Chapter 10 Multicellularity

What are the 2 main types of cells in the body?

(i) Germ cells or reproductive cells and (ii) Somatic cells or cells that makeup the rest of the body. The somatic cells are further divided into 8 major cell types based on the tissue they form. 1. Bone cells; 2. Cartilage cells; 3. Nerve cells; 4. Epithelial cells; 5. Muscle cells; 6. Secretory cells; 7. Adipose or fat cells; 8. Blood cells

What are the 6 basic cell processes to produce tissues and organs? Describe each step.

1. Cell division: Eukaryotic cells progress through a cell cycle that leads to cell division. 2. Cell growth: Following cell division, cells take up nutrients and usually expand in volume. Cell division and cell growth are the primary mechanisms for increasing the size of tissues, organs, and organisms. 3. Differentiation: turn into specialized types of cells. 4. Migration: During embryonic development in animals, cells migrate to their appropriate positions within the body.. Cell migration does not occur during plant development. 5. Apoptosis: Cell death, is necessary to produce certain morphological features of the body. For example, during development in mammals, the formation of individual fingers and toes requires the removal, by apoptosis, of the skin cells between them. 6. Cell connections: In animals, the ECM serves to organize cells within tissues and organs.In plants, the cell wall is largely responsible for the shapes of plant tissues. Different types of cell junctionsin both animal and plant cells enable cells to make physical contact and communicate with one another.

What are the 3 theories for evolution of multicellularity? Explain.

1.Symbiotic Theory - This states that first multicellular organisms arose from symbiosis of different species of single celled organisms, each with different functions. 2. Cellularization Theory - This theory states that a unicellular organisms that had many nuclei could have developed membrane boundaries/ partitions around each of its nuclei, thus giving rise to multicellularity. 3. Colonial Theory -This theory states that the symbiosis of many organisms of the same species led to a multicellular organism

What are the 5 different types of unicellular organisms?

Bacteria, Amoeba, protozia, viruses, diatoms

Eukaryotic

Cells with true nuclei. Membrane-enclosed nuclei & membrane-enclosed organelles

Plants are composed of what 3 tissues?

Dermal, Ground, and Vascular Tissues

Animals are composed of what 4 types of tissues?

Epithelial, Connective, Nervous, and Muscle Tissues

dermal tissue

Forms a covering on various parts of the plant. The epidermis refers to the newly made tissue on the surfaces of leaves, stems, and roots in a waxy cuticle to prevent water loss.Leaf epidermis often has hairs, or trichomes, that regulate the secretion of oils and offer protection. Epidermal cells called guard cells form pores in leaves, known as stomata, that permit gas exchange. The function of the root epidermis is the absorption of water and nutrients.

Define multicellular

Those living organisms that are made up of more than one cell.All the cells coordinate with each other in order to regulate the various functions of the body.

Differences between Uni- and multi-cellular organisms

Unicellular organisms Multicellular organisms a) Simple body construction (Single cell) a) Complex organization b) All functions controlled by single cell b) Contains specific organ (specific function) c) Prokaryotic in nature c) Eukaryotic in nature. d) Vegetative/Asexual reproduction d) Sexual type of reproduction e) Few introns in genome e) High introns in genome f) No cell differentiation f) Differentiation g) Engulf food g) Specific organ (Food production) h) Microscopic in nature h) Macroscopic in nature

Wha is the extracellular matrix (ECM)?

a network of material that forms a complex meshwork outside of animal cells. Plant cells are surrounded by cell walls. • Plant cells are surrounded by a cell wall. The primary cellwall is made first. It is composed largely of cellulose. The secondary cell wall is made after the primary cell.In the ECM of animals, proteins and polysaccharides are the major constituents. These materials are involved in strength, structural support, organization, and cell signaling.

Characteristics of Multicellular organisms

a) Multicellular Organisms reproduce by means of sexual reproduction. b) Multicellular Organisms have a complex anatomy because of the various cell organelles that control the functions of the organism. c) They are classified into germ cells that are the reproductive cells and somatic cells that help in body growth by cell division. d) Multicellular organisms have a very well-coordinated cell division process in order to prevent abnormal cell division and growth. e) The different cells in a multicellular organism may be the Nerve Cells, Skin cells, Cardiac cells, Epithelial cells, Connective Tissue Cells,Blood Cells,Bone Cells, Muscle Cells etc. f) Each of these cells have their own specific functions which helps in the overall functioning of the body.

Muscle tissue

can generate a force that facilitates movement. Muscle contraction is needed for bodily movements such as walking and running and also plays a role in the movement of materials throughout the body. For example, contraction of heart muscle propels blood through your body, and smooth muscle contractions move food through the digestive system

ground tissue

has a variety of functions, including photosynthesis, storage of carbohydrates, and support. Ground tissue can be subdivided into three types of simple tissues: parenchyma, collenchyma, and sclerenchyma.

vascular tissue

is a complex tissue composed of cells that are interconnected and form conducting vessels for water and nutrients. There are two types of vascular tissue called xylem and phloem. The xylem transports water and mineral ions from the root to the rest of the plant, while the phloem distributes the products of photosynthesis and a variety of other nutrients throughout the plant.

Epithelial tissue

is composed of cells that are joined together via tight junctions and form continuous sheets. Epithelial tissue covers or forms the lining of all internal and external body surfaces. For example, epithelial tissue lines organs such as the lungs and digestive tract. In addition, epithelial tissue forms skin, a protective surface that shields the body from the outside environment.

Autotrophs

organisms that are able to make energy-containing organic molecules from inorganic raw material by using basic energy sources such as sunlight. Example: Plants

Prokaryotes

organisms without a cell nucleus, or indeed any other membrane-bound organelles,

Connective tissue

provides support to the body and/or helps to connect different tissues to each other. Connective tissue is rich in extracellular matrix. In some cases, the tissue contains only a sparse population of cells that are embedded in the ECM. Examples of connective tissue include cartilage, tendons, bone, fat tissue, and the inner layers of the skin. Blood is also considered a form of connective tissue because it provides liquid connections to various regions of the body.

Nervous tissue

receives, generates, and conducts electrical signals throughout the body. In vertebrates, these electrical signals are integrated by nervous tissue in the brain and transmitted down the spinal cord to the rest of the body

Heterotrophs

take in organic molecules for nutrition. Typically store CH2O as glycogen. Lack cell walls. Unique intercellular junctions; possess tissues for impulse conduction & locomotion.