Reproduction + Life Cycles
What is the difference between haploid (n) and diploid (2n)?
Haploid cells have one set of chromosomes; diploid cells have two.
What is a hypha?
A filament that makes up the body of a fungus.
What is a sorus?
A cluster of sporangia, usually found on the underside of a fern frond.
What does a phylogenetic tree represent?
A hypothesis about evolutionary relationships among organisms.
Which type of reproduction generally involves only one parent: sexual or asexual?
Asexual
What process reduces a diploid cell to haploid cells?
Meiosis
What is a mycelium?
A network of hyphae.
What is produced inside a fern sporangium?
Haploid spores.
On a phylogenetic tree, what does a node represent?
A common ancestor.
What are the three domains of life?
Bacteria, Archaea, and Eukarya.
What is the difference between a gamete and a spore?
A gamete fuses with another gamete during fertilization; a spore can develop into a new organism without fusing with another cell.
What does "dikaryotic" mean?
A cell contains two unfused haploid nuclei.
What's the difference between a gametophyte and a sporophyte?
A gametophyte is haploid and produces gametes; a sporophyte is diploid and produces spores.
What makes a group monophyletic?
It contains a common ancestor and all of its descendants.
Name two ways that Bacteria and Archaea can exchange genetic material without sexual reproduction.
Transformation, transduction, or conjugation.
A gametophyte is haploid. It produces gametes. Should it use mitosis or meiosis and why?
Mitosis, because the gametophyte is already haploid and needs to maintain that chromosome number.
What's the difference between being dikaryotic and being diploid?
Dikaryotic means two separate haploid nuclei; diploid means one nucleus containing two sets of chromosomes.
Where would you find the archegonia and antheridia on a Ceratopteris gametophyte?
Archegonia are near the notch; antheridia are along the margin of the thallus
Two organisms that appear next to each other on a phylogenetic tree are always the most closely related. Is this true/false, and why?
False. Relationships are determined by their most recent common ancestor, not simply by how close they look on the page.
Which of these organisms has a haploid-dominant life cycle: humans, fungi, or most animals?
Fungi
Put these in the correct order for a plant life cycle: gametophyte, spore, zygote, sporophyte, gamete.
Sporophyte → spore → gametophyte → gamete → zygote → sporophyte
Two fungal mating strains undergo conjugation. What is the significance of eventually forming a diploid stage?
It allows genetic material from two parents to combine, increasing genetic variation in sexually produced offspring.
Why do ferns need water for sexual reproduction?
Their sperm are flagellated and need a film of water to swim to the archegonium/egg.
Put these taxonomic ranks in order from broadest to most specific: species, family, domain, genus, class, order, phylum, kingdom.
Domain → Kingdom → Phylum → Class → Order → Family → Genus → Species
An organism has a multicellular haploid stage and a multicellular diploid stage. It produces spores from its diploid stage and gametes from its haploid stage. What type of life cycle is this?
Alternation of generations, characteristic of plants and some algae.