1. Gymnosperms used to dominate the natural landscapes in the early (Triassic) and middle (Jurassic) Mesozoic era. However, today, in countries like Botswana they do not exist naturally. Based on their characteristics, explain at least 3 reasons why they have disappeared in these area and many other parts of the world.

1. Gymnosperms used to dominate the natural landscapes in the early (Triassic) and middle (Jurassic) Mesozoic era. However, today, in countries like Botswana they do not exist naturally. Based on their characteristics, explain at least 3 reasons why they have disappeared in these area and many other parts of the world.

Biology: The Dynamic Science (MindTap Course List)

4th Edition

ISBN:9781305389892

Author:Peter J. Russell, Paul E. Hertz, Beverly McMillan

Publisher:Peter J. Russell, Paul E. Hertz, Beverly McMillan

Chapter28: Seedless Plants

Section: Chapter Questions

Problem 6TYK: In addition to having simple vascular tissue, seedless vascular plants differ from all bryophytes in...

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Which of the following traits characterizes gym nosperms? The plants carry exposed seeds on modified leaves Reproductive structures are located in a flower After fertilization, the ovary thickens and forms a fruit The gametophyte is the longest phase of the life cycle.
1. Based on the readings you encountered in the course about gymnosperms, in general and cycads, in particular, explain the main morphological, anatomical and reproductive features that could have contributed to the continued survival of their lineages up to the present. 2. Explain the specific morphological, anatomical and reproductive features of cycads that make them more prone (relative to other gymnosperms) to extinction risks from man-made disturbances such as habitat-clearing and poaching. 3. Read the following article about the cycad. Does the Loneliest Plant in the World Need Help?https://www.nationalgeographic.com/science/article/does-the-loneliest-plant-in-the-world-need-help There are two genetics/technology -based interventions mentioned to help save the cycad species. Encephalartos woodii from extinction. What is your reaction to the author’s view about these approaches, do you agree or disagree? What other approaches can you propose to help solve the problem, given that…
1. Differentiate between:a. Homosporous and heterosporous plants b. Sporophyte and gametophyte plants c. Lycopodium and Selaginella 2. Why is Isoetes called quillwort?
III. Gymnosperms - have seeds and vascular tissue (Chapter 18) A. Zamia - live specimen and Figure 18-35 1. To what Phylum does this plant belong? 2. What is unique about where this plant grows? 3. One of the common names for cycads is sago palm. What is one of the major differences between the group that Zamia belongs to and true palms? 4. How is Zamia pollinated?
16. Label the following on Figure 5 below: Antheridia, Archegonia, Adult Sporophyte, Zygote, Egg, Sorus, Gametophyte, Sporangium, Fertilization. Meiosis Spore (n) 917 31 Spore (n) Mature dehiscing (2n) with spores (n) Immature sporangium (2n) Leaf Indusium (2n) Germinating spores (2ń) rhizoids Mature gametophyte prothallus (n) 1n 2n (2n) -Sperm (n) Leaf of a young sporophyte (2n) (n) prothallus (n) 96 (2n) Figure 5. Polystichum life cycle (drawn by Stephanie Preising, SCSU '20) Part B: Psilotum Examine the living Psilotum plant. Psilotum, is unique among living seedless vascular plants because it lacks both roots and true leaves. Note the dichotomous branching pattern of the stems. Instead of roots, Psilotum has an underground stem, a rhizome, which bears rhizoids for the absorption of water. Examine the Psilotum for the presence of sporangia, which are borne terminally on short side branches. Psilotum is homosporous, producing only one type of spore. The spores produce bisexual…
Which of the following traits characterizes gymnosperms? a. The plants carry exposed seeds on modified leaves. b. Reproductive structures are located in a flower. c. After fertilization, the ovary thickens and forms a fruit. d. The gametophyte is longest phase of the life cycle.
Which feature(s) do ferns share with all other land plants? a. sporophyte and gametophyte life cycle stages b. gametophytes supported by a thallus c. dispersal of spores from a sorus d. asexual reproduction by way of gemmae e. water uptake by means of rhizoids.
1. Which of the following created the great coal beds on this planet? * A. the compressed remains of cycads and gymnosperms B. the undecomposed bodies of gymnosperms and dinosaurs C. the remains of the seedless plants of the carboniferous forests D. the compression of great accumulations of peat formed from the anaerobic decomposition of mats of bryophyte 2. Why must bryophytes inhabit damp environment? It is because * A. their sporophyte generation is dependent on the gametophyte. B. their sperm must swim to reach the egg. C. they do not have woody tissues. D. females can produce only one archegonium. 3. Which of the following incorrectly pairs a sporophyte embryo with its food source? * A. Moss embryo-archegonium and gametophyte plant B. Fern embryo-female sporophyte surrounding archegonium C. Pine embryo-female gametophyte tissue in nucellus D. Corn embryo-3N endosperm tissue in seed 4. Which of the…
4. a) EXPLAIN the terms Haplobiontic and Diplobiontic Life Cycle and give ONE example for each b) Anthophytes show "alternation of generation". Identify the structures that represent the TWO stages in its life cycle. c) The diagrams in Figure 2 show the steps in the development of an embryo sac and pollen grain. In ovary megasporangial cell In anther microsporangial cells VI microsporocyte / pollen mother cells (2n) microsporocyte (n) megasporocyte / embryo sac mother cell (2n) 4 megaspores (n) 1 megaspore (..) tube nucleus and VII immature pollen grain antipodal nuclei - polar nuclei synergids egg nucleus .nucleus .nudeus . nudeus (.. VII embryo sac germinating pollen grain FIGURE 2 i) STATE the process that occurs at stages I to IV in the diagrams in Figure 2. ii) What is the chromosome content of the megaspore at III. ii) What are the names of nuclei formed during germination of the pollen grain at VIIIT iv) Identify TWO ways that the sporophyte of a fern differs from that of an…
Seedless Plants Mosses and Other Bryophytes Write True if false 1. Mosses and their relatives belong to a group called Bryophytes 2. Bryophytes stay small because they lack true vascular tissue. 3. The gametophyte is the dominant stage of bryophytes. 4. Bryophytes must live in places where there water for at least part of the year because, for fertilization to occur, eggs must swim. ______________5. A fern is a seedless vascular plant 6. What was the first Plant? 7. Were and how nonvascular plant needs to live? Vascular Plants 8. What is a vascular Plant? 9. What are the advantages of having vascular tissue?
1. During the Triassic and Jurassic period of the Mesozoic era, gymnosperms dominated the land. However, angiosperms are now the more dominant land plants around. How did angiosperms overpower the gymnosperms? Give characteristics of gymnosperms that may have affected their "fitness" to dominate the terrestrial environment.
10. Is the egg cell produced by meiosis or mitosis within an archegonium? Explain Obtain a prepared slide containing mature sporophytes and, using the low power lens of the microscope, find a complete sporophyte. 11. Is the sporophyte haploid or diploid?. Note that the sporophyte is attached to the gametophyte by a large foot. This structure grows through the base of the venter into the storage tissue of the archegonial head. 12. What is the function of the foot? 13. Is the sporophyte an "independent" or "dependent" organism? Explain The sporophyte also consists of a stalk, or seta, and a capsule, or sporangium (see text Figure 16-8, page 371). Numerous spores and elongated elaters are enclosed by the sterile jacket layer of the capsule. The elaters have spirally arranged, hygroscopic (moisture absorbing) wall thickenings that are sensitive to very slight changes in humidity. By twisting with changes in humidity, they aid in spore dispersal (see text Figure 16-12, page 375). Note the…