ACTIVITY 8 THE REPRODUCTIVE ORGANS OF PLANTS: FLOWERS

angiosperms

The ________________ are regarded as the most numerous and most diverse members of Kingdom Plantae.

One of its characteristic feature is the grouping of reproductive structures with sterile auxiliary parts into a single unit known as the flower.

four whorls; sepals; petals; stamen; pistil

Being a compact shoot system, a flower is primarily made up of _______ ________. Starting from outermost to innermost- _________, __________, __________ and ___________.

sepal

__________, any of the outer parts of a flower that primarily serve to enclose and protect the unopened flower bud and sometimes used to attract pollinators.

the same

Although flowers vary greatly in appearance, they contain __________ floral whorls.

Flowers serve as the seat for meiosis and fertilization – two key processes in sexual reproduction.

whorl

A __________ in flowers refers to a circular arrangement of similar plant parts—such as sepals, petals, stamens, or carpels—radiating from a single point around the stem.

calyx; corolla

All members of a whorl of floral parts together form a group or unit. For these, we use collective terms. The __________ is a collective term for all the sepals of a flower. All the petals of a flower collectively form the __________.

polypetalous; gamopetalous

The petals may be free from one another (_____________) or exhibit some degree of fusion or union (_______________). When petals are united, you will be amazed at the different shapes of the corolla like being funnelshaped, bell-shaped, star-shaped and the like.

regular; actinomorphic

A flower where the petals are similar in terms of size and shape is a ___________ flower. Regular flowers exhibit radial symmetry (__________). A flower with radial symmetry has more than two dividing lines that can be used to divide a flower into symmetrical halves.

irregular; zygomorphic

If one petal will be different from the other, then it is an _________ flower. Irregular flowers show bilateral symmetry (_____________). A flower with bilateral symmetry has only a ingle dividing line that produces symmetrical halves.

perianth;

tepals;

petaloid; monocots

The calyx and corolla are sterile and are collectively referred to as the ___________.

When the sepals and petals are not well differentiated from one another and look alike, these are called ___________.

They are usually _________ (petal‐like in color) and this condition is commonly observed in ___________ such as lilies.

filament; anther; androecium

The stamen is composed of a stalk called ___________ and at the tip of the filament is the ____________ that houses the pollen grains. Collectively, stamens are called __________________.

pistil; ovary; style; stigma

The innermost whorl is the __________. The enlarged base is the ___________ where a threadlike structure called ___________ emerges. The tip of the style ends in a globose, sticky structure called ___________.

superior; inferior

superior; inferior

The ovary may be ____________ or ____________ in terms of its position. When the ovary sits on top of the receptacle and the other whorls are inserted below it, then the ovary is ____________. If the ovary is embedded in the receptacle and all the other floral whorls are inserted above it, the ovary is said to be _____________.

receptacle;

complete; incomplete

perfect; bisexual

The reduced stem axis to which all these whorls are attached is called the ___________.

If all these whorls (sepals, petals, stamen, pistil) are present, the flower is said to be ____________. If any of the whorl is missing, the flower is _______________.

A flower that has both pistil and stamen is a _____________ flower. Perfect flowers are ___________.

pistil; staminate

stamen; pistillate

unisexual

dioecious; dioecious

If __________ is missing, the flower is imperfect and we can also say, it is a ______________ flower or a male flower. If the _________is missing, it is also imperfect. The flower is said to be _____________ or a female flower. Imperfect flowers are ______________.

A plant with imperfect flowers is ______________ if staminate and pistillate flowers are borne on separate individuals. Papaya plants are ____________

monoecious

It is a _______________ plant if the pistillate and staminate flowers are borne on the same individual. Good example to show this is Zea mays (corn) inflorescence.

inflorescence

peduncle; pedicel

sessile

A flower may be solitary as in Hibiscus rosa-sinensis (gumamela). However, some flowers are borne in clusters called ____________.

The stalk of a solitary flower is called a ___________. If a flower is part of an inflorescence then its stalk is called a ___________.

Flowers that do not have pedicels are said to be __________.

spike

In a __________ inflorescence, the individual sessile flowers are attached on the main axis.

spike

Which type of inflorescence?

catkin

A ____________ is a pendulous inflorescence made of sessile, unisexual flowers.

catkin

Which type of inflorescence?

spadix; spike; spathe

In family Araceae (aroid or gabi family), their ________ inflorescence is made up of a thickened fleshy axis bearing clusters of sessile flowers (________) that are apetalous and unisexual. The thickened axis is usually enclosed by a ______________ that are variously colored.

spadix

Which type of inflorescence?

raceme

A ____________ inflorescence has individual pedicellate flower attached on an elongated axis.

raceme

Which type of inflorescence?

panicle

When a raceme becomes branched, this is now known as ___________ inflorescence.

panicle

Which type of inflorescence?

umbel

In an __________, the pedicels all arise from a common point, giving a flat-topped appearance of the whole inflorescence.

umbel

Which type of inflorescence?

corymb

A ____________ is a flat‐ or round‐topped inflorescence formed by lateral, stalked flowers with progressively shorter stalks. Here, the outer flowers open ahead of the inner ones.

corymb

Which type of inflorescence?

cyme

In a ___________ inflorescence, pedicels arise at different points, the lower pedicel being longer than the upper ones, thus the inflorescence appears to be flat-topped. However, the inner flowers open ahead of the outer flowers.

cyme

Which type of inflorescence?

head; ray; disk

Look closely at any sunflower or daisy or its relatives. The apparent flower is a composite of many small flowers. The composite or __________ inflorescence characteristic of Asteraceae (sunflower family) is made up of 2 types of florets – the _____ and _______ florets. Both florets vary in color depending on the species.

head

Which type of inflorescence?

ray; disk; pappus; seed dispersal; involucre

composite or head inflorescence

The ________ florets around the periphery look like petals that serve to attract pollinators. The _________ florets in the center function in pollination and seed production. The calyx of each floret persists and becomes a highly modified ___________ which aids in _____________.

The _____________ is a whorl of bracts that subtends the whole inflorescence.

phyllaries

The involucre and its bracts called ____________ function like sepals. Do not mistake this with the real sepals specially when you look at the sunflower as a single flower.