Bio unit 1

Define Biology

the study of living things

Define Cell

The smallest structural unit of an organism

Define Homeostasis

The ability to maintain a constant internal environment

Define Adapt/evolve

the ability of groups of living things to change over time due to changes in genetic information

What does Response to stimuli mean?

A reaction to a change in the environment

Define Reproduction

All living things make similar living things

What is the purpose of DNA/genetics?

store info that is needed to live, grow, and reproduce in a genetic code

Define metabolism

the chemical processes that occur within a living organism in order to maintain life.

Define Stimuli

A thing or event that evokes a specific functional reaction in an organ or tissue

Define excretion

the process of eliminating or expelling waste matter

What are the three rules of cell theory?

1. All living things are made up of one or more cells

2. Cells are the basic unit of life

3. All cells come from pre-existing cells

What were the atmospheric conditions of early earth (1) and how did they affect the temperature (2)?

1. The atmosphere lacked free oxygen and ozone, with an abundance of Carbon Dioxide and Methane

2. Without ozone there was more UV light and both CO2 and CH4 are greenhouse gases. Both of these factors contributed to the increased temperature on early earth.

What was the Miller-Urey experiment and what did it prove?

The Miller Urey experiment was created to simulate the conditions of prebiotic earth to discover what kinds of molecules would have survived at the time. It proved that organic compounds, such as amino acids. could be formed spontaneously in the conditions of early earth.

What are the criticisms of the Miller Urey experiment?

They assumed that the conditions they simulated were similar enough to the conditions on early earth that their data is correct. Because we have no way of really knowing how close the experiment was to the original conditions, the accuracy of the study is questionable.

Define unicellular

consisting of a single cell

Define multicellular

made of many cells

What are 3 conditions that are maintained by homeostasis?

1. Body temperature

2. Fluid balance

3. Body pH

Define phototropism

a response in which parts of a plant grow towards or away from the direction from which light is coming

Define geotropism/gravitropism

a response in which parts of a plant grow towards or away from gravity

What are the characteristics/processes of life that viruses DO have?

The ability to reproduce

the ability to mutate

What are the 8 processes of life that IB wants you to know?

1. Metabolism

2. Response to stimuli

3. Homeostasis

4. Movement

5. Growth

6. Reproduction

7. Excretion

8. Nutrition

What are the characteristics/processes of life that viruses DON'T have?

Homeostasis

They can't grow

They can't make their own energy

They are not made out of cells

What are the 3 rules of cell theory?

1. All living things are mad of one or more cells

2. Cells are the basic unit of life

3. Cells come from pre-existing cells

What were the conditions on early earth? (4)

- Atmosphere lacked free oxygen and ozone

- A lot of carbon dioxide and methane

- More UV light due to lack of ozone

- Higher temperature because of greenhouse gasses

What did the Miller Urey experiment attempt to create?

The conditions of pre-biotic earth

Define prebiotic

existing before the emergence of lie

What was the goal of the Miller-Urey experiment?

To find what kinds of molecules could form in early earth conditions

What gasses and conditions were used in the miller Urey experiment? (5)

1. H(2)O

2. CH(4)

3. NH(3)

4. H(2)

5. Heat and electricity

What was created in the Miller Urey experiment?

Amino Acids (used to form proteins, vital to life)

What does organic mean in the context of prebiotic earth?

A molecule containing carbon

What is a criticism of the Miller-Urey experiment?

They are assuming that the conditions they created are accurate to the conditions that existed

Define protocell

they are the cells that came before the first living cell, helping to form the cells that we have today

How and where were protocells thought to form?

Formed spontaneously in an aqueous environment

What does "spontaneous formation of vesicles" mean?

When in an aqueous environment, fatty acids will spontaneously self-assemble to form spherical bilayers

What is the purpose of the membrane?

To separate the internal and external environments of the cells

What is the connection between the cell membrane and the eight processes of life?

Homeostasis; the ability to maintain a balanced internal environment despite outward environmental factors

Why is RNA thought to be the first genetic material?

Because of its catalytic properties

What are two pieces of evidence for LUCA?

1. Universal genetic code: DNA records/is stored and interpreted in the same way

2. Genes are the same in all organisms

When was LUCA likely to have existed?

2.5 - 3.5 billion years ago

What are some characteristics of LUCA? (3)

- Unicellular

- Autotrophic: can make and use its own energy

- LUCA was the best at existing but it is possible that other beings existed at the time that did not prevail

Where is it thought that LUCA existed and why?

There is fossil evidence that LUCA evolved around hydro-thermic vents in the ocean because they are very mineral rich

What are the differences between eukaryotic and prokaryotic ribosomes?

Prokaryotic ribosomes are 70s and Eukaryotic ribosomes are 80s

What are the four types of eukaryotic organisms?

1. Plants

2. Animals

3. Fungi

4. Protists

What are the organelles in both animal and plant cells and what does each one do? (5)

1. Mitochondria: where energy is released

2. Ribosomes: make proteins

3. Cytoplasm: enzyme-controlled reactions happen here

4. Nucleus: controls cell and stores DNA

5. Cell membrane: controls what goes in and out of a cell and helps keep homeostasis

What are the organelles only found in plant cells and what does each one do? (3)

1. Cell wall: Strengthens and supports cell

2. Chloroplasts: stores chlorophyll inside for photosynthesis

3. Central vacuole: stores water

Define Cilia

slender protuberances that project from a larger cell body

Define flagella

lash-like appendages that protrude from a cell body

What are the differences between cilia and flagella? (5)

1. Number: thousands of cilia: 1-8 flagella

2. Length: Cilia shorter: flagella longer

3. Beating pattern: Cilia pattern is complicated with a wide range of motion: flagella pattern follows a circular/propeller pattern

4. Where: cilia only found in eukaryotic cells: flagella found in both eukaryotic cells and prokaryotic cells

5: number of types: 2 types of cilia: 3 types of flagella

What are the two types of cilia?

1. non-motile

2. motile

What are the 3 types of flagella?

1. bacterial

2. archaeal

3. eukaryotic

Which eukaryotic cell has a cell wall?

Plant (cellulose)

Fungus (chitin)

Which eukaryotic cell has vacuoles?

Animal (small and temporary)

Plant (large and permanent)

Fungus (large and permanent)

Which eukaryotic cell has chloroplasts?

Plant