Biodiversity Test

What makes a species unique?

Genetic identity, morphology, reproductive isolation, ecological niche.

Haploid Stage in Fungi Cycle

Spores germinate and grow into a haploid mycelium containing a single set of chromosomes.

Dikaryotic Stage in Fungi Cycle

Two haploid cells fuse their cytoplasm, but nuclei remain separate, forming a dikaryotic mycelium.

Diploid Stage in Fungi Cycle

Nuclei within the dikaryotic cells fuse, forming a diploid zygote which undergoes meiosis to produce haploid spores.

Life cycle of the malaria (Plasmodium) parasite

Involves two hosts: humans and mosquitoes, where sporozoites infect liver cells in humans.

How malaria spreads and how to eliminate it best

Can be treated with drugs but is more effective to eliminate the vector (mosquitoes).

Harmful organisms

Pathogens (e.g., Plasmodium) and invasive species (e.g., zebra mussels).

Useful organisms

Decomposers (fungi, bacteria) and nitrogen-fixing bacteria (Rhizobium).

Taxon groups

Hierarchy levels of classification: Kingdom, Phylum, Class, Order, Family, Genus, Species.

Kingdom

A major classification group based on shared traits such as Animalia, Plantae, Fungi.

Genus and species naming

Genus is capitalized; species is lowercase, both italicized or underlined.

Chemoautotroph

Organisms that obtain energy through inorganic substances and CO2.

Photoautotroph

Organisms that obtain energy from light and use CO2.

Chemoheterotroph

Organisms that obtain energy from organic compounds.

Photoheterotroph

Organisms that obtain energy from light and organic compounds.

Archaea vs Eubacteria

• Archaea:

  • Live in extreme environments (e.g., hot springs, salty areas).

  • Cell walls lack peptidoglycan.

• Eubacteria:

  • Found in diverse environments.

  • Cell walls have peptidoglycan

Good uses of bacteria

Waste management, sewage treatment, dairy foods, digestion, pest control.

Bacteria compared to viruses

Bacteria are living, prokaryotic organisms; viruses are non-living and require a host.

Conjugation in bacteria

1. What It Is: A process where bacteria transfer genetic material to each other through a pilus (a tiny bridge).

2. The Process:

   • Donor bacterium grows a pilus.

   • The plasmid (small DNA circle) is copied and passed to the recipient.

3. What It’s Used For:

   • Sharing helpful traits, like antibiotic resistance or toxin production.

What is a virus?

A virus has either DNA or RNA, protected by a protein coat called a capsid.

Why don’t viruses belong to a kingdom?

Because they are not cells and only exhibit living characteristics in a host.

Five characteristics that classify a virus

1.  Morphology (shape)

2. Nucleic acid type (DNA or RNA)

3. Method of replication (eg. lytic vs lysogenic)

4. Host organism

Lytic cycle

Virus infects the host and forces it to make new viruses.

Lysogenic cycle

Virus integrates its DNA into the host's genome and remains dormant.

Difference between RNA and DNA viruses

DNA viruses are stable with less mutation; RNA viruses mutate quickly and are less stable.

How viruses insert their DNA into a host

Virus binds to host cell and injects its genetic material.

What are fungi?

Living organisms that are more closely related to animals and have distinct characteristics.

Recognizing fungi

Eukaryotic, non-photosynthetic, absorb food through osmotrophy, can be unicellular or multicellular.

Structure of fungi

Body is primarily mycelium, with spores for reproduction.

How fungi reproduce asexually

By producing spores that grow into new fungi under favorable conditions.

Categories of fungi

1. Saprobes: Feed on dead or decaying matter, recycling nutrients (e.g., mushrooms).

2. Parasites: Feed on living organisms, sometimes harming them (e.g., Athlete’s foot fungus).

Importance of fungi

Decompose dead matter, used in medicine and food, and form symbiotic relationships.

What are protists?

Eukaryotic, single-celled organisms that can be plant-like, animal-like, or fungi-like.

How do bacteria, viruses, fungi, and protists compare?

Bacteria are prokaryotic; viruses are non-living; fungi and protists are eukaryotic.

Difference between eukaryotic and prokaryotic organisms

Eukaryotic: Have a nucleus and organelles (e.g., protists, fungi).

Prokaryotic: Lack a nucleus and organelles (e.g., bacteria).

Three categories of protists

Animal-like (heterotrophic)

plant-like (photosynthetic)

fungi-like (decomposers).

Four groups of animal-like protists based on movement

• Zooflagellates - Those with flagella

• Ciliates -Those with cilia

• Pseudopods -those with pseudopods 

• (ameba)

• Sporozoans - “Others”

Plant-like protist: Diatoms

 - single celled, key food source in water ecosystems

- think “algae”

Plant-like protist: Green algae

• Has two flagella

• Live in freshwater

• Thought to have given rise to first land plants

• single celled or multicellular

Plantlike protist->Dinoflagellates

• single celled, have two flagella

• Move in spinning motion

• Are luminescent

• Rapid growth called a “bloom”

What are the three major phyla of fungi-like protists?

Acellular slime moulds

cellular slime moulds

water moulds.

General characteristics of plants

• Eukaryotic 

• Multicellular

• Carry out photosynthesis (autotrophs)

• Have cell walls containing cellulose

• Sessile (can’t move from place to place)

Four main groups of land plants

1. Bryophytes: most common are mosses

2. Pteridophytes: includes ferns

3. Gymnosperms: includes pines and other conifers

4. Angiosperms: flowering plants

Vascular vs nonvascular plants

• Vascular plants: Have tissues (xylem and phloem) for transporting water and nutrients.

• Nonvascular plants: Lack vascular tissues and rely on diffusion (e.g., mosses).

Difference between xylem and phloem

Xylem transports water; phloem transports food.

General characteristics of animals

• Heterotrophic, 

• multicellular eukaryotes

• Lack cell walls

• Use oxygen for aerobic respiration

• Primarily sexual reproduction

• Specialized nervous and muscle tissue

Characteristics used to classify animals

• Body symmetry

• Degree of cell organization

• Body cavity (presence or absence of a coelom) 

• Segmentation

• Movement

• Reproduction

Body symmetry types

Asymmetry (sponges)

radial symmetry (octopus)

bilateral symmetry (humans)

What are invertebrates?

Animals without a backbone.

Examples: Insects, mollusks, and arthropods (e.g., Insecta, Mollusca).

What are vertebrates?

Animals with a backbone.

Examples: Mammals, birds, reptiles, amphibians, and fish (e.g., Mammalia, Aves, Reptilia).

Key differences between invertebrates and vertebrates

Invertebrates lack a backbone; vertebrates have one.

Three groups of mammals

Monotremes (egg-laying),

marsupials (pouched),

placental mammals.

Aerobes

Organisms that use oxygen for respiration.

Anaerobes

Organisms that do not require oxygen for respiration.

Obligate aerobes

Organisms that need oxygen to survive.

Obligate anaerobes

Organisms that are killed by the presence of oxygen.

Facultative anaerobes

Organisms that can survive with or without oxygen.