Why are seeds such a significant evolutionary innovation? (a) Describe a conifer
ID: 169150 • Letter: W
Question
Why are seeds such a significant evolutionary innovation? (a) Describe a conifer pollen cone. Why is it a simple strobilus? (b) Describe a conifer seed cone. Why is it a compound strobilus? Describe how a pine leaf (needle) is suited to growth under arid conditions. Determine if the following statements are true or false. T F In pine, the seed-scale complex consists of an ovuliferous scale and a sterile bract. T F In pine, the generative cell divides to form megaspores. T F In pine, the integuments develop into the seed coat and the ovule develops into the seed. T F In pine, the megaspores are produced in the megasporangium by mitosis before pollination. T F The male cones in pines are woody, perennial and produce pollen in the spring for several years. T F The life cycle of pines is usually completed in one year or less. T F All seed plants are heterosporous. T F The conifers, gnetophytes, cycads, and Ginkgo all have free-swimming sperm. T F In pines pollen is carried from the microsporangiate cone to the ovulate cone by insects. T F The nucellus is a type of megasporangium.Explanation / Answer
7.seed is the best evolutionary benefit of plants as it is associated with plant reproduction and having several advantages. as- the evolution of seeds lowered the depency of plants to water for reproduction. seed contains embryo that can remain dormant at adverse condition and germinate as diploid sporophyte.as seed can be dispersed by wind, animal,water or by any mechanical method it reduces the competition for reproduction and it also increases the efficiency of new plant growth.
a.conifer pollen cone- female cone produces seed and male cone pollen. most conifer bear male and female cone on same plant these plant known as gymnosperm and pollination by wind. pollen grain in pinophyte produces pollen tubes, when pollen grain land near female gametophyte it undergo meiosis,and produces zygote which later develops in embryo.
a strobilus is a structure found in land plants. it consist of sporangia bearing structure densely aggregated along the stem. strobili are often called cones.
Related Questions
drjack9650@gmail.com
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.