7220824
Description
Flashcards by Shareef Akbari, updated more than 1 year ago
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Created by Shareef Akbari
over 7 years ago
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| Question | Answer |
| What are the two major innovations that happened in seed plants? What factor did these innovations arise to combat? | Seeds Pollen Lack of water |
| What does a seed contain? | Embryo Stored food Seed coat |
| What does pollen contain? | Microspore, in which a microgametophyte develops |
| Where do the male and female gametophytes, respectively, develop in seed plants? | Pollen/Seed |
| Are gymnosperms heterosporous or homosporous? | Heterosporous |
| What is endosporic development? | Gametophyte developing inside the spore |
| Which generation is dominant in gymnosperms? | Sporophyte |
| Label this diagram. | |
| What are the advantages of having a seed? | Protection of the embryo Food storage is available |
| List the steps of the evolution of an ovule. | 1. Retention of megaspores within the megasporangium 2. Reduction to a single megaspore mother cell 3. Survival of a single megaspore following meiosis 4. Endosporic development of megagametophyte within the megasporangium 5. Formation of integument that completely envelopes the megasporangium except for a micropyle 6. Modification of the apex of the megasporangium to receive microspores or pollen grains |
| What is a micropyle? | Small opening in the ovule to accept microspores/pollen |
| What is pollen? | Male gametophyte reduced to 2-4 cells that develops into the microspore wall (endospore) |
| What is polinisation | Transport of pollen to the ovule |
| What is anemophily? | Pollinisation by wind |
| What is zoophily? | Pollinisation by birds and mammals |
| What is entomophily? | Polinisation by insects |
| What happens after pollination in Cycadophyta and Ginkophyta? | Pollen tube grows in the nucellus like a parasite. When it is mature, it releases multi-flagellated sperm that swim to egg (needs water) |
| What happens after pollination in Coniferophyta and Anthophyta? | Pollen tube grows slowly to the archegonium and delivers sperm nuclei directly to the egg. No water is needed, sperm has no flagella and no antheridia are produced by the male gametophyte |
| What are the phyla that comprise gymnosperms? | Cycadophyta Ginkophyta Gnetophyta Coniferophyta |
| When did Coniferophyta appear? | In the carboniferous period |
| What did Coniferophyta adapt to? | Cold and dry climate |
| What do the needles come out of in Coniferophyta? | Fasicles |
| What is a fasicle? | Short shoot that has suspended apical meristem activity |
| Why are needles good for dry conditions? | Low surface area means less water loss. Also don't have many stomata. |
| What anatomical part of Coniferophyta are strobili? | Cones |
| Are microsporangiate cones on Coniferophyta on superior or inferior branches? | Inferior |
| Are megasporangiate cones on Coniferophyta on superior or inferior branches? | Superior |
| What cells are microspores formed out of in Coniferophyta? | 2 Prothallalial cells 1 Generative cell 1 tube cell |
| Label this diagram | |
| What are the components of an ovuliferous scale? | 2 ovules and a subtending sterile bract |
| What are the steps that happen before fertilisation in male cones in Coniferophyta? | 1. Microspore mother cells undergo meiosis to turn into pollen grain composed of a tetrad of microspores. 2. Pollen is liberated from microsporangia and carried by the wind 3. Pollen falls on pollination drop which is produced at the micropyle in the archegonia |
| What are the steps that happen before fertilisation in female cones in Coniferophyta? | 1. Megaspore mother cell undergoes meiosis to produce 4 megaspores 2. Megaspore turns into megagametophyte which is not released 3. Functional megaspore undergoes mitosis 4. Fertilization occurs |
| What happens after fertilization in Coniferophyta? | 1. Pollen tube grows and reaches archegonia 2. 2 sperm nuclei are released 3. 1 sperm nucleus fertilizes the egg, the other degenerates. |
| Which part of the seed is from the sporophyte generation? And the gametophyte generation? | Sporophyte generation: Nucellus remnants and seed coat. Embryo Gametophyte generation: Megagametophyte (storage tissue) |
| What do Cycadophyta look like? | Palm trees |
| How are Cycadophyta pollinated? | Entomophily |
| Can Cycadophyta symbiose with anything? If so, what? | Yes Cyanobacteria |
| What does dioecious mean? | Plants are not hermaphroditic |
| Where are the cones located in cycadophyta? | At the end of stems |
| Are Cycadophyta sperm flagellated or not? | They are. |
| Do Cycadophyta have wood? | Yes |
| What is the only species in Ginkophyta? | Maidenhair Tree |
| What are the characteristics of Ginkophyta? | Large Temperate Deciduous Dioecious Fan-like leaves |
| What is unique about ginkophyta? | Kiterpene Ginkolide that has medicinal uses |
| Where does pollination happen in Ginkophyta? | On the tree. |
| Where does fertilization happen in Ginkophyta? | On the ground |
| What genera compose Gnetophyta? | Ephedra Welwitschia Gnetum |
| What characteristics do Gnetophyta and angiophyta share? | Some cones look like flowers Tracheids AND vessel elements No archegonia in Welwitschia and Gnetum |
| What is pseudo-double fertilization? | When 2 sperm fertilize 2 eggs and make 2 embryos. |
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