Cell Theory Flashcards
Organisation; cells, tissues, organs, systems
Cells and Tissues
Tissue – a collection of specialised cells grouped together. Examples include:
Nerve tissue (made up of nerve cells called neurons)
Muscle tissue (made up of muscle cells called fibres)
Reproductive tissue
Connective tissue (which includes skin, red and white blood cells)
Tissues and Organs
A collection of tissues grouped together to perform a specific function is called an organ. Examples include:
The heart is made up of cardiac muscle (allows for contraction and expansion), nerve tissue (allows for control of muscle) and blood (connective tissue).
Organ Systems
Different organs grouped together to carry out a function are called an organ system.
The digestive system is made up of organs that are important for digesting food and liquids. These include the mouth, pharynx (throat), esophagus, stomach, small intestine, large intestine, rectum, and anus.
Plant Cells and Tissues - Epidermis
Epidermis tissue – cells with a root hair that are found near the root tips. Increases surface area to volume ratio to efficiently take in water.
Plant Cells and Tissues - Xylem Tissue
Xylem tissue – found inside the stem, allows for transport through tube-like cells call xylem vessels. The chain of xylem vessels in the stem allow it to transport water and dissolved minerals from the roots to other parts of the plant.
There is another set of vessels called phloem – these are responsible for transporting products of photosynthesis (sugar)
Plant Cells and Tissue - Mesophyll tissue and reproductive tissue
Mesophyll tissue – makes up leaves, consists of palisade and spongy mesophyll cells.
Reproductive tissue – cells in the ovary produce ova
Plant organs made up of tissues
- Roots – made up of epidermis tissue, xylem, phloem
- Stem – made up of epidermis tissue, xylem, phloem, and two other tissues called cortex and pith.
- Leaves
Structure and function of leaves
The function of the leaf is to carry out photosynthesis to produce glucose. Leaves have an abundance of mesophyll cells, which are packed with chloroplasts (the organelle responsible for photosynthesis)
Leaves have a ‘spongy’ section – this allows for gases (O2 and CO2) to be exchanged with the outside air.
The vein allows for transport of H2O into the leaf, and glucose our of the leaf.
Plant Organ systems
- Root System:
- Two types of plants – dicotyledons and monocotyledons
- Dicot root system has a main root (called a taproot) from which other roots branch off (e.g. roses)
- Monocot root system lack a taproot, consist of many shallow roots instead (e.g. grasses)
- Shoot System – consist of the stem and leaves. The role of the shoot system is to transport materials.
Human organ systems
respiratory system, digestive and excretory system, circulatory system, urinary system, skeletal system, endocrine system, lymphatic system, nervous system, and reproductive systems.
