Cells and Evolution

Unit 1 - Life Sciences 11

Organisms

Are any living things like an individual plant, animal, or single-celled life form

What are the four things all organisms need?

Water, Nutrients, Space, and Air (oxygen or carbon dioxide)

Why is water essential for organisms

It helps the organism to fulfill cellular activity

ex) DNA replication, cell division, protein synthesis, breaking down food, and transporting nutrients and waste

Why is Nutrients essential for organisms

It provides organisms what they need to grow

What is an Autotroph and what is a Heterotroph?

An autotroph is a producer, an organism that makes the food they need

ex) plants and some bacteria

A heterotroph is a consumer, an organism that finds its nutrients from external sources

ex) carnivores, herbivores, omnivores

Why do plants still need nutrients even if they are autotrophs?

1. They make food for energy, not for growth

2. Nutrients like phosphore or potassium provide the building blocks for growth

3. The external nutrients help with the roots, flowers, and healthy cells of a plant

Why is a space to live important for organisms

It is used to have easy access to water, food, and shelter

Why do organisms often compete for space?

Organisms compete for space as it limits available food, water, and shelter. If a space is already taken, or filled to the brim, organisms fight each other to keep it. Since there won’t be enough food, water, or shelter for everyone

Why is air needed for organisms to live

Air (CO2 or O2) s needed for organisms to live as it’s used for photosynthesis and cellular respiration

Photosynthesis

A chemical process in which green plants use sunlight to produce energy, that happens in the chloroplasts

Cellular respiration

A process which stored energy is broken down to release energy, that happens in the mitochondria

When does photosynthesis and cellular respiration occur

Photosynthesis occurs when there is sunlight, so during daylight hours

While cellular respiration happens all the time

What is the input and output of photosynthesis

carbon dioxide, water, and sunlight, into glucose and oxygen

What is the input and output of cellular respiration

Glucose and oxygen into carbon dioxide and water

What cell does photosynthesis and cellular respiration occur in

Photosynthesis is unique to plant cells

Cellular respiration is in both plant and animal cells

What is the energy result of both these reactions

Photosynthesis ends with stored energy

Cellular respiration ends with released energy

What is their equations

Photosynthesis 6CO2+ 6H20 + sunlight → 6O2 + C6H12O6

Cellular Respiration 6O2 + C6H12O6 → 6H2O + 6CO + ATP (adenosine triphosphate)

What are the 8 characteristics of living organisms

Cells (are made of cells)

Homeostasis (maintain internal balance)

Energy (obtain and use energy)

Reproduce

Traits (pass traits off to offspring)

Grow

Respond (to their environment)

Change (evolve. over time as a species)

All organisms are made of ____

cells

Two types of cellular organisms

Unicellular

Multicellular

What’s the difference between unicellular and multicellular organisms

In a unicellular organism, there is no cell specialization, it can be a prokaryote or a eukaryote, it consists of only one cell, and that one cell carries out all the function required to maintain the life of the organism.

In a multicellular organisms there is more than one cell, these. cells develop differently thanks to cell differentiation, which leads to cell specialization

Homeostasis

Is the ability to maintain internal balance in response to environmental changes

ex) IN humans when it’s hot, we sweat to cool down

when its cold, we shiver to warm up

We MUST need to be in homeostasis for our bodies to function properly

All organisms use _____

energy

What does energy do for an organism

it powers daily functions, and repairs/replaces damaged cells

ATP(adenosine triphosphate) is a cell’s energy currency

All organisms can _____

reproduce (making offspring or descendants through asxual or sxual reproduction)

Sexual reproduction

When two parents with different genes make offspring with different genes

Asexual reproduction

When one parent produces offspring that is identical to them (clone)

All organisms pass _________

off traits to their offspring

How are the traits passed off

Through genes found in DNA (Deoxyribonucleic acid)

During both asexual and sexual reproduction

All organisms ___

Grow

How can organisms grow

By cells increasing in number or SIZE

Bacteria grows by increasing it’s size, then dividing

All organisms ____ to changes in their environment

respond

What is a stimulus

Any activity that bring out a response

Internal Stimulus v.s. External stimulus

An internal stimulus is something that happens inside you, that you cannot control

Ex) hunger(stimulus) → you eat (response)

Thirst (stimulus) → you drink water (response)

An external stimulus is something that happens outside of you, it can be controlled or limited

ex) light(stimulus), keeps you awake (response)

sound(stimulus), → you’re more aware of your surroundings (response)

What is a response

It is an action (something you do)

As a species, all organisms _____ over time

change

Natural selection

the process where traits best suited for the environment will survive to be passed on

Can individuals evolve?

No, only the population as a whole can evolve

Organization of an organism

Atom→Molecule→Organelle→Cell→Tissue→Organ→Organ System→Organism

Cells

specialized cells to carry out functions ex) muscle cells and nerve cells

Tissues

A group of cells that are similar in shape and function ex) Skin/epithelial tissue

Organ

Multiple tissues that are organized into larger structures with one main function ex) hear, lungs, liver

Organ system

Group of organs that have related functions ex) circulatory

Cell Specialization

How cells are specialized in their functions

What is a cell

The smallest unit of life that has all the characteristics of living things

What is structure a synonym to for cells

appearance

Two types of cells

Prokaryote and Eukaryote

Prokaryote

• Unicellular organisms (simple)

• They are all bacteria

• No membrane bound organelles

If all prokaryotes are bacteria, then is all unicellular organisms bacteria

no

Eukaryotes

• Complex multicellular OR unicellular organisms

• Contains membrane-bound organelles including the nucleus

• Most living things

Three examples of cell specialization

Neurons( nerve cells)

Red blood Cells

Sperm cells

Neurons

Sends info from one part of the body to another

Very long and thing (this form helps with the transportation of info)

Red blood cells

Carry oxygen and nutrients through the body

Shaped like a flattened disc so that they can easily flow through blood vessels AND carry oxygen and nutrients

Sickle Cell Anemia Disease

The red blood cells are shaped differently into sickle (kinda like a crescent moon)

Because of the change in structure, the ability to carry out oxygen (function) is hindered

Sperm Cells

Fertilizes egg cells

Its structure is made for quick swimming due to its strong tail. The distinct head is use to easily enter the egg cell

Cell differentiation

Is a result of gene expression, a process in which a gene is switched on or off, resulting in different proteins being made

Most cells in your body have the same DNA, but

They only use the DNA(deoxyribonucleic acid) they need, the rest remains turned off

Give an example of cell differentiation

Skin cells only use codes for melanin (skin pigment that protects you from the uv), where heart cells do not need melanin, so that code is shut off

How is all of this knowledge being used

through Stem cells

stem cells

can become almost any cell in your body, since they have not undergone cell differentiation

What can stem cells be used for

They can be used to repair damaged organs, and cure some diseases. Currently, scientists are trying to figure out how to regrow limbs (like a finger or an arm) using stem cells

What is the ultimate stem cell and why

The embryonic stem cell is the best, since it truly can turn into any cell. Adult stem cells are limited, and can only turn into fewer cells, plus are rarer among grown adults than embryos.