SNC2D1: Biology Flashcards

Cell Theory

1. All living things are composed of cells
2. Cells are the smallest functioning unit of living organisms
3. All cells come from pre-existing cells

Reasons for cell division

Growth, Repair, Reproduction

Stages of the cell cycle

Interphase: G1, S, G2. Mitosis: Prophase, Metaphase, Anaphase, Telophase. Cytokinesis

What is interphase

The longest stage of the cell cycle, 90% of the cell's life is spend in this phase
Divided into three parts: G1 (First Gap Phase), S (Synthesis Phase), and G2 (Second Gap Phase)

What is first gap phase?

Cells grow in size and new organelles and proteins are created

What is the synthesis phase?

DNA (Chromatin) is replicated

What is the second gap phase?

Cells prepare for mitosis and cell division

What are chromosomes

Hereditary information contained in then nucleus, humans have 23 pairs. Composed of DNA and proteins. When the cell divides the daughter cells get the same chromosomes

What is Mitosis.

The process of dividing the cell into two identical daughter cells.

What are the four stages of Mitosis

Prophase, Metaphase, Anaphase, Telophase

What happens in prophase?

Chromatin condense to form sister chromatids
Centrioles move to the polls
Nuclear membrane breaks down

What happens during metaphase?

Spindle fibres attach to centromere (middle of sister chromatids)
Chromatids line up in the middle of the cell (metaphase plate)

What happens during anaphase?

The spindle fibres shorten, pulling the chromatins to the opposite poles as the centromere and the chromatids spli.

What happens during telophase?

The spindle fibres dissapear, chromatins untangle and form chromosomes
Nuclear membrane reappears around DNA groups

What is cytokinesis

The phase where the cell splits.

What happens during cytokinesis

The cell membrane pinches inwards, cytoplasm splits in half and the daughter cells return to interphase.

Plant Cell Division

Creates a cell plate, which forms in the middle of the cells and splits the cell.

Animal cell division

Creates a cleavage furrow, which pinches the middle and splits the cell.

Cell Death

Go Phase. Two types of death: Necrosis and Apoptosis.

What is Necrosis

The death of a cell caused by external factors (toxins, infections, trauma)

What is Apoptosis

Programmed Death, Cell Suicide/
Controlled death of old, damaged or unneeded cells

Cancer

Caused by genetic mutations which cause cells to change and start to undergo uncontrolled and abnormal mitosis.

Unique properties of Cancer cells

Do not stop reproducing
Act independently from other cells, don't form organs
Move around body, don't self-destruct

What is the Cell Theory

1. All cells come from other cells
2. All living things are made out of cells
3. The cell is the smallest unit of life

What is the Nucleus

Plants and Animals
- Communicates with the cell
- Contains the cell's DNA
- Produces ribosomes

Vacuoles

Plants and Animals*
- Stores nutrients, food and water
*Many small in animals, one big in plants

Vesicles

Plants and Animals
- Allows for movement of substances in the cellRou

Rough Endoplasmic Reticulum

Plants and Animals
- Ribosomes create rough texture on surface
- Transports proteins throughout the cell

Smooth Endoplasmic Reticulum

Plants and Animals
- Produces lipids and steroids
- Breaks down drugs and toxins
- Manages storage and release of calcium
- Carbs metabolism

Ribosomes

Plants and Animals
- Found floating or on RER.
- Builds proteins

Cytoskeleton

Plants and Animals
- Network of fibres
- Provides structure to the cell
- Allows for movement of organelles

Cell Wall

PLANTS
- On exterior the the cell membrane
- Strong, provides support for the plant cell
- Allows plants to grow at great heights

Cell Membrane

Plants and Animals
- Protects cell from surroundings
- Selectively permeable

Cytoplasm

Plants and Animals
- Gelatinous substance
- Supports organelles
- Contains nutrients

Mitochondria

Plants and Animals
- Site of cellular respiration
- Breaks down glucose, creates ATP

Lysosomes

ANIMALS
- Digestive enzyme used for digestion, fighting diseases and cell suicide

Golgi Apparatus

Plants and Animals
- Changes, stores and transports proteins from RER and lipids from SER

Chloroplasts

PLANTS
- Location of photosynthesis
- Contains chlorophyll, causes green colour in plants

Centrioles

ANIMALS
- Paired structures involved with cell division