Plant Structures - AP Biology

The cork cambium is a type of secondary meristem tissue found in the periderm. Cork cambium controls lateral growth; specifically, it is the source of secondary epidermis growth.

Cutting into the trunk of a tree to create a horizontal cross section reveals rings, called annual growth rings. These rings show new vascular cambium growth over the course of a year. Differences in growth speed change the size of the growth rings.

The receptacle is the part of an angiosperm out of which the flower grows; thus, the receptacle is at the top of the stem.

The carpel is a part of the female angiosperm reproductive system. The carpel includes the ovary, ovules, style, and stigma. Flowers may have several carpels clustered into a pistil.

Stomata are the pores on the leaves that allow for carbon dioxide to enter and oxygen to leave the leaf. Stroma, thylakoids, and chlorophyll are all components of the chloroplasts.

Stamens are a part of the male reproductive system in angiosperms. Stamens have a filament and an anther, which is attached to the top of the filament. Anthers produce pollen through the process of meiosis.

Chloroplasts are organelles in plant cells that conduct photosynthesis; therefore they are unique to plant cells. All the other mentioned organelles can be found in both animal and plant cells.

Chloroplasts, the site of photosynthesis, are only in plant cells and are not found in animal cells. Ribosomes, a cell membrane, and a mitochondria, however, can be found in both animal and plant cells.

The other structure that may be found in plant cells, but not animal cells, is a cell wall.

The Calvin Cycle occurs in the stroma, the aqueous fluid-filled area of the chloroplast. The stroma can be seen as analogous to the cytoplasm of a cell, in that it is the liquid in which all other substructures reside. The other processes of photosynthesis, the light-dependent reactions, take place in the thylakoid, a membrane-bound substructure within the chloroplast.

Chlorophyll is what gives plants their green color. The chlorophyll located in the chloroplasts captures the light energy that drives the synthesis of food molecules in the chloroplasts—photosynthesis.

Chloroplasts are found mainly in the cells of the mesophyll, which is the tissue in the interior of the leaf. Stomata are the pores that allow carbon dioxide to enter and oxygen to exit the leaf. The stroma is the dense fluid content of the chloroplast.

Chloroplasts are the organelles that contains chlorophyll. Mitochondria produce ATP and are not directly involved in capturing light and photosynthesis. The Golgi apparatus is involved in packaging substances, and Smooth endoplasmic reticulum are involved in lipid production.

A stack of thylakoids is known as granum. Stroma is the region outside the thylakoid membranes, but still inside the chloroplast. Mitochondria is the organelle that produces ATP, and there is no such organelle called thylakoidum.

During the light dependent reaction, protons are pumped from the thylakoid stroma into the lumen. Then, these protons flow down their electrochemical gradient (from high concentration to low concentration), through the ATP synthase protein, producing ATP.

Chlorophyll is used to capture sunlight during the light dependent reaction; the excited electrons then flow down the electron transport chain located on the thylakoid membrane.

During the light dependent reaction, protons are pumped from the thylakoid stroma into the lumen. Then, these protons flow down their electrochemical gradient (from high concentration to low concentration), through the ATP synthase protein, producing ATP.

Cellulose, a polymer of glucose, is the main component of plant cell walls.

Collagen is found in the connective tissues of animals. Chitin is found in the cell walls of fungi. Actin and myosin are the proteins responsible for contraction in muscle cells; actin is also a microfilament in the cytoskeleton. Peptidoglycan is found in the cell walls of bacteria.

The plant cell wall is made of cellulose, which makes it rigid. The cell wall offers structural support and protection to the cell and it’s rigid nature maintains the regular shape of the cell. The cell wall is also permeable and allows small molecules, proteins, and nutrients to pass, including water and carbon dioxide.

Plant cells contain one very large vacuole that occupies a large percentage of the cell space. The central function of this vacuole is to maintain the turgor pressure of the cell through the continual transport of water and ions in and out of the cell, as needed. Vacuoles store and transport water, waste, and ions too.