Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Biology > Diversity of Living Things > Flashcards

Diversity of Living Things Flashcards

1
Q

Taxonomy

A

The science of classifying groups of organisms based on their characteristics
Developed by Carolus Linneaus (only physical characteristics)
Now also use genetic and biochemical characteristics

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Taxon Order

A

8 different taxa (sing. taxon): Kingdom, Phylum, Class, Order, Family, Genus, Species
Domain - largest, based on cell type, often skipped

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Species

A

Individuals that can interbreed and produce fertile offspring

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Types of Evidence

A
  1. Anatomical - do the structures of the organisms look the same?
  2. Physiological - do the proteins and enzymes in the cells work the same?
  3. DNA - how genetically closely related are the genes and the proteins they make?
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Prokaryotes

A
  • cells that do not contain a true nucleus
  • smaller (1-10 micrometers µm)
  • DNA: chromosomes, plasmids (in nucleoid region)
  • Genome: single chromosome
  • Cell: unicellular - one cell
  • Organelles: ribosomes (proteins), no membrane bound organelles
  • Metabolism: anaerobic
  • Division (asexual): binary fission
  • Reproduction (sexual): conjugation
  • Movement: flagella
  • Cell wall: present
  • Examples: bacteria (E. Coli)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Eukaryotes

A
  • cells that contain a true nucleus
  • bigger (100-1000 micrometers µm)
  • DNA: bound within a membrane
  • Genome: several chromosome
  • Cell: multicellular - many cells
  • Organelles: membrane bound organelles
  • Metabolism: aerobic
  • Division (asexual): mitosis
  • Reproduction (sexual): meiosis
  • Movement: flagella (sperm), cilia
  • Cell wall: plants
  • Examples: plants, animals, protists
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Kindom:
Cell type
Number of cells
Cell Wall
Nutrition
Reproduction

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Bacteria

A

Eubacteria
- prokaryotic, unicellular, cell wall present (peptidoglycan)
- auto/hetero
- binary fission/conjugation
- decomposers, O2 and N2 producers
- E. coli, cyanobacteria

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Archaea

A

Archaeabacteria
- prokaryotic, unicellular, cell walls are unique
- auto/hetero
- binary fission/conjugation
- harsh/extreme environments
- acidophiles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Eukarya

A

Protista, fungi, plantae, animalia - eukaryotic, organelles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Protista

A
  • eukaryotes, unicellular, cell wall present
  • auto/hetero
  • asexual/sexual
  • important producers
  • plankton, amoeba, algae
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Fungi

A
  • eukaryotes, multicellular, cell walls present (chitin)
  • heterotrophic
  • asexual/sexual
  • decomposers, food (yeast)
  • mushrooms, mold, yeast
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Plantae

A
  • eukaryotes, multicellular, cell wall present
  • autotrophic (photosynthesis)
  • asexual/sexual
  • food, O2, rubber, fuel, dyes, medicine
  • angiosperms (flowering), gymnosperms (cone baring)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Animalia

A
  • eukaryotes, multicellular, cell wall absent
  • heterotrophic
  • mitosis/meiosis
  • present in all food chains
  • insects, reptiles, mammals
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Biological species

A

Organisms can successfully breed and produce fertile offspring. Only works for living, sexually reproducing organisms

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Morphological species

A

Comparing the measurement and physical description. Used for plants and asexually reproducing organisms

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Phylogenetic species

A

Looks for evolutionary relationships between organisms. Usually based on DNA studies or fossil evidence

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Dichotomous keys

A

Dichotomous - divide in two
Scientists use the key and ask yes/no questions to classify a newly discovered organism compared to existing organisms.
Based on known species characteristics of organisms.
Can be shown as a branching tree diagram.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Questions asked in a dichotomous key

A

Is it multicellular?
Does it have tissues?
Radial symmetry?
Bilateral symmetry?

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Binomial Nomenclature

A

Carolus Linnaeus.
Every species has a unique two part scientific name.
1. Genus and species
2. Underlined/italicized
3. Genus is capitalised
4. species is lower-case
5. Latin
6. Unique in the same Genus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Purpose of Binomial Nomenclature

A

Common names of an organism are different in every language, so the scientific names ensure communication

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Flagella

A

Whip-like tail that extends from the cell wall
Provides movement (swimming)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Slime Capsule

A

Outer coat of thick gelatenous layer that allows bacteria to stick to surfaces
Helps protect against white blood cells and keep from drying out

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Cell Wall

A

Composed of sugars and amino acid molecules forming a rigid material that gives bacteria shape

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Cell Membrane

A

Semi-permeable membrane that allows the movement of substances (nutrients, wastes) in and out of the cell

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Pili

A

Bridge structure that allows for passage of DNA between cells in sexual reproduction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Cytoplasm (cytosol)

A

Fluid medium; contain dissolved nutrients, minerals, and salts

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

DNA

A

Genetic material that contains genes for making protein
Continuous loop that makes a single chromosome

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Plasmids

A

Small rings of additional DNA that float freely in the cytoplasm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

Ribosomes

A

Involved in the production of protein

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Bacteria Shape

A

Cocci (coccus) - round shape
Bacilli (bacillus) - rod shape
Spirilli (spirillum) - spiral shape

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

Bacteria Groupings

A

Diplo - pairs
Staphylo - clusters
Strept - chains

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

Cell Wall Structure

A

Gram stain (Hans Gram) shows basic differences in the arrangement of amino acid and sugar molecules in bacterial cell walls
Gram positive bacteria - thick protein layer on cell wall and stain purple
Gram negative bacteria - thin protein layer on cell wall and stain pink

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

Asexual Reproduction

A

Binary Fission:
1. Copy of DNA (single chromosome)
2. After reaching a certain size, it elongates, separating the 2 chromosomes
3. Cell builds a partition, septum, between them
4. Cell splits into 2 identical cells
In favourable conditions - 20 min (exponential growth)
Limitations: environment, food resources, waste build-up (toxic)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

Sexual Reproduction

A

Conjugation:
1. Bacterial cells link through pili
2. One bacterium transfers all/part of its chromosomes to the other (plasmid may also be transferred)
3. Bacteria with new genetic makeup produce new cells through binary fission
Can go dormant forming endospores to survive unfavourable conditions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

Endospores

A

Tough outer covering that surrounds their DNA and a small amount of the cytoplasm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

Carbon and Energy Sources

A

Obtain energy and nutrients by performing photosynthesis, decomposing dead organisms/wastes, or breaking down chemical compounds

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

Bacterial Nutrition

A

Autotrophic (some): make own food from raw material
- Photosynthetic: photosynthesis
- Chemosynthetic: make food from the chemicals in the environment
Heterotrophic (most): cannot make own food and obtain food from an outside source
- Parasitic: live on or in other things
- Saprophytic: live off dead organic matter or wastes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

Applications of Bacteria

A
  • create food products (yogurt)
  • fermentation (brewing)
  • agriculture (composting)
  • killing plant pests
  • biotechnology (fuels, medicine)
  • genetic engineering (enzymes)
  • gene therapy
  • clean up spills and toxic waste
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

Virus

A

Smallest and simplest microorganism.
Not a living organism, since they have no cellular structure - no growth, repair, replication.
Not capable of independent survival (evolved after 1st cells).
First viewed in 1950 through early electron microscope, now 160 major groups.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

Virus Structure

A

20nm - 400 nm
1. DNA/RNA genetic material (single/double-stranded or fragmented)
2. Protein coat - capsid (determined by the arrangement of viral proteins)
3. Receptors - attach to specific host cells on specific receptor sites on the plasma membrane of the host cell

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

Virus shape

A
  1. Helical
  2. Polyhedral
  3. Enveloped
  4. Complex
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

Virus classification

A

According to what type of diseases they cause.
Human viruses - 21 groups

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

Epidemic

A

Major increase in disease occurrence

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

Pandemic

A

An epidemic occurring worldwide, or over a very large area, crossing international boundaries and affecting a lot of people

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

Virus Replication

A

Lytic cycle:
1. Attachment
- attaches to host cell via receptors
2. Entry
- enters cell bty injecting nucleic acid or creating a vacuole that is later released
- injects DNA into host cell
3. Synthesis
- host cell replicates viral DNA
4. Assembly
- new viruses are made (coat and DNA)
5. Release - lysis
- cell bursts, releasing new viruses

20 - 40 minutes. 100s of new viruses.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

Lysogeny Cycle

A
  • invade the cell but do not kill it
  • virus is in a dormant state within the cell
  • it is a provirus - viral genetic material is integrated into cell DNA, and passed to the daughter cells
  • may be later activated by stimuli
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
48
Q

Retrovirus

A

Contain enzyme, reverse transcriptase, which causes the host cell to copy the viral RNA into DNA. Retroviral DNA is integrated into host DNA (now called provirus)
Example: HIV

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
49
Q

Viruses differ based on

A

Structure, genome type, host type, and transmission mechanism

50
Q

Envelope

A

Some viruses develop an envelope made of the hosts cell membrane when it envelops the virus as it exits the cell by budding from the surface. Contains embedded viral proteins

51
Q

Genetic material variation

A
  1. Type of nucleic acid (DNA or RNA)
  2. Number of strands ( single/double)
  3. RNA genomes vary in sense of strands (positive or negative)
  4. Structure (circular, linear, fragmented)
52
Q

Vector

A

An intermediate organism that some viruses need in order to be transmitted from one type of host to another

53
Q

Zoonotic

A

A virus that is transmitted from an animal to humans (i.e. from rats or bats)

54
Q

Plant virus

A

Tobacco Mosaic Virus (TMV)
the first virus to be identified and described

55
Q

Infect all vertibrates

A

Adenoviruses and papillomaviruses

56
Q

Bacteriophage

A

T7

57
Q

Segmented genome

A

Gives an advantage, since when 2+ viruses of the same type (i.e. influenza viruses) infect the same cell, they are able to rearrange. New virus subtypes can arrise, making it more effective and able to infect a greater variety of hosts

58
Q

Common cold

A

Rhinovirus

59
Q

Vaccines not available

A

HIV, Adenoviruses, Zika, T7 (bacteriophage), TMV (plants are bred to resist)

60
Q

Vaccines available

A

Rabies, Influenza A, Coronaviruses, Ebola, Papillomaviruses

61
Q

Papillomaviruses

A

Papillomas - warts
Symptoms: benign growths (warts) on skin, respiratory tract, or genitals; several types of cancer
Human papillomavirus (HPV) can cause genital warts and cancer

62
Q

Zika virus

A

Concern to pregnant women due to the possibility of their children bein born with microcephaly or other neurological defects

63
Q

HIV

A

Human immunodeficiency Virus
Acquired immunodificiency syndrom - advanced stages of HIV
Infects and destroys immune cells, so the more the infection progresses, the less the person can fight back

64
Q

Infection

A

The invasion of germs (i.e. bacteria, viruses) where they attack and multiply, which causes illness

65
Q

Microphages

A

White blood cells that swallow and digest germs, and dead or dying cells.
Leave behind part of the germ, antigen, which the body identifies as dangerous and stimulates to attack.

66
Q

Antibodies

A

Attack the antigens left behind by the macrophages
Produced by B-lymphocytes

67
Q

B-lymphocytes

A

Defensive white blood cells

68
Q

T-lymphocytes

A

Another type of defensive white blood cell.
Attack cells in the body that have already been infected.

69
Q

How is immunity built?

A

It can take several days to make and use germ-fighting tools against a new germ.
After, the body keeps a few T-lymphocytes (memory cells) that act quickly if the same germ is encountered again
When familiar antigens are detected, B-lymphocytes produce antibodies to attack them

70
Q

Vaccines

A

Help develop immunity by immitating an infection.
Do not cause illness, but do get the body to produce T-lymphocytes and antibodies.
May cause minor symptoms.
Leaves the body with a supply of “memory” T-lymphocytes and B-lymphocytes
Takes a few weeks, so if infected right before or after, can get disease

71
Q

Approaches to designing vaccines

A
  • how it infects cells and how the immune system responds to it
  • regions of the world where the vaccine would be used (affect the strain of a virus and environmental conditions) (delivery option may depend on this)
72
Q

Live, attenuated vaccines

A
  • fight viruses
  • contain a version of the living virus but weakened
  • closest thing to a natural infection, good teachers for the immune system
  • not everyone can receive (children with weakened immune systems)
  • Examples: measles, mumps, rubella vaccine (MMR), varicella (chickenpox)
73
Q

Inactivated vaccines

A
  • fight viruses
  • made by inactivating/killing the virus
  • produce immune responses in different ways that live vaccines (multiple doses often required)
  • Example: incativated polio vaccine
74
Q

Toxoid vaccines

A
  • fight bacteria that produce toxins in the body
  • toxins are weakened (called toxoids) for the vaccine
  • Example: DTaP (diptheria and tetanus toxins)
75
Q

Subunit vaccines

A
  • include inly parts (subunits) of the virus/bacteria, not the entire germ
  • only the essential antigen
  • side effects are less common
  • Example: pertussis (whooping cough) component of DTaP vaccine
76
Q

Conjugate vaccines

A
  • fight a different type of bacteria
  • bacteria have antigens with outer coating of sugar-like substance (polysaccharide), which disguises it from a child’s immature immune system
  • vaccines connect the polysaccharides to antigens that the immune system responds to
  • Example: Haemophilus influenzae type B (HiB) vaccine
77
Q

More than one dose

A
  1. Primarily inactivated vaccines
    - first dose does not provide total immunity, more is needed
    - Ex: vaccine against Hib, meningitis
  2. Booster
    - DTaP (diphtheria, tetanus, pertussis) vaccine give children immunity through 4 shots. After a while, it wears off, so booster is needed (4 through 6 y.o., another at 11/12 y.o.)
  3. Primarily live vaccines
    - more than one dose needed for best immune response
    - Ex: MMR vaccine
  4. Flu vaccine
    - virus is different from year to year
78
Q

Archaea

A
  • prokaryotes, unicellular
  • live in extreme environments
  • live without oxygen (anaerobic)
  • obtain energy from inorganic molecules or light
79
Q

Special cell membranes

A

Extreme hot temperatures: unusual lipids (fats) that remain stable
Extreme cold conditions: high contents of other fatty substances that remain fluid and functional

80
Q

Bacteria vs Archaea

A

Similarities:
- prokaryotes (no nucleus/organelles)
- unicellular
- common ancestor
Bacteria:
- cell walls from peptoglycen
- cannot survive extreme conditions
- more standard energy production
Archaea:
- call walls from different material
- survive extreme conditions
- less standard energy procedure

81
Q

Methanogens

A

Methane-producing archaea:
- live in oxygen-free environments (below swamps, marshes
- use CO2, N2 gas, hydrogen sulfide as a source of energy and produce methane as waste

82
Q

Halophiles

A

Salt-loving archaea:
- live in extremely saline environments (i.e. salty pools)
- so well adapted, could not live in weaker salt solutions

83
Q

Thermoacidophiles

A

Heat- and acid-loving archaea:
- live in extremely hot (above 80C) and acidic environments
- ex: hot sulfur springs, volcanoes, deep sea vents

84
Q

Origins of Archaea

A

Early atmosphere lacked oxygen - made of water vapour, methane, and ammonia
Alexander Oparin (1930s) hypothesized that life began in the ocean. Sun’s energy and electrical energy from lightning caused chemical reactions in the atmosphere = organic compounds

85
Q

Applications of Archaea

A

Because archaean enzymes can withstand extreme conditions, they are better to use in biotechnology and industry. They do not break down as easily, so reduce costs and create new biotechnology techniques for harsh conditions.
Ex: PCR requires cycling of enzymes between high and low temperatures for copying, standard enzymes are destroyed, archaean survive. Now fully automated procedure

86
Q

Protista

A
  • eukaryotic
  • most are aerobic and unicellular (can be colonial)
  • moist environments
  • 200 000 species
87
Q

Applications of Protists

A
  • in some ecological food webs, play producer and decomposer roles
  • food source and oxygen producers (algae)
  • medicine for high blood pressure, digestion, arthritis
88
Q

Protozoa

A

Animal-like:
- heterotrophs (injest other organisms/dead matter)
- unicellular
- no complex systems (nervous system)
- classified based on how they move and where they live:
1. Zoomastigina/Flagellates (flagella)
2. Sarcodina/Pseudopods (false legs out of cytoplasm - pseudopodia)
3. Ciliaphora/Ciliates (cilia)
4. Sporozoa/Sporozoans (parasites - non-motile)

89
Q

Flagellates

A

Zoomastigina/zooflagellates: the motorboats
- free-living in fresh water and marine habitats
- whip-like extension (flagella) to move
- some cause diseases, like Giardia lamblia (diarrhea)

90
Q

Pseudopods

A

Sarcodina: the blobs
- most are free-living
- no cell wall
- move using pseudopodia - plasma (cytoplasm) extensions
- engulf bits of food by phagocytosis - flowing around and over food particles
- reproduce by binary fission

91
Q

Ciliates

A

Ciliaphora: the hairy ones
- live in fresh water and marine habitats
- move by beating tiny hairs - cilia
- usually reproduce by binary fission, but can reproduce sexually by conjugation

92
Q

Sporozoans

A

Sporozoa: the parasites
- non-motile
- must live inside a host
- one causes malaria (plasmodium) (2 hosts)

93
Q

Protophyta

A

Plant-like:
- autotrophic (photosynthetic)
- can be unicellular, multicellular, or colonial
- 4 main groups:
1. Algae
2. Euglenophyta/Euglenoids
3. Chrysophyes/Diatoms
4. Pyrrophyta/Dinoflagellates

94
Q

Algae

A
  • unicellular/multicelluar
  • photosynthetic and have chlorophyll
  • can be red, green, or brown
  • no roots, stems or leaves
95
Q

Euglena/Euglenoids

A
  • Euglenophyta
  • aquatic
  • move around like animals (flagella)
  • photosynthetic in light
  • heterotrophic in dark
  • reproduce asexually by binary fission
96
Q

Diatoms

A
  • Chrysophyes
  • have shells made if silica so are glass-like
  • photosynthetic pigments called carotenoids give them a golden colour
97
Q

Dinoflagellates

A
  • Pyrrophyta
  • spin around using two flagella
  • cause Red Tides
  • form toxins that can kill animals and sometimes people
98
Q

Fungus-like

A

The moulds:
- heterotrophic: saprophytic
- live in cool, damp habitats
- have cell walls
- reproduce with spores
- 2 main types:
1. Slime moulds (Oomycotes)
2. Water moulds (Myxomycotes)

99
Q

Fungi

A
  • eukaryotic kingdom that includes mushrooms, mildews, moulds, yeasts
  • heterotrophs: release digestive enzymes into surroundings callled extracellular digestion
  • non-motile
  • plant-like since they have cell walls (but made of chitin)
  • few are unicellular (yeast)
  • majority are multicellular: bodies made of hyphae
  • most are saprophytes (decomposers) - recycle nutrients
  • some are parasitic (athlete’s foot, ringworm)
  • many fungi live in symbiotic relationships
  • origins unknown - may have evolved separately from more than 1 origin
100
Q

Application of Fungi

A
  • decomposers
  • Mycorrhizal fungi are essential for the growth of most plants
  • human nutrition (mushrooms)
  • agents of fermentation in the production of bread, cheeses, alcoholic beverages
  • penicillin
101
Q

Hyphae
Septa
Mycelium

A

Network of fine filaments
Divide hyphae into individual cells
Loose branching network of hyphae

102
Q

Symbiotic relationships of Fungi

A

Mycorrhiza (fungus-root):
- mutualistic fungi that live in close contact with roots of trees
- plant photosynthesizes, fungus takes up nutrients and water
Lichens:
- mutualistic symbiotic organisms. They comprise a fungus living with algae or cyanobacterium.

103
Q

Ascomycota

A

Sac Fungi:
- largest group
- yeast cells, morels, truffles
- lichen

104
Q

Basidiomycota

A

Club Fungi:
- common mushrooms

105
Q

Zygomycota

A

Zygote Fungi:
- zygote forming fungi
- bread molds

106
Q

Deuteromycota

A

Imperfect Fungi:
- only have an asexual phase
- athlete’s foot
- where we get penicilin

107
Q

Fragmentation (asexual reproduction)

A

Pieces of hyphae break off and grow into new mycelia

108
Q

Spore production

A

May be asexual (mitosis) or sexual (meiosis)

109
Q

Zygospore formation (sexual reproduction)

A

Diploid structures that develop after hyphae of opposite types (+,-) combine.
Remains dormant until favourable conditions return. 3rd hyphae (sporangiophore) is formed in which asexual spores develop

110
Q

Basidiocarp formation (sexual reproduction)

A

Reproductive structures on mushrooms that produce basidiospores on club-shaped hyphae called basidia

111
Q

Plantae

A
  • multicelular, eukaryotic, autotrophs
  • cell wall (cellulose)
  • non-motile
  • classified based on: presence/absence of vascular tissue and seeds
112
Q

Non-vascular Plants (Bryophyta)

A
  • have no vascular tissue (roots, stems, leaves, tubes of xylem and phloem)
  • dependent on diffusion and osmosis to transport nutrients
  • don’t have roots, but have root-like structures
  • have male and female gametes
  • limited growth
  • dependant on water
  • phyla:
    1. Mosses (Bryophytes)
    2. Liverworts (Hepatophytes)
    3. Hornworts (Anthocerophytes)
113
Q

Xylem
Phloem

A

Vascular tissues conducting water and minerals
Vascular tissues conducting food

114
Q

Vascular Plants

A
  • have organ systems: roots, stemes, leave
    Pteriodophytae (without seeds)
    Angiosperms and gymnosperms (with seeds; do not have to live in water)
115
Q

Pteriodophytae (vascular seedless)

A
  • first seedless vascular plants (mostly extict)
  • have vascular tissue, so grow tall
  • dispersed by windblown spores
  • gametes need moisture to reproduce sexually (sperm is flagellated), so limited to moist environments
  • phyla:
    1. Club Mosses (Lycopodophytes)
    2. Horsetails (Sphenophytes)
    3. Ferns (Pteridophytes)
    4. Whisk Ferns (Psilotophytes)
116
Q

Seeds

A
  • plant organ that contains embryo with a food supply, covered by a protective coat
  • advantages:
    1. protection from environment (cold, dry conditions)
    2. doesn’t need water
    3. can be carried over long distances
117
Q

Gymnosperms

A

Conifers (“naked seed”)
- have seeds that are exposed on the surface of cone scales
- all cone bearing plants (fir, spruce, cedar)
- advantages:
1. cone shaped - snow slides off
2. bark - protects stem, reduces water loss
3. needles - reduces rate of evaporation
4. evergreen - don’t shed all needls at once

118
Q

Cone

A
  • main reproductive structures
  • male cones are soft and short lives (sperm)
  • female cones are hard and long lived (eggs)
  • wind moves pollen (sperm) to fertilize eggs
119
Q

Angiosperms

A

“Flowering plants”:
- plant that protect their seeds within the body of a fruit
- include flowers, trees, shrubs, grasses, and herbs
- reproductive structures are part of the flower and the fertilized zygote is the seeds that grow in it
- fruit - a mature ovary that protects and disperses dormant seeds
- advantages:
1. Scented and colourful which helps pollination
2. Reproduce sexually
3. Can self pollinate
4. Fruit helps with seed dispersal
5. 47% of them are polyploid (3+ chromosomes)
- divided into 2 classes based on number of seed leaves inside the seed (cotyledons)
1. Monocot (one seed leaf)
2. Dicot (two seed leaves)

120
Q

Advantages of poliploidy

A
  1. Reproduce asexually (fast & greater numbers)
  2. Even number of chromosomes:
    - produces larger fruit
    - ex. Potatoes (4n), apples, strawberries
    - ex. Wheat: 6n for bread
  3. Odd number of chromosomes:
    - sterile – can’t pair during meiosis
    - ex: seedless fruit, less bitter cucumbers
121
Q

Applications of Plants

A
  • important food and oxygen source (photosynthesis)
  • products like paper, rubber, wood and cotton
  • medicine derived from plants
122
Q

Alternation of Generations

A
  1. Gametophyte: This is the haploid stage, meaning it has one set of chromosomes. It produces gametes (sperm and eggs) through mitosis.
  2. Fertilization: When a sperm and an egg unite, they form a diploid zygote, which has two sets of chromosomes.
  3. Sporophyte: The zygote grows into the diploid sporophyte, which produces spores through meiosis. These spores are haploid.
  4. Spores: Spores grow into new gametophytes, completing the cycle.

Biology (6 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions