Video Transcript
Identify the labels on the figure
shown. (A) 1: corolla, 2: stigma, 3:
anther. (B) 1: petal, 2: corolla, 3:
stigma. (C) 1: sepal, 2: anther, 3:
stigma. (D) 1: sepal, 2: style, 3:
stigma. Or (E) 1: corolla, 2: anther, 3:
stigma.
The image provided in the question
shows a flower belonging to an angiosperm, which is a group of plants more commonly
known as flowering plants. Flowers contain the reproductive
organs of angiosperms. And we need to identify the
different parts of this flower that have been labeled. So let’s dive right in. Angiosperm flowers are arranged
into four main whorls that radiate around the stem of the flower. A whorl is each of the set of
organs arranged in successive circular patterns surrounding the stem of an
angiosperm flower. Let’s look at these different
whorls, starting from the exterior of the flower structure.
The outermost whorl is called the
calyx. It’s made up of sepals, one of
which has been labeled on the diagram with a 1. Sepals are small modified green
leaves that protect the flower when it’s in bud. Typically, this bud will eventually
burst open and reveal the other whorls within it. The second outermost whorl is the
corolla whorl. The corolla whorl is made up of
petals, which haven’t been numbered on this diagram, but let’s go ahead and label
one anyway. The corolla is composed of several
brightly colored and often centered petals. Petals are often centered and
brightly colored modified leaves that are especially useful to attract pollinators
like bees.
The third outermost whorl is the
androecium, which includes all the male reproductive organs of the flower. So let’s go ahead and label these
now. The androecium usually consists of
several stamens, which are long filaments with anthers on the top. The anther is responsible for
producing pollen, which contains the male gametes. One anther has been labeled on this
diagram with a 2. The role of the filament is to
support the anther. As they are not numbered on the
diagram, let’s remove the labels for the corolla whorl and the petals it consists of
so that we can label the innermost whorl of the flower.
The innermost whorl is called the
gynoecium, and it contains all the female reproductive organs of the flower. The gynoecium consists of the
carpel. The carpel contains the ovary,
which in turn consists of one or more of ovules. Each ovule tends to contain one egg
cell, which is the female gamete. The carpel also contains a
structure called the style, which leads up from the ovary to a sticky stigma on the
top, which has been labeled in this diagram with a 3. The stigma is responsible for
receiving the male gamete contained within pollen grains. We now have enough information to
answer the question. The correct labels are as follows:
(C) 1: sepal, 2: anther, 3: stigma.
