Protists & Eukaryotes 1
Definition of a protist
Any eukaryote that is not a plant, animal, or fungi
Why it was adaptive for the larger host cell to keep the engulfed cell alive rather than digesting it according to the endosymbiotic theory
The engulfed cell provided the host cell with adenosine triphosphate (ATP)
The most direct ancestors of land plants.
Green algae
The function of stomata in land plants
Able to open and close to allow gas exchange and decrease water loss.
The stage in alternation of generations that is diploid and what it produces, as well as the stage that is haploid and what it produces.
Diploid: Sporophyte, spores
Haploid: Gametophyte, gametes
Why dinoflagellate blooms can be harmful to humans.
People can get paralytic shellfish poisoning from eating shellfish that were in a dinoflagellate bloom
The difference between meiosis and mitosis, and which was an evolutionary novelty in protists.
Meiosis: Sexual, genetically different offspring, evolutionary novelty
Mitosis: Asexual, genetically identical offspring
Why the first land plants are speculated to have a low, sprawling growth habit.
No structural support to stand up straight in air.
Plant reproductive structure that allows sperm to be transported in the absence of water.
Pollen
Why seeds are more evolutionarily advantageous than spores.
Seeds contain nutrients and a protective coat for the embryo so that they can be dispersed away from the parent plant.
Aquatic protist producers that create silica shells.
Diatoms
Protist mode of locomotion characteristic of amoebozoa.
Pseudopodia
Definition of endosymbiosis, as well as all five pieces of evidence that support the theory of endosymbiosis.
Endosymbiosis is the theory that organelles in eukaryotic cells (mitochondria and chloroplasts) originated from the cell engulfing a prokaryote/bacteria.
1. Similar size as bacteria
2. Contains circular DNA
3. Have own ribosomes to make proteins
4. Replicate by binary fission
5. Double membranes
The difference between homospory and heterospory, and when did land plants switch from homosporous to heterosporous on the plant phylogenetic tree?
Homospory: Produce a single type of spore that is capable of making both sperm and eggs
Heterospory: Male and female spores (microsporangia and megasporangia)
Heterospory evolved in seed plants
The difference between a primary attractant and a secondary attractant in flowers.
Primary attractants: Rewards.. food, shelter, other needed materials
Secondary attractants: Cues.. scents, visual cues (color, shape)
Three nutritional modes of protists, how they are different from one another, and which was an evolutionary novelty of protists.
Absorption: nutrients taken up through the plasma membrane
Ingestion: food is engulfed, evolutionary novelty
Photosynthesis: use of chloroplasts to convert sunlight into energy
The three types of locomotive diversity amongst protists and how they are different from one another.
Cilia: tiny hairs that allow the cell to move in a wave-like motion
Pseudopodia: Projections of the cell membrane that allow for movement
Flagella: hair-like structure that extends from part of the eukaryote to help them “swim”
What liverworts, hornworts, and mosses (collectively known as bryophytes) have in common besides not having vascular tissue. (hint: related to reproduction)
They are tied to water for reproduction.
Function of gametangia, name of female & male part, and why it was evolutionarily advantageous.
Produces gametes in plants. Female: archegonia, male: antheridia. Allows sperm and eggs to not be separated in reproduction, increasing the chances of fertilization. Also protects from drying and damage.
Two evolutionary adaptations of angiosperms and why they were beneficial.
Flowers: attracts pollinators for more efficient/targeted pollen transfer
Fruits: encloses and protects seeds, dispersal by animals
Two morphological innovations of protists and why they were adaptive.
Compartmentalization of organelles: separate incompatible chemical reactions, make reactions more efficient, etc.
Multicellularity: allowed for growth and specialization of certain cells
Larger size variation: more specialization and better competition
Structures for support and protection: cell walls & hard external shells
One difference between bacteria and protists in all of these categories: Cells, replication, and energy/nutrition
Cells: Bacteria are prokaryotes and unicellular, protists are eukaryotes and uni or multicellular
Replication: Bacteria asexually through binary fission, protists sexually or asexually and includes alternation of generations
Energy: Bacteria have 6 modes of nutrition, protists have 3
Two evolutionary novelties of gymnosperms and why they were adaptive.
“Naked” seeds - seeds not enclosed within an ovary like angiosperms. Seeds allow the embryo to remain dormant until conditions are favorable for growth.
Cones - Allows for wind dispersal. Reduces dependence on water for reproduction. Protects the naked seeds.
As you walk through a forest, are you more likely to notice the gametophyte of a moss or the gametophyte of a fern? Why?
Moss. Moss is gametophyte dominant, so their gametophyte stage is their largest stage. Ferns are sporophyte dominant, so their gametophyte stage is small and almost unnoticeable.
Two structural features that terrestrial plants evolved that helped reduce their risk of drying out (and explain how they prevent drying)
Cuticle: waxy layer that reduces water loss through tissues
Stomata: Cells that close openings to pores to reduce water loss
Sporopollenin: Covers and protects spores
Gametangia, seeds: reduce water loss through protection of reproductive cells