Bio Unit Test 1 Flashcards
When did protists first appear?
1.5 billion years ago
How big are protists (eukaryotes) in relation to prokaryotes?
10 times bigger than prokaryotes.
What made eukaryotes different from prokaryotes?
10 times bigger, had many chromosomes and organelles with their own membranes.
What is endosymbiosis?
The relationship in which single-celled organisms live within the cells of another organism.
Where did membrane bound organelles likely develop?
From the folded cell membrane of ancestral prokaryotic cells.
What makes mitochondria and chloroplasts different from other organelles?
They have their own DNA. They reproduce on their own.
What are protozoans?
Protists that eat or ingest material from their surroundings. (animal-like and were once classified as animals).
What are some examples of protozoans?
Zoo-flagellates, amoebas, ciliates.
What are the characteristics of a zooflagellate?
They have one or more flagella. Some are heterotrophic (feed on protists) and some are parasites (take nutrients from a host).
Name a possibly fatal sickness that is caused by a parasitic zooflagellate.
African sleeping sickness
What are amoebas?
Single-celled protozoans with no real body shape.
What do amoebas use to move and feed?
Temporary projections called pseudopods.
How does an amoeba eat?
By endocytosis.
What is endocytosis?
When particles of food are sealed off in food vacuoles in the cytoplasm.
What are ciliates?
Protozoans covered in cilia.
Name some characteristics of ciliates.
They have a rigid outer covering (pedicle/pellicle), 2 nuclei. They are aquatic, hetertrophic, and live in salt/fresh water.
What purpose does the pellicle of a ciliate serve?
Maintaining their shape.
Give an example of a freshwater ciliate.
Paramecium
Explain how ciliates eat.
- Beat cilia to bring food into their oral groove.
- The membrane pinches off and forms a food vacuole.
- The food vacuole travels into the cytoplasm.
- The food vacuole joins with a lysosome that breaks down the food.
- The unwanted is discharged through the anal pore.
How do ciliates reproduce?
Through binary fission mostly. Sometimes through conjugation.
What are fungus-like protists?
Heterotrophic decomposers that live in cool and damp habitats.
What are the 3 major phyla of fungus-like protists?
- Acellular slime moulds (live in colonies), cellular slime moulds, and water moulds.
What are sporozoans?
Protist that make spores.
What are some characteristics of sporozoans?
Non-motile and parasitic.
What is the most known sporozoan?
Plasmodium (causes malaria).
How do plasmodia infect humans with malaria?
- Spend part of their life cycle within human red blood cells.
- Red blood cell bursts open.
- The parasite’s toxins fill the bloodstream.
What are plant-like protists?
Multicellular protists that contain chlorophyll and undergo photosynthesis.
How do plant-like protists differ from plants?
The zygote of the alga is unprotected. The zygote of a plant is protected by the parental cells. Plant-like protists do not have tissues.
What are euglenoids?
Unicellular flagellates.
How does the euglena propel itself through water?
By using its flagellum.
What happens to euglenoids in the sunlight vs the dark?
Sunlight: autotrophic.
Dark: Lose its chlorophyll, becomes heterotrophic.
What are some characteristics of algae?
They all have chloroplasts, some are single-celled, some live in colonies, some are multicellular.
What are the 3 main groups of algae (the ones we have to know)?
Diatoms, dinoflagellates, green algae.
What are the characteristics of diatoms?
Yellow-brown, glass-like silica shells.
What are the characteristics of dinoflagellates? (6)
Singled-celled, 2 flagella, photosynthetic (most), move in spinning motion, can be luminescent, reproduce asexually.
What can dinoflagellates cause with their blooms?
Red tides.
Why are red tides bad?
They produce toxins.
What are the characteristics of green algae?
Single-celled or colonial,
2 flagella,
fresh water,
cellulose in their cell walls.
From what do we think plants originated from? Why?
Green algae because they have cellulose in their cell walls.
What are the characteristics of fungi?
Heterotrophic, eukarotic, saprobes.
What is a saprobe?
An organism that absorbs food from decaying matter.
How do fungi eat?
By releasing digestive enzymes into their environment that break down the decaying matter. Then they absorb the digested food through their cell wall.
How are fungi different than slime moulds?
Fungi absorb through endocytosis.
What are the bodies of fungi made of?
Filaments called hyphae. They grow into a tangled mess of filaments called mycelium.
What is a mycelium?
A network of hyphae.
What are the cell walls of fungi made of?
Chitin. (Not cellulose).
How do most fungi reproduce?
Sexually and asexually with spores.
What are spores?
Single reproductive cells with a haploid number of chromosomes.
What kind of fungi are in the division Zygomycota?
Fungi with spores that are in a CASE-like structure.
What kind of fungi are in the division Ascomycota?
Fungi with spores in a SAC-like structure.
What is an ascus?
A sac-like structure that holds spores.
What kind of fungi are in the division Basidiomycota?
Fungi with spores in a CLUB-like structure.
What are fungi with spores in a club-like structure called?
Basidia or basidium.
Why is lichen a symbiotic relationship?
Alga provides nourishment by photosynthesis and the fungus provides water, minerals, and protection from dryness.
What is mycorrhizae?
A symbiotic relationship between a fungus and the roots of plant.
Why is mycorrhizae a symbiotic relationship?
The fungus mycelium forms a web over the plants and passes them water. The plant provides amino acids and sugars to the fungus.
Why are the life cycles of fungi complicated?
Because nuclei are haploid.
Explain the life cycle of a fungus.
- Spores (haploid) germinate to produce hyphae.
- Hyphae fuse together to from dikaryotic cells.
- Makes a large, fruiting body.
- Basidia form on the underside. Haploid dikaryotes fuse into a zygote.
- The zygote undergoes meiosis, it produces 4 haploid spores.
What does haploid mean?
(of a cell or nucleus) having a single set of unpaired chromosomes.
What does dikaryotic mean?
A fungal cell which has precisely two genetically-distinct but allelically-compatible nuclei.
Are spores haploid or diploid?
Haploid.
Describe malaria.
An infectious disease caused by a parasitic protist called a plasmodium carried by the mosquito. Fever, chills, etc.
Describe African Sleeping sickness (trypanosomiasis).
An infectious disease caused by a parasitic protist called a trypanosoma carried by the tsetse fly. Coordination problems, fatigue, general confusion.
Name 4 diseases caused by protists.
- Malaria.
- African sleeping sickness.
- Giardiasis.
- Amoebic Dysentery.
What is Giardiasis caused by?
Drinking contaminated (from animal feces) water. The protist attaches itself to the intestinal wall.
What is Amoebic Dysentery (Montezuma’s revenge) caused by?
Drinking water contaminated with Entamoeb histolytica (amoeba).
Why do scientists study animals?
To help better understand ourselves and how to keep humans healthy from disease.
What do animals provide for us humans?
A source of food, pets.
How do animals help plants?
Some animals pollinate food sources.
Why are animals important culturally?
Throughout history animals have been symbols of beauty, power, freedom, and peace:
What is radial symmetry?
Symmetry around a central axis (spokes around a wheel)
Give an example of an animal with radial symmetry.
Jellyfish
What are nerve cells?
Specialized nerve cells that become specialized during embryonic development.
What are germ layers?
The layer of cells that develops into specialized tissues.
Name the three germ layers.
Ectoderm, endoderm, and mesoderm.
What does ectoderm turn into?
Skin and nervous system.
What does endoderm turn into?
Inner lining of gut (resp)
What does mesoderm turn into?
Circulatory, reproductive, excretory and muscular systems.
What is phylogeny?
Evolutionary history.
What is the difference between vascular and non-vascular plants?
Vascular plants have structural support like stems or bark.
Non-vascular plants do not have structural support, they grow right along the ground.
What is believed to be the ancestor to all plants?
Ancestral green algae.
Give an example of a non-vascular plant.
Moss.
What characteristics do all plants have?
eukaryotic, multicellular, photosynthetic, cell walls containing cellulose, dwell on land or in water.
Plant cell walls contain cellulose. What do fungi contain?
Chitin.
What makes the life cycle of plants different to that of animals?
It alternates between haploid and diploid generations. (2 cycles back to back) Animal life cycles are always diploid.
Explain the life cycle of a plant.
- Haploid spore cells divide and form new plants.
- Haploid plants produce gametes which fuse to form a diploid zygote.
(haploid gametophyte becomes diploid sporophyte).
What is a bryophyte?
A non-vascular plant.
What are some characteristics of bryophytes? (4)
- They grow where food is.
- They lack true roots, stems, leaves and transport tissues.
- They are short, grow densely packed in moist environments (bark of trees, rocks, buildings.)
- Reproduce either asexually or sexually using spores not seeds.
How do bryophytes reproduce asexually?
Through vegetative propagation.
Explain vegetative propagation.
A small segment branches off and grows into an identical plant.
Explain how bryophytes reproduce sexually.
- Sperm swim to female reproductive organ.
2. Water must be present for fertilization.
How are spores carried?
By wind or water.
What is a tracheophyte?
A vascular plant.
Name some characteristics of tracheophytes.
- They have adapted to life on land.
- Have transport tissues take take nutrients and minerals from the soil to the top of the plant.
- Their vascular tissues allow them to grow tall and not be confined to food source.
What are the two types of tracheophytes?
Spore producing and Seed producing.
What are the transport tissues of a plant called?
Xylem: dead cells that transport water.
Phloem: Live cells that transport sugars.
What are some characteristics of spore -producing tracheophytes?
Related to ferns, leaves in “fronds”, underground stems called rhizomes, produce spores.
Give some examples of spore-producing tracheophytes.
Club mosses, horsetails.
What are some characteristics of seed-producing tracheophytes?
Have specialized organs (leaves, stems, roots), cones or flowers are produced, reproduce sexually by pollination.
What does pollination need to spread?
Only wind and animals, not water.
What are gymnosperms?
Seed-producing tracheophytes that produce cones.
Which characteristic do all gymnosperms have in common?
They all have cones which they use to reproduce.
Give an example of a gymnosperm.
Conifers, gnetae, ginkgus, cycads.
How are the cones used to reproduce?
The male cones produce pollen. The female cones produce ovules.
What are angiosperms?
Seed-producing tracheophytes that flower.
What are some characteristics of angiosperms?
- flowering plants.
- Most successful plants.
- Reproduce with flowers.
How do angiosperms reproduce using flowers?
- The pistil holds the ovum.
- The ovum must be fertilized by a pollen grain.
- After fertilization, fruit develops with fertilized seed inside.
Where is the sperm cell located in angiosperms?
In the pollen grain.
What is the female part of the flower called?
The ovum.
Why are angiosperms the most successful plants?
Because they receive help from the wind, water, insects to reproduce.
What is the principle difference between mitosis and meiosis?
Mitosis results in two identical daughter cells, whereas meiosis results in four sex cells.
Mitosis: Haploid —- two identical haploid cells (n→n).
Meiosis: Diploid——four haploid cells.
Are humans haploid or diploid?
Diploid. A typical human somatic cell contains 46 chromosomes: 2 complete haploid sets, which make up 23 homologous chromosome pairs.
What is a gametophyte?
Dominant form in bryophytes. Gamete-producing and usually haploid phase, producing the zygote.
From where does the sporophyte arise?
The zygote.
An egg and a sperm cell are both _______.
Haploid cells that fuse together to form a zygote.
What is a zygote?
A diploid cell resulting from the fusion of two haploid gametes; a fertilized ovum.
What is a sporophyte?
Dominant form in tracheophytes. Spore-producing, asexual and usually diploid phase.
From where does the gametophyte arise?
The spores.
What characteristics do all animals have?
Multicellular, heterotrophic, use oxygen for aerobic respiration, do not have cell walls, cell membranes are in contact with each other.
