The Living Environmentthe year so far ...

What does it mean to be alive?

Characteristics of Life

MRLSTRNGR

MetabolismRegulationLocomotionSynthesisTransportRespirationNutritionGrowthReproduction

Characteristics of Life

Cells are the building blocks of life

Every organelle has a job to do

And they each help to maintain homeostasis

Ecology

Ecology is all about relationships

Biotic Factors depend upon Abiotic Factors

Everything eats everything else

Energy Flows Through the System

Things move from the simple to the complex

Nutrients Come and Go

and Biodiversity is King

Genetics

4 Parts of Genetics

Inheritance

Rules of Inheritance

There are different versions of each trait.

Traits are inherited from your parents.

You inherit one version of each trait from each of your parents.

You need both versions of the trait to show (express) the trait* (*except not always).

Not all versions of a trait are equal.

Inheritance Concepts

Dominant - only one version of the gene needs to be present for the trait to be expressed.

Recessive - both versions of the gene need to be present for the trait to be expressed.

Incomplete dominance - a blending of the two versions of the trait.

Co-dominance - both versions of the traits are expressed.

Genes and Chromosomes

Chromosomes are made of DNA.

Humans have 23 pairs of chromosomes.

Genes are sections of a particular chromosome.

Each gene is a recipe for a specific protein.

The recipe is a string of nitrogenous bases.

Any change to the recipe is called a mutation.

The structure of DNA

DNA is a double helix or twisted ladder.

Backbone - sugar (deoxyribose) and phosphate

Rungs - nitrogenous basis (Adenine, Thymine, Guanine, Cytosine)

RNA Structure

RNA is a single-stranded molecule.

Backbone - sugar (ribose) and phosphate

Rungs - nitrogenous basis (Adenine, Uracil, Guanine, Cytosine)

DNA Replication

The DNA molecule unzips (thanks to enzymes).

Each strand builds a complimentary strand.

One becomes two.

Protein Synthesis, part 1

A section of the DNA is unzipped (again thanks to enzyme action).

A strand of mRNA makes a copy of the recipe for a particular protein.

The mRNA leaves the nucleus and attaches to a ribosome.

Protein Synthesis, part 2

The mRNA is attached to the ribosome.

Strands of tRNA (with only 3 bases) pair up with the strand of mRNA.

tRNA carries amino acids, which bond together to form proteins.

When complete, the mRNA and tRNA move on to make more proteins, the protein goes to do whatever it is supposed to do.

Mitosis

Type of cell division used for growth and repair.

One cell becomes two cells.

The parent and offspring are genetically identical.

Mitosis happens in phases (IPMAT).

Mitosis

Meiosis

Type of cell division used to make sperm or egg cells (gametogenesis).

One cell becomes four cells.

The parent and offspring are genetically different, and the offspring cells have half the number of chromosomes as the parent (haploid).

Meiosis happens in phases (IPMAT X 2).

Meiosis

Evolution

Species Change Over Time

Evidence for Evolution

Fossil Record

Homologous Structures

Analogous Structures

Vestigial Structures

Embryonic Development

Fossil Record

Homologous and Analogous Structures

Vestigial Structures & Embryonic Development

Why it works

How it works

Reproduction

Asexual Reproduction

Offspring and parents are genetically identical.

Allows for the least amount of genetic variation.

There are many types.

Sexual Reproduction

Offspring and parents are genetically different.

Allows for the most amount of genetic variation.

Fertilization and embryonic development can occur inside or outside the body.

Embryonic Development

The fertilized egg (zygote) develops into a mature organism.

Typically has many stages.

Involves cleavage, patterning, differentiation, growth.

Menstrual Cycle

Prepares an egg for fertilization.

Prepares the woman’s body for an embryo.

Human Body Systems

What to know

The parts

What the parts do

How does this system help maintain homeostasis?

How does this system work with others to maintain homeostasis?

If the functions are interrupted, that’s a disease

The body systems work together to maintain

homeostasis

Other important stuff

Diffusion

Stuff moves from where there is more to where there is less ... until a balance is reached.

Surface Area to Volume Ratio

A comparison between the amount of space on the surfaces of an object and the amount of space that object occupies

On the outside(make it as small as

possible)

On the inside (make it as big as possible)

EnzymesEnzymes are proteins that make chemical reactions go faster.

Enzymes are specific to one chemical reaction.

Enzymes are not used up by the reactions in which they participate.

Enzymes fit with the molecules they act on like a lock and key.

Anything that changes the shape of an enzyme (like heat) changes what it does.

Enzymes

Feedback Mechanisms

This is an important way that regulation happens in our bodies.

Feedback mechanisms are like thermostats -- they manage an area of homeostasis around a certain set point.

In order to work, there have to be receptors, set points, and controls.

Feedback Mechanisms

Hormones

Hormones are chemical messengers that tell other parts of the body what to do and when.

9 endocrine glands make over 100 hormones.

Cells have receptors for hormones. If they have receptors for a specific hormone, that hormone can effect the cell. Otherwise, it cannot.

Hormones

Some themesThe more biodiversity, the healthier the ecosystem.

The more genetic variation, the more ability organisms have to adapt and survive.

Every part of a system is connected to every other part (cells/organelles, bodies/body systems, biotic/abiotic, genes/chromosomes).

Humans can have positive or negative impacts on the rest of the world.

The End(for now....)