Science Unit Test Flashcards
Plant and animal cells
Cell theory:
- all living organisms are made up of one or more cells
- The cell is the simplest unit of life
- All cells come from pre-existing cells; they do not come from non-living matter
Type of cellls
- cells can be very simple (Prokaryotes) or complex (Eukaryotes)
- Prokaryotes are single-celled with no nucleus
- Eukaryotes are singled or multi cellular with complex internal structure
Cancer
- A group of diseases in which cells grow and divide out of control
Causes of cancer
- some types run in the family (Hereditary)
- some are caused by environmental factors
- Some have both causes
- Cancer is not infectious
- Cancer can be found in many types of organisms, both animals and plants
Hereditary
- Sometimes, DNA is not copied exactly during mitosis
- Random changes are called mutations
- These changes may result in the death of the cell
Why do cells divide
- growth
- Repair
- reproduce (asexually)
Sexual vs asexual reproduction
Asexual
- 1 parent
- clones of parents
- fast
Sexual
- 2 parents
- A mix of both parents
- Speed depends on the organism
Cell life cycle
Consists of three stages
1. interphase
2. mitosis
3. cytokinesis
The hierarchy of structure in animals
multi-cellular organisms are made up of different speciaized types of cells
- they can only function with other cells as a collective group
- they cannot survive on their own
Levels or organisms
- the cells within animals are organized into a hierarchy
- organ systems work together to make up an entire organism
Cell (Smallest) - tissue - organ - organ system - organism (largest)
Organ systems
- all organisms accomplish the same basic functions : obtain 02 and nutrients and eliminate waste
- Examples of some systems include:
musculoskeletal
respiratory system
nervous system
digestive system
organs
- each organ system is made up of highly specialized organs and other structures that work well together to perform an overall function
- most organs work within a single organ system (eg: stomach - digestive system)
- Some organs function in more than one system (eg: pancreas - digestive and endocrine systems)
Tissues
Animals have 4 large major types of tissues
- Epithelial tissue
- Connective tissue
- Muscle tissue
- Nerve tissue
The digestive system
is the organ system that takes food, digests it, breaks it down, and gets rid of the remaining waste
The mouth
Is the first step of the digestive system
- Breaks down food mechanically (with teeth and tongue)
The esophagus
Second part of the digestive system
- Connects the mouth to the stomach
Cytoplasm
- the fluid substance in the cell
- where chemical reactions occur
Cell membrance
- gives support to the cell
- controls the movement of materials in and out of the cell
Nucleus
- control center of the cell + directs all cell activities
- Chromosones contain DNA which is the generic information of the organism
Mitochondria
- Power plant of the cell
- It produces energy for cell functions
Endoplasmic reticulum
- network of branching tubes attacked to the nucleus
- passageway for materials moving to and from different parts of the cell
Ribosomes
- responsible for protein synthesis in cell
- made of RNA and protein
- Found in the cell, contains a nucleus
Golgi body
- collects and processes materials to be removed
- modifies protein that come from the ribosomes
- proteins shapes affect their function
Vacuoles
- role varies depending on cell
- can be used for storage of food, removing waste, maintaining fluid pressure, etc
- animal cells have many small vacuoles while plants have 1-2 very large ones
