Chapter 38 - Angiosperm Reproduction and Biotechnology

Environmental signals

________, such as temperature or illumination changes, are frequently required to break dormancy.

Carpels

________ and stamens are sporophylls- reproduction- specialized modified leaves; sepals and petals are sterile modified leaves.

Stamens

________ produce anthers, which contain haploid microspores that mature into pollen grains bearing a male gametophyte.

Hybridization

________ of various plant types and even species is frequent in nature and has been exploited by ancient and modern breeders to introduce new genes into crops.

GM

Genetically modified (________) plants have the potential to improve the quality and quantity of food available throughout the world, as well as play a growing role in biofuel production.

Flowers

________ are fixed stems that stop growing after the bloom and fruit have developed.

terminal component

The term stamen (microsporophyll) is made up of a stalk called the filament and a(n) ________ called the anther, which contains chambers called microsporangia (polysporangia)

Pollinators

________ are attracted by the petals.

Plants

________ have evolved a variety of mechanisms to avoid self-fertilization, including male and female flowers on separate individuals, nonsynchronous production of male and female parts within a single flower, and self- incompatibility reactions in which pollen grains bearing an allele identical to one in the female are rejected.

stigma

The ________ is a sticky feature at the apex of the style that catches pollen.

meiosis

By ________, the diploid plant, the sporophyte, generates haploid spores.

seeds

The contained ________ are protected by the fruit, which assists in wind dispersal or the attraction of ________- dispersing animals.

Crops

________ are modified through breeding and genetic engineering.

double fertilization

Flowers, ________, and fruits are all essential components of the angiosperm life cycle.

petals

Sepals, ________, stamens, and carpels are the four floral organs.

angiosperm life cycle

The ________ is characterized by flowers, double fertilization, and fruits.

Mitosis

________ divides these spores, resulting in multicellular gametophytes, the male and female haploid plants that generate gametes (sperm and eggs)

pollination

Following ________, the pollen tube releases two sperm into the female gametophyte.

sexual reproduction

Flowers, which are generated by the sporophyte, are used for ________.

Angiosperm reproduction

________ is characterized by a generational switch between a multicellular diploid sporophyte generation and a multicellular haploid gametophyte generation.

Carpels

________ make up the first (innermost) whorl, stamens make up the second, petals make up the third, and sepals make up the fourth (outermost) whorl.

pollination

Following ________, the pollen tube releases two sperm into the female gametophyte.