Life Sciences Revision Booklet - Microorganisms, Plants and Animals

Flashcards on Biodiversity and Classification

What are microorganisms?

Small living organisms that cannot be seen with the naked eye

Name the four types of microorganisms.

Viruses, bacteria, protists, and fungi

What are the main characteristics of viruses?

They are acellular and have no nucleus, cytoplasm, or organelles

What is the basic structure of a virus?

A central nucleic acid (DNA or RNA) surrounded by a protein capsule

How do viruses reproduce?

They are parasites that reproduce inside cells of living organisms

What are bacteria?

Small, unicellular organisms classified as prokaryotes

What does it mean for bacteria to be prokaryotes?

No membrane-bound organelles such as a nucleus, chloroplasts, or mitochondria

What shapes can bacteria have?

Rod-shaped (bacillus), spherical (coccus), spiral-shaped (spirillum), and comma-shaped (vibrio)

What are protists?

Unicellular or multicellular eukaryotes with a true nucleus

How do protists reproduce?

Through binary fusion, but some can reproduce sexually, e.g., some algae

What are fungi?

Unicellular (e.g., yeasts) or multicellular (e.g., mushrooms and molds) eukaryotes

What are the cell walls of fungi made of?

Consist of chitin

How do fungi obtain nutrients?

Saprophytes (live on dead organic matter) or parasites (feed on living material)

What is the role of nitrogen-fixing bacteria in plants?

Convert atmospheric nitrogen into nitrates that plants can absorb

What is the role of E. coli bacteria in the human intestines?

Produces vitamin K

Name a disease caused by a virus, bacteria, protist and fungi, respectively.

HIV/AIDS, Tuberculosis, Malaria, Thrush

What causes HIV/AIDS?

Caused by the Human Immunodeficiency Virus (HIV)

What causes Tuberculosis (TB)?

Caused by the bacterium Mycobacterium tuberculosis

What causes Malaria?

Caused by a protist of the genus Plasmodium and is spread by the female Anopheles mosquito

What causes Thrush?

Caused by a fungus called Candida albicans

What is the first line of defense in plants against infection?

Waxy cuticle, bark, and closely packed epidermal cells

What are the two types of immunity in animals?

Natural immunity (present at birth) and acquired immunity (develops after exposure to pathogens)

What does a vaccine consist of?

Dead or weakened micro-organisms or their toxins, that stimulate the production of antibodies

What are antibiotics?

Chemical substances that fight infections caused by bacteria, often obtained from fungi

What are the four main groups or divisions of the Kingdom Plantae?

Bryophytes, Pteridophytes, Gymnosperms, and Angiosperms

What are bryophytes?

Mosses

What are pteridophytes?

Ferns

What are gymnosperms?

Conifers and cycads

What are angiosperms?

Flowering plants

What is pollination?

Transfer of pollen from an anther to the stigma of the same or different flower of the same species