Plant Hormones Overview

Promotes cell growth, stem growth, root development, and delays leaf drop.

Stimulates stem growth, flowering, and breaks dormancy.

Encourages cell division and prevents leaves from aging.

Slows other hormones and helps plants manage water loss.

Helps fruits ripen and leaves fall off.

Aristotle arranged organisms from simplest to most complex, laying the groundwork for later classification systems.

Leonardo da Vinci recognized fossils as the remains of extinct organisms, challenging the prevailing belief that they were just natural formations.

Lamarck proposed that organisms could pass down characteristics acquired during their lifetime, even though this is not supported by modern genetics.

Epigenetics is the study of heritable changes in gene expression that do not involve mutations in the DNA sequence. These changes can be passed on across generations.

Darwin's theory of natural selection was a major upheaval in our understanding of life, explaining how organisms evolve through time by favoring traits that increase survival and reproduction.

The life cycle stage that starts with a spore and ends with a gamete, containing half the chromosomes of the sporophyte.

The life cycle stage that starts with a zygote and ends with a sporocyte, containing twice the chromosomes of the gametophyte.

The process that changes the sporophyte generation to the gametophyte generation.

The process that changes the gametophyte generation to the sporophyte generation.

The cycle between the sporophyte and gametophyte generations in plants, with each generation playing a distinct role in reproduction.

The exchange of genetic material between homologous chromosomes during prophase I of meiosis. This process creates new combinations of genes and increases genetic diversity.

Meiosis II does not reduce the chromosome number further. Instead, it separates the sister chromatids of each chromosome, resulting in four haploid daughter cells with half the number of chromosomes compared to the original cell.

Meiosis produces four haploid daughter cells, each containing half the number of chromosomes as the original diploid cell. These cells are genetically unique due to crossing-over during Meiosis I.

Meiosis is essential for sexual reproduction. It reduces the chromosome number in gametes, ensuring offspring have the correct number of chromosomes. It also generates genetic diversity by shuffling and recombining genetic information, leading to variation within a population.

Sepals are leaf-like structures that protect the developing flower bud before it blooms. They act as a protective shield, ensuring the delicate flower parts remain safe until they are ready to open.

Petals are the colorful and often fragrant parts of a flower that attract pollinators, such as insects or birds. Their vibrant appearance and enticing scents help ensure that pollen is transferred from one flower to another, allowing for successful fertilization.

The stamen is the male reproductive part of a flower. It consists of two main parts: the filament, a stalk-like structure, and the anther, which produces pollen grains.

The carpel is the female reproductive part of a flower. It is composed of three main parts: the ovary, which contains the ovules, the style, a slender stalk, and the stigma, a sticky surface that receives pollen.

Pollen grains, produced by the stamen, must travel to the stigma of a carpel for fertilization to occur. Pollinators like insects or wind play a crucial role in transporting these pollen grains.

The stamen is the male reproductive part of a flower and produces pollen grains, which are essential for fertilization.

The stigma is the sticky part of the carpel in a flower, responsible for receiving pollen grains and allowing them to germinate, leading to fertilization.