to infect other cells
○ This can be entered from lysogenic cycle
○ If this continues, the virus will kill host organism
LYSOGENIC
• Viral DNA integrates into host DNA and remains silent
• Whenever host DNA replicates, viral DNA replicates
• Allows the virus to replicate and pass to other organism without detection or immediately harming host
Darwin’s main points
A species is a population of organisms that interbreeds and has fertile offspring.
Living organisms have descended with modifications from species that lived before them.
Natural selection explains how this evolution has happened:
More organisms are produced than can survive because of limited resources.
Organisms struggle for the necessities of life; there is competition for resource.
Individuals within a population vary in their traits; some of these traits are heritable – passed on to offspring.
Some variants are better adapted to survive and reproduce under local conditions than others.
Better-adapted individuals (the “fit enough”) are more likely to survive and reproduce, thereby passing on copies of their genes to the next generation.
Species whose individuals are best adapted survive; others become extinct.
importance/impact of genetic diversity
- -when a population of an organism contains a large gene pool the group has a greater chance of surviving and flourishing than a population with limited genetic variability.
- -genetic diversity strengthens a population by increasing the likelihood that at least some individuals will be able to survive major disturbances, and by making the group less susceptible to inherited disorders.
Genetic Drift
variation in the relative frequency of different genotypes in a small population, owing to the chance disappearance of particular genes as individuals die or do not reproduce.
Gene Flow
the natural transfer of genes from one population into the genetic makeup of another population through hybridization and interbreeding
describe an evolutionary scenario
b
Artificial selection
PRO
-It will allow needed traits to be produced quickly and effectively.
-It creates the potential for added profitability.
-can enhance the quality of what is being created.
CON:
—less diversity
—decreased quality of life
Speciation Mechanism
ALLOPATRIC:
of animals or plants, especially of related species or populations) occurring in separate non-overlapping geographical areas
SYMPATRIC:
(of animals or plants, especially of related species or populations) occurring within the same geographical area; overlapping in distribution.
SEXUAL SELECTION:
natural selection arising through preference by one sex for certain characteristics in individuals of the other sex.
Reproductive Barriers
PRE-ZYGOTIC
-prevent mating or fertilization between different species
-temporal isolation (species reproduce at different times)
-habitat isolation (species remain isolated because they breed in different habitats.)
-behavioral isolation (differences in mating rituals)
-mechanic isolation (physically unable to reproduce)
POST-ZYGOTIC
-reproductive barrier that operates should interspecies mating occur and form hybrid zygotes
-hybrid inviability ( offspring (called a hybrid) does not survive)
-hybrid sterility (hybrid is infertile)
-hybrid breakdown (he first-generation hybrids are viable and fertile, but when they mate the offspring are feeble and sterile)
Allele, diploid/haploid
ALLELE: one of two or more alternative forms of a gene that arise by mutation and are found at the same place on a chromosome
DIPLOID:
of a cell or nucleus) containing two complete sets of chromosomes, one from each parent
HAPLOID:
pertaining to a single set of chromosomes.
