Many aspects of the angiosperm life cycle make flowering plants particularly well-suited to life on land. In fact, angiosperms are the most diverse and widespread of all plants. In angiosperms, a gametophyte protects a dependent sporophyte from desiccation. |
Flowers attract animal pollinators carrying pollen from other plants of the same species Fruits aid in the dispersal of seeds by wind or by animals that carry or eat the fruits. In many angiosperms, the male gametophyte contained in a pollen grain can be transported many miles away by wind or animal pollinators. Floral parts of the sporophyte protect the reduced female gametophyte from drying out and from UV radiation. Seeds protect and nourish plant embryos, and fruits protect the seeds. Seeds enable plant embryos to be dispersed long distances from the parent plant via wind or animals |
the order of pollination, fertilization and seed development |
1. pollen grain lands on stigma 2. pollen tube grows down the style 3. generative cell divides, forming two sperm 4. two sperm are discharged into the female gametophyte 5. sperm fuse with the egg and two polar nuclei 6. zygote forms and divides into a terminal cell and a basal cell 7. cells of embryo differentiate into three tissue types 8. seed dries out and becomes dormant |
Why do fleshy fruits often have seeds with very tough seed coats? So the seeds can extend the distance they travel by catching breezes |
So the seeds can survive the mechanical forces and conditions in an animal's gut |
What characterizes the fruit of seeds that are dispersed by the wind? They are very fleshy. |
They have structures to extend the distance they travel on the wind. |
True or false? Fruits provide food to the developing plant. |
F |
Which part of a flower develops into the seed? Endosperm cell |
Ovule |
Which term describes the portion of a peach that can be eaten by humans? |
Pericarp |
True or false? The endosperm tissue that nourishes the developing plant has the same nutritional characteristics regardless of the plant species. |
F |
Which part of a plant attracts pollinators? |
Petals |
Which process involves the transfer of pollen grains from an anther to a stigma? |
Pollination |
True or false? The endosperm in a seed develops into the embryo. |
F |
Which term describes the male gametophytes of flowering plants? |
Pollen grains |
Which structure formed by the male gametophyte allows sperm to reach the ovary of a flowering plant? |
Pollen tube |
How is fertilization in flowering plants different from fertilization in other plant groups? One sperm nucleus fuses with the egg to form a diploid zygote, whereas the other sperm nucleus fuses with two polar nuclei to form a cell that develops into endosperm. |
One sperm nucleus fuses with the egg to form a diploid zygote, whereas the other sperm nucleus fuses with two polar nuclei to form a cell that develops into endosperm. |
Which of the following statements about seed formation in a flowering plant is true? The swellings that develop into cotyledons are located at the end of the embryo on top of the row of single cells. |
The swellings that develop into cotyledons are located at the end of the embryo on top of the row of single cells. |
What is endosperm? the leaves that are a part of the embryo |
via cotyledons, a source of food for the embryo |
Fruits evolved primarily as structures specialized to _____. |
disperse seeds |
Meiosis will produce microspores in the _____. (Concept 38.1) |
anther |
Which association below is correct? (Concept 38.1) unisexual flowers ... dioecious |
dioecious ... separate female and male plants |
In angiosperms, each pollen grain produces two sperm. What do these sperm do? (Concept 38.1) One fertilizes an egg, and the other fertilizes the fruit. |
One fertilizes an egg, and the other combines with a cell that develops into stored food. |
The germination of seeds _____. (Concept 38.1) depends on maturation of the embryo |
depends on imbibition |
Which of the following is a method of vegetative reproduction? (Concept 38.2) |
All of the above. |
Which of the following is an advantage of asexual reproduction in plants? (Concept 38.2) |
Both of the following are correct: No need for a pollinator; More robust offspring. |
Self-incompatibility _____. (Concept 38.2) is based on the same mechanism of transplant rejection seen in animals |
maintains variation |
In grafting, the plant that provides the root system is the _____ and the twig is the _____. (Concept 38.2) |
stock ... scion |
Which of the following is a possible advantage of biofuels? (Concept 38.3) The amount of energy used to produce biofuels will be more than they yield. |
The CO2 produced by biofuels will be absorbed by the crops used to produce them, creating a carbon-neutral cycle. |
Which example below is a concern related to the debate over plant biotechnology? (Concept 38.3) introduced genes leading to the creation of "superweeds" |
All of the above. |
Evergreen trees lose their leaves _____. |
steadily all year |
The breakdown of chlorophyll reveals the _____ pigments of a leaf. |
carotenoid |
The formation of the abscission layer cuts off transport of substances to and from the leaf. As the concentration of sugar trapped within a leaf increases, _____ pigments are produced. |
anthocyanin |
The protective layer that forms between the abscission layer and the stem consists of _____. densely colored cells filled with a waxy layer |
densely colored cells filled with a waxy layer |
After leaf abscission, growth will resume from the _____. |
axillary bud |
_____ trees lose their leaves in preparation for winter. |
Deciduous |