Biology - Exam 1 questions and answers
***-What are features shared by land plants, those in the group Plantae? Another way to think about answering this question is to recall our discussion about what features plants might need on land. Recall that we talked about advantages of living on land over vs. in water and we talked about physiological challenges that plants needed to overcome to live on land. (CH 29)
-All land plants share the following characteristics: alternation of generations, with the haploid plant called a gametophyte, and the diploid plant called a sporophyte; protection of the embryo, formation of haploid spores in a sporangium, formation of gametes in a gametangium, and an apical meristem.
-In general, what is meant by a life cycle with alternation of generations? You may want to include definitions of sporophyte, gametophyte, spore, and zygote in your definition. -Which parts of the life cycle have diploid and haploid cells? (CH 28)
-Alternation of generations is a type of life cycle found in terrestrial plants and some algae in which subsequent generations of individuals alternate between haploid and diploid organisms. A sporophyte is the diploid multicellular stage in the life cycle of a plant or alga. Gametophyte is the haploid stage in the life cycle. A spore is a unit of sexual or asexual reproduction that may be adapted for dispersal and for survival. A zygote is the cell formed by the union of a male sex cell (a sperm) and a female sex cell (an ovum). -It starts with haploid gametes then when they fuse, they turn into diploid gametes.
-Once on land, animals had two major modes of living. How do Amphibians and Amniotes live on land? -What are their major differences? (CH 32, 33, 34)
-Amphibians tied to water for breeding; Amniotes lay eggs on land and have waterproof skin.
-What are the three major types of animal body symmetries? Explain or illustrate each. (CH 32, 33, 34)
-Asymmetrical, Radial Symmetry, Bilateral Symmetry (describe each briefly)
***-What are the key differences between members of the groups Bacteria and Archaea? In your answer you may what to discuss cellular structures and ecological differences. -In general what is meant by "Gram Positive" vs. "Gram Negative" prokaryotes? (CH 27)
-Both bacteria and archaea have different Ribosomal RNAs (rRNA). Archaea have three RNA polymerases like eukaryotes, but bacteria have only one. Archaea have cell walls that lack peptidoglycan and have membranes that enclose lipids with hydrocarbons rather than fatty acids. -Gram positive bacteria have a thick peptidoglycan layer and no outer lipid membrane whilst Gram negative bacteria have a thin peptidoglycan layer and have an outer lipid membrane.
***-Generalize about features present in members of Bryophyta (the non-vascular land plants). -How are they different from seedless vascular plants and seed plants? Common names of members of Bryophyta include: Liverworts, Hornworts and Mosses. YOU DO NOT NEED TO INCLUDE ALL MEMBERS AS EXAMPLES IN YOUR ANSWERS. (CH 29)
-Bryophytes are an informal group consisting of three divisions of non-vascular land plants: the liverworts, hornworts and mosses. They are characteristically limited in size and prefer moist habitats although they can survive in drier environments. The bryophytes consist of about 20,000 plant species. -Bryophytes lack true vascular system, i.e. xylem and phloem. Vascular plants have true xylem and phloem. Alternation of generations of sporophytic and gametophytic generation occurs in both. In Bryophytes, main plant is gametophyte and sporophyte is reduced and parasitic on gametophyte, whether complete or partial.
-What are the three major "body types" or cellular shapes exhibited by prokaryotes? Describe each briefly. (CH 27)
-Cocci (spherical), bacilli (rod-shaped), and spirilli (spiral-shaped)
-Generalize about features present in members of the protist group SAR. -What separates them from other protists anatomically and ecologically? Common names of members of the group are: Diatoms, Golden Algae, Brown Algae, Dinoflagellates, Apicomplexans, Ciliates, Radiolarians, Forams, and Cercozoans. YOU DO NOT NEED TO INCLUDE ALL MEMBERS AS EXAMPLES IN YOUR ANSWERS. (CH 28)
-Contains a large, extremely diverse collection of protists from three major subgroups: stramenopiles, alveolates, and rhizarians. -They have DNA similarities. The members of this clade also include species with membrane bound sacs (alveoli) just under the plasma membrane.
-What feeding mode did filter-feeding early fishes adopt? How did it change the vertebrate body plan? (CH 32, 33, 34)
-Fishes became predatory: jaws, teeth, improved senses, paired fins came along as a result of predatory life.
-Describe Fungi in general. -What similarities and differences are there among fungi, animals and land plants? -Where do Fungi live? -How do Fungi make a living? (CH 31)
-Fungi are eukaryotic organisms. Most fungi consist of hyphae, which combine to make up the fungal mycelium. -their trophic level, their place in the food chain. Neither fungi nor animals are producers as plants are. Both must use external food sources for energy. Fungi and animals share a molecule called chitin that is not found in plants. -Most fungi live in either soil or dead matter, and many are symbionts of plants, animals, or other fungi. -Fungi can reproduce sexually or asexually by spores that grow from hyphae.
***-What is the developmental pathway for most animal groups? -What is a Zygote, Blastula, Gastrula, Archenteron. What is Gastrulation? -What are the first two Embryopnic Germ Layers? -What is the major difference between Protostomes and Deuterostomes? (CH 32, 33, 34)
-Gametes-->fertilization-->zygote-->cell cleavage-->blastula-->blastopore formation-->gastrula-->gastrulation -complete when gut (archenteron) fully formed. -Ectoderm and Endoderm. -Protostomes (mouth to anus), Deuterstomes (anus to mouth)
-What are the key differences and similarities among Homospory and Heterospory. Recall that most early land plants are Homosporous and there was a revolution in reproduction within the seedless vascular plants which lead to Heterospory to become the rule among land plants like Gymnosperms and Angiosperms later. (CH 29)
-Homospory is the production of a single type of spores. Heterospory is the production of two types of spores different in size as well as in sex
-Generalize about features present in members of the protist group Unikonta (excluding Fungi and Animals). -What separates them from other protists anatomically and ecologically? Common names of members of the group are: Slime Molds, Tubulinids, Entamoebas, Nucleriids, and Choanoflagellates. YOU DO NOT NEED TO INCLUDE ALL MEMBERS AS EXAMPLES IN YOUR ANSWERS. (CH 28)
-It consists of amoebozoa and opisthokonts. They have a single emergent flagellum, or are amoebae with no flagella. -They have animals, fungi, and related forms, which makes it more recent.
-What is Mesoderm? How and where does it form in animal embryos? -What is the difference among Acoelomates, Pseudocoelomates and Coelomates? (CH 32, 33, 34)
-Mesoderm--third embryonic germ layer; -Acoelomates-solid mesoderm; Pseudocoelomates-fluid-filled space between mesoderm and endoderm; Coelomate-fluid-filled space within the mesoderm
-As adaptations why did land plants develop seeds and pollen? In other words, how are seeds and pollen adaptations to deal with environmental challenges in the evolution of later land plant groups like Gymnosperms and Angiosperms? (CH 30)
-Pollen and seed were innovative structures that allowed seed plants to break their dependence on water for reproduction and development of the embryo, and to conquer dry land. to be able to be pollinated
-How do prokaryotes reproduce asexually? -How to prokaryotes reproduce in a manner similar to (but not the same as) sexually reproducing eukaryotes? You may find it useful to include definitions of "transformation," "transduction," and "conjugation" in your answer to the second question. (CH 27)
-Prokaryotes reproduce asexually by binary fission; they can also exchange genetic material by transformation, transduction, and conjugation. -In transformation, a bacterium takes up a piece of DNA floating in its environment. In transduction, DNA is accidentally moved from one bacterium to another by a virus. In conjugation, DNA is transferred between bacteria through a tube between cells.
(Bonus Question) What are some impacts (positive or negative) on humans and human society of prokaryotes?
prokaryotes live in symbiosis with the human body, which means they exist in a mutually beneficial relationship
-There are four major groups of Fungi that we discussed. Describe the features of three of these groups—how do the groups differ anatomically, by life cycle, or ecologically? Common names of the major groups of Fungal groups include: Chytrids, Zygomycetes, Glomeromycetes, Ascomycetes, and Basidiomycetes. YOU DO NOT NEED TO INCLUDE ALL MEMBERS AS EXAMPLES IN YOUR ANSWERS. (CH 31)
Chytridiomycota (chytrids): lots single celled, have flagellated spores, decomposers, symbionts, parasites, hydrothermal vents -Zygomycota (bread molds): molds, decomposers, quick growth, can lie dormant in soils -Ascomycota (yeasts and sac fungi): "cup fungi", spores in sac (cup)-like asci, large and above ground spore producing structures, yeast to morels and truffles -Basidiomycota (club fungi): many with long-lived dikaryotic mycelia, mushrooms, basidoiocarps; gills under cap with basidia that produce basido spores
(Bonus Question) What are some impacts (positive or negative) on humans and human society of Fungi?
Fungi create harm by spoiling food, destroying timber, and by causing diseases of crops, livestock, and humans.
***Generalize about anatomical differences between the two largest groups of Angiosperms—the Monocots and the Eudicots. (CH 30)
Monocots: one cotyledon, veins usually parallel, vascular tissue scattered, root system usually fibrous (no main root), pollen grain with one opening, floral organs usually in multiples of 3 Eudicots: two cotyledons, veins usually netlike, vascular tissue usually arranged in a ring, taproot (main root) usually present, pollen grain with three openings, floral organs usually in multiples of four or five
(Bonus Question) What are some impacts (positive or negative) on humans and human society of Bryophytes?
Present uses of bryophytes include ecology, horticulture, construction, household uses, medicine and even food. mosses can be used as an indicator of calcium and nutrient content in water.
(Bonus Question) What are some impacts (positive or negative) on humans and human society of Protists (single-celled eukaryotes)?
Some protists are important as disease vectors. For example, amebic dysentery is a serious illness that affects and kills humans. The protist Plasmodium falciparum causes malaria is a disease that kills millions of people every year in the tropics and is carried by Anopheles mosquitoes.
(Bonus Question) What are some impacts (positive or negative) on humans and human society of Invertebrate Animals (not Chordates)?
Some species of invertebrates are brilliant aerators of soil as well as creating it. In other words, invertebrates not only help us to grow food crops through pollination, they help create and maintain soil quality.
What are the basic, defining features of animals? (CH 32, 33, 34)
Heterotrophic, Eukaryotic, Motile, Unikonta, Opisthokont
-What is a monophyletic group? -What is the significance of taxonomists including only monophyletic groups in biological classification? -It is not a requirement, but perhaps in your answer you would like to include a discussion of paraphyletic and polyphyletic groups. (CH 26)
-A monophyletic group, or clade, is a group of organisms that consists of all the descendants of a common ancestor. -A monophyletic taxon is one that includes a group of organisms descended from a single ancestor , whereas a polyphyletic taxon is composed of unrelated organisms descended from more than one ancestor. -A paraphyletic group consists of all of the descendants of a common ancestor minus one or more monophyletic groups. A polyphyletic group is characterized by convergent features or habits of scientific interest.
-What is a phylogeny? -What does it depict? -How is time read on a phylogeny? -Illustrate the following aspects of a phylogeny and discuss what each means from a biological perspective: root, branches, node, living taxa, extinct taxa. (CH 26)
-A phylogeny is an evolutionary tree and classification and diversification of species or groups of organisms. -It represents evolutionary relationships among a set of organisms or groups of organisms, called taxa. -Time is read from the bottom to the top, the bottom is the oldest and the top is the newest or most recent. -The root of the tree represents the ancestral lineage, and the tips of the branches represent the descendants of that ancestor. The "tips" of the tree branches represent the taxa in the study. The nodes on the tree represent the common ancestors of those descendants. Extinct taxa are not aligned at the present time.
***-Generalize about features of members of the seedless vascular plants. -How are they different from Bryophytes and seed plants? -What is Xylem, Phloem and Lignin? Common names of members of this group include: Lycophytes, Ferns, Horsetails and Whisk Ferns. YOU DO NOT NEED TO INCLUDE ALL MEMBERS AS EXAMPLES IN YOUR ANSWERS. (CH 29)
-Seedless vascular plants are plants that contain vascular tissue, but do not produce flowers or seeds. In seedless vascular plants, such as ferns and horsetails, the plants reproduce using haploid, unicellular spores instead of seeds. -The major difference between bryophytes and vascular plants is the lack of specialized structures to carry water and nutrients in bryophytes. This means that water and nutrients must be dispersed via diffusion to the tissues of bryophytes, which requires them to remain small. -Xylem is a tissue consisting of dead, hollowed-out cells that form a system of pipes. Phloem is the vascular tissue in plants that conducts sugars and other metabolic products downward from the leaves. Lignin is a chemical compound derived from wood and is found in the secondary cell walls of plants.
Define the following terms: -Taxonomy, -Biological Classification, -Systematics. (Ch 26)
-Taxonomy: the branch of science concerned with classification, especially of organisms; systematics. -Biological Classification is the science of naming, defining and classifying groups of biological organisms on the basis of shared characteristics. -Systematics: the branch of biology that deals with classification and nomenclature; taxonomy.
***-Describe the features and a generalized life cycle of an Angiosperm. -Why were flowers and fruits key adaptations for Angiosperms? -Evolutionarily what occurred over time between Angiosperms and the species of animals that pollinated their flowers, ate their fruits, and dispersed their seeds? Common names of the major groups of Angiosperms include: Water Lilies, Magnolias, Monocots and Eudicots. YOU DO NOT NEED TO INCLUDE ALL MEMBERS AS EXAMPLES IN YOUR ANSWERS. (CH 30)
-The adult, or sporophyte, phase is the main phase in an angiosperm's life cycle. Like gymnosperms, angiosperms are heterosporous. They produce microspores, which develop into pollen grains (the male gametophytes), and megaspores, which form an ovule containing the female gametophytes. -Angiosperms produce their gametes in separate organs, which are usually housed in a flower. The surrounding tissues of the ovary thicken, developing into a fruit that will protect the seed and often ensure its dispersal over a wide geographic range.
-Generalize about features present in members of the protist group Archaeplastida (excluding land plants). -What separates them from other protists anatomically and ecologically? Common names of members of the group are: Red Algae, Chlorophytes, and Charophytes (non-land plants). YOU DO NOT NEED TO INCLUDE ALL MEMBERS AS EXAMPLES IN YOUR ANSWERS. (CH 28)
-The cells of the Archaeplastida typically lack centrioles and have mitochondria with flat cristae. They usually have a cell wall that contain cellulose, and food is stored in the form of starch. -They lack centrioles, but other groups do not
-Describe the features and a generalized life cycle of a Gymnosperm. -What does the word Gymnosperm mean literally? -Why is this a good word to describe Gymnosperms? Common names of members of this group include: Cycads, Gingkos, Gnetopytes, and Conifers. YOU DO NOT NEED TO INCLUDE ALL MEMBERS AS EXAMPLES IN YOUR ANSWERS. (CH 30)
-The gymnosperm life cycle has a dominant sporophyte generation. Both gametophytes and the next generation's new sporophytes develop on the sporophyte parent plant. Each female gametophyte produces an egg inside an ovule. Pollination occurs when pollen is transferred from a male to female cone. -It means "naked seed" -no true fruits, included conifers
-Summarize the various nutritional and metabolic habits exhibited by prokaryotes. In other words, what are the ways in which prokaryotes obtain energy and carbon? Table 27.1 of your text will be enormously helpful to answer this question. -It might be helpful to include definitions of the following terms in your answer: photoautotroph, chemoautotroph, photoheterotroph, and chemoheterotroph. (CH 27)
-They may get energy from light (photo) or chemical compounds (chemo). They may get carbon from carbon dioxide (autotroph) or other living things (heterotroph). Most prokaryotes are chemoheterotrophs. -Photoautotrophs: organisms that can make their own energy using light and carbon dioxide via the process of photosynthesis -Chemoautotroph: an organism, typically a bacterium, which derives energy from the oxidation of inorganic compounds. -Photoheterotroph: organism that uses light for energy, and cannot use carbon dioxide as their sole carbon source -Chemoheterotroph: derives its energy from chemicals, and needs to consume other organisms in order to live
-Generalize about features present in members of the protist group Excavata. -What separates them from other protists anatomically and ecologically? Common names of members of the group are: Diplomonads, Parabasalids, and Euglenozoans. YOU DO NOT NEED TO INCLUDE ALL MEMBERS AS EXAMPLES IN YOUR ANSWERS. (CH 28)
-defined by an asymmetrical appearance with a feeding groove that is "excavated" from one side; it includes various types of organisms which are parasitic, photosynthetic and heterotrophic predators. -They are the oldest group of protists with animals being the newest.
***-Summarize the life cycle of most Fungi. -How is it similar and different from the alternation of generations in the average plant life cycle? -In the both life cycles, where are the haploid and diploid phases of life? -Where are asexual and sexual aspects of reproduction in each life cycle? (CH 31)
-life cycle involves the fusion of hyphae from two individuals, forming a mycelium that contains haploid nuclei of both individuals -Fungi spend most of their life cycle in the haploid state. They form diploid cells only during sexual reproduction. But fungi are unique in having cell walls made of chitin instead of cellulose -In the life cycle of a sexually reproducing fungus, a haploid phase alternates with a diploid phase. The haploid phase ends with nuclear fusion, and the diploid phase begins with the formation of the zygote. plants go through both. The haploid stage, in which a multicellular haploid gametophyte develops from a spore and produces haploid gametes. -Asexual spores are genetically identical to the parent and may be released either outside or within a special reproductive sac called a sporangium. Adverse environmental conditions often cause sexual reproduction in fungi. Plants reproduce sexually through the fusion of male and female gametes in the flower. Asexual reproduction is through stems, roots and leaves
-What are the chief differences between prokaryotes and single-celled eukaryotes (protists)? -How do we think that endosymbiosis played a role in the evolution of simple, single-celled eukaryotes (protists) from prokaryote ancestors? (CH 28)
-more complex cells, has nucleus, endoplasmic reticulum, golgi body, diverese ecologically -prokaryotes adapted to photosynthesize