Biology Concepts Review: Phylogeny, Plant Reproduction, and Microorganisms

Posted on Oct 23, 2025 in Biology

Taxonomy and Phylogenetic Principles

Fungi Classification in the Two-Kingdom System

Question: In the two-kingdom system, why were fungi classified in the kingdom Plantae? Answer: They are sedentary.

Eukaryotic Domains

Question: How many eukaryotic domains are there? Answer: One.

Phylogenetic Tree Terminology

  • The horizontal line indicating a branch on a phylogenetic tree represents ancestral forms of the named taxon, thereby illustrating the evolutionary lineage leading to that taxon.
  • Sister taxa are groups of organisms that share a unique common ancestor not shared by any other groups.
  • The point at which two or more lineages diverge from their common ancestor is called a branch point or node.
  • Each branch tip on a phylogenetic tree represents a specific group of organisms known as a taxon.

Phylogenetic Relationships (True/False)

  • Fishes and chimps have no common ancestors. False
  • Frogs and humans are more distantly related than are lizards and humans. True
  • In this tree, lizards are the sister taxon of the lineage that includes humans and chimps. True
  • The taxon that shares the most recent common ancestor with frogs is fishes. False

Classification and Evolution

  • The branch of biology concerned with the naming and classifying of organisms is Taxonomy.
  • Animals that possess homologous structures probably evolved from the same ancestor.
  • The existence of antler-like structures in beetle, fly, and deer species with strong male-male competition is an example of convergent evolution.
  • Which taxonomic category contains all the others listed here? Class.

Cladistics and Character Types

Shared Ancestral Character

In a comparison of birds and mammals, having four limbs is a shared ancestral character.

Domains of Classification

The three domains currently used for classification are Bacteria, Archaea, and Eukarya.

Scientific Naming

The scientific name of the giant swallowtail is Heraclides cresphontes. Therefore, it belongs to the genus Heraclides.

Cladistics Criterion

In cladistics, shared, derived characters are the primary criterion used to classify organisms.

Defining Ancestral Characters

A shared ancestral character is one that is present in the common ancestor and the outgroup.

Prokaryotes and Metabolism

Metabolic Definitions

Some bacteria obtain energy from light (phototrophs), whereas other bacteria obtain energy from chemicals (chemotrophs). Autotrophs (literally “self-feeders”) require only an inorganic substance, such as carbon dioxide, as their carbon source; heterotrophs (literally “other-feeders”) require at least one organic nutrient as their carbon source.

Prokaryotic Characteristics

  • Which of the following is LEAST associated with the others? Binary fission.
  • Prokaryotes accumulate new mutations quickly because they have short generation times and large population sizes.
  • Which structure does a prokaryote not have? A nucleus.
  • Prokaryotes reproduce asexually by binary fission.

Plant Life Cycles and Reproduction

Meiosis in Sexual Reproduction

Question: Which statement is true for all sexually reproducing plants and animals? Answer: The process of meiosis produces haploid cells.

Ploidy Levels

Which structures are haploid? Egg, Gametophyte, Spores.

  • The embryo is diploid.
  • The sporophyte generation is diploid.
  • The gametophyte generation is haploid.
  • The megaspore is haploid.

Mosses and Ferns (Seedless Plants)

  • In moss, antheridia produce sperm.
  • The sperm produced by mosses require moisture to reach an archegonium.
  • In mosses gametes are produced by mitosis; in ferns gametes are produced by mitosis.
  • Where do fern antheridia develop? On the underside of the gametophyte.
  • The conspicuous part of a fern plant is a diploid sporophyte.

Gymnosperms (Seed Plants)

  • Which structure contains multiple gymnosperm ovules? Ovulate cone.
  • Which structure is found inside a pollen grain? The male gametophyte.
  • What are the main components of a mature gymnosperm seed? Food supply, embryo, and seed coat.
  • Gymnosperms were most abundant during the Mesozoic era.

Angiosperms (Flowering Plants)

  • The male gametophytes of flowering plants are also referred to as pollen grains.
  • In flowering plants, the integuments of the ovule develop into a seed coat.
  • A carpel is composed of the stigma, style, and ovary.
  • A stamen consists of the anther and filament.
  • In angiosperms, pollination is the transfer of pollen grain to the stigma of a flower on the same plant or another plant of the same species.

Plant Evolution and Structure

  • Which taxon is essentially equivalent to the “embryophytes”? Plantae.
  • Apical meristems occur in both roots and shoots of plants.
  • Which of these are spore-producing structures? Sporophyte (capsule) of a moss.
  • The evolution of a vascular system in plants allowed increased height, improved competition for light, and increased spore dispersal distances.
  • The advantages of seeds, compared to spores, include containing a nutrient store for a developing sporophyte.
  • Which event, based on plant fossils, came last (most recently)? Rise and diversification of angiosperms.

Protists, Fungi, and Parasitism

Protist Characteristics

  • All protists are eukaryotic.
  • A porous test (shell) of calcium carbonate, through which pseudopodia protrude, is characteristic of foraminiferans.
  • Which group is matched with a correct anatomical feature? Brown algae → blade.

Parasitic Evasion (Trypanosome)

Trypanosome infections evade attacks by host immune systems through the mechanism of production of new cell-surface proteins with a different molecular structure by each new generation.

Malaria (Plasmodium)

  • Which approach would be most likely to cause evolution of a drug-resistant strain of Plasmodium? Widespread, frequent use of a single drug in patients suffering from malaria.
  • When a mosquito infected with Plasmodium first bites a human, the Plasmodium cells infect the human liver cells.
  • Which process is not an example of consumption in the Plasmodium interaction with mosquitoes and humans? Commensalism.
  • Which form of Plasmodium is the immediate cause of anemia in humans? Merozoites.

Fungi and Ecology

  • Some fungal species live in plants and can kill herbivores that feed on the plant. What type of relationship does this fungus have with its host? Mutualistic.
  • Which of the following best describes the physical relationship of the partners involved in lichens? Photosynthetic cells are surrounded by fungal hyphae.
  • Which feature seen in chytrids supports the hypothesis that they diverged earliest in fungal evolution? Flagellated spores.