Biology Term 2

#1

Define Unicellular Organisms

Independent organisms that are their own identity and can individually carry out all necessary life functions to survive

Define Multicellular Organisms

Organisms made up of two or more cells that are specialized cells to support different life functions. Often larger SA:V

Define Colonial Organisms

Organisms that exist as a group of genetically identical individuals, with cells that can survive individually.

What is Paramecium

Unicellular Protozoan

What are the characteristics of Paramecium

Cilia: Enables movement and sensitivity to environment

Microvilli: Absorbs Water + Nutrients

Obtains nutrients through diffusion to grow

Divides Asexually after reaching a certain size

What are Chlamydomonas

Unicellular Algae

What are the characteristics of Chlamydomonas

2 Flagella Enables movement

Contractile vacuoles collect and eject water

Eyespot detects light to enable photosynthesis

Disadvantages of Unicellular Organisms

Remain Microscopic while evolving

Less efficient without specialized cells

Limited environment availability due to evolution

Where do different Cell types arise

Embryo

Where do specialized cells arise

Stem cells found in the embryo

Recall Colonial Flaget Hypothesis

-Evolution process of how Multicellular organisms came to be

-Unicellular Flaget Protist forms spherical colony

-Different cells become specialized to carry out different functions to maintain life

-Eventually, they’d become too dependent on one another and not survive individually

What are Choanoflagellate

Unicellular Flagellates that can aggregate to become colonial

What is Volvox

A colonial Algae

Characteristics of Volvox

Colonial

50,000 different cells

Flagella enables movement

Lacks organs + tissues

Can perform photosynthesis

Somatic body cells can’t reproduce

Gonidia Reproduce but can’t move

Advantages of Cell specialization

Allows cells to grow large

More efficiency in sustaining life

More environment availability

How do Organ systems come to be

Specialized cells → tissues → Organs → Organ systems

What are the vascular bundles made of

Cambium, xylem, phloem

What does the xylem do

Transport water and minerals from soil in roots unidirectionally upwards to leaves to fuel photosynthesis

What does the phloem do

Transport resultant sugar bidirectionally around plant to feed them

Recall the four animal tissues

Epithelial tissue, connective tissue, nervous tissue, muscle tissue

Describe the Epithelial tissue

-Covers body tissues to protect organisms

-No red blood vessel

-Relies on underlying connective tissue for nutrients

-Closeness of cells create a barrier protecting against infection

Describe the connective tissue

   -Made of protein fibres, collagen for strength, and elastin for flexibility

             -Binds different parts of the tissue

             -Cells scattered through extracellular matrix

Describe nervous tissue

 -Specialized for communication between all parts of the body with neurons in Nervous system

Describe Muscle tissues

  -Fibres specialised for contraction

             -Actin and myosin proteins to lengthen and shorten cells