BiologyTAKS Review

TAKS covers a lot of Biology…

for more help with Biology after today,

check out AM/PM and lunch tutoring!

Let’s start with Ecology…

Food Chain

What terms would you use to describe

each step in the food chain?

A food chain shows the flow of energy

through the organisms in a

community

Food Chain

Producer

Primary Consumer

Secondary Consumer

Tertiary Consumer

Quaternary

Consumer

Food ChainThe arrows show the direction of

ENERGY FLOW!

For example, energy flows from the plant to the grasshopper when the grasshopper eats the plant.

It does not matter which way food chain is placed on

paper…arrows always go in direction of energy flow!

Energy still goes from the plant to the grasshopper, then mouse, then snake,

then eagle…follow the arrows!

Food Chain

The producers contain the MOST energy

contains the LEAST energy.

LEAST Energy

MOST Energy

Only 10% of the energy at one level is passed on to the next energy level.

90% of energy is lost as heat

Food Webs

Food Webs are lots of food chains linked together…use the same terms to describe organisms!

Food Webs

Which organisms are the producers?

Food Webs

Which organisms are the primary consumers?

Food Webs

Which organisms are

herbivores?

Food Webs

Which organisms are

carnivores?

Food Webs

Which organism is an

omnivore?

Food Webs

What’s missing?!?Decomposers!

(bacteria or fungi)

Let’s practice…Try questions 1-13 on

your review packet

Now let’s talk about relationships

between organisms…

• This type of relationship benefits both organisms involved.

• Example: A bee and a flower.

Mutualism

It’s good for the bee because the bee needs the pollen to make honey. It’s good for the flower because the bee will pollinate the flower, and a flower needs to be pollinated for reproduction.

Mutualism

• This type of relationship benefits one

of the organisms and harms the other organism involved in the relationship.

• Example: A flea on a cat. A leech on an animalIt is good for the flea because the flea gets its nourishment from the cat. It is bad for the cat because the flea bites the cat and opens the skin for possible infection, and the cat also loses blood.

Parasitism

It is good for the It is good for the barnacle because it barnacle because it needs somewhere to needs somewhere to live, but it doesn’t harm live, but it doesn’t harm the shell.the shell.

Commensalism

• In this type of relationship, one organism benefits while the other organism is neither harmed nor benefited.

• Example: Barnacle on a shell.

Predation

• In this type of relationship, one organism captures another organism for food.

• Example: A lion eats a zebra

Let’s practice…Try questions 14-20 on

your review packet

Now let’s talk about

CELLS…

All cells have…1. Genetic Material…DNA in chromosomes

2. Cell membrane

3. Cytoplasm – fluid inside the cell

4. Ribosomes – organelles that make proteins

There are two main types of cells….

1. Prokaryotic Cells- ONLY Bacteria- do NOT have a nucleus or any other

organelles surrounded by membranes

2. Eukaryotic Cells- found in animals, plants, fungi, and protists- DO have a nucleus and other organelles surrounded by membranes

There are two main types of cells….

Prokaryotic cells are much smaller than eukaryotic cells.

Viruses are even smaller and NOT made up of cells. They are considered to be nonliving. They reproduce inside a host cell.

Eukaryotic Cell

Prokaryotic Cell

NOT living

(no nucleus)

(has nucleus)

There are two types of bacteria….

1. Kingdom Eubacteria- no nucleus, typical bacteria, have cell wall

made up of chemical called peptidoglycan- Ex. Streptococcus pneumoniae is a bacterium that

causes pneumonia…can be treated with antibiotics

2. Kingdom Archaebacteria- no nucleus, live in extreme

environments, cell walls lack peptidoglycan- Ex. bacteria that live in polar ice caps or

undersea volcano vents

Four Eukaryotic Kingdoms….

1. Kingdom Animalia- eukaryotic, multicellular- no cell wall, no chloroplasts, no central vacuole

2. Kingdom Plantae- eukaryotic, multicellular- cells do have cell wall made of cellulose surrounding cell membrane- have chloroplast for photosynthesis- also have central vacuole for water storage

Heterotrophs!

Autotrophs!

Four Eukaryotic Kingdoms….

3. Kingdom Fungi- eukaryotic, multicellular- no chloroplasts, no central vacuole- cell wall made of chitin

4. Kingdom Protista- eukaryotic and mostly UNICELLULAR- some have cell walls, some do photosynthesis- move with cilia, flagella, pseudopodia- very DIVERSE kingdom!

Remember that fungi are one of our types of

decomposers!

What type of cell is this?

How do you know?

No cell wallNo chloroplast

No central vacuole

Animal Cell

What type of cell is this?

How do you know?

Prokaryotic (Bacterial) Cell

No nucleusRibosomes, but no

other organelles

DNA NOT in a nucleus!

What type of cell is this?

How do you know?

Protist Cell

EukaryoticUnicellular organism

Use cilia to move

What type of cell is this?

How do you know?

Protist Cell

EukaryoticUnicellular organism

Use psuedopodia to move

What type of cell is this?

How do you know?

Plant Cell

Cell WallChloroplast

Central vacuole

What type of cell is this?

How do you know?

Protist Cell

EukaryoticUnicellular organismUse flagella to move

Let’s practice…Try questions 21-30 on

your review packet

What do all of those cell organelles do?

Cell Membrane

Controls what goes in and out of cell

Selectively permeable to maintain homeostasis

Nucleus

Contains DNA, control center of

the cell

Mitochondria

Powerhouse of the cell – makes ATP in cellular

respiration

TIME OUT!Aerobic Cellular Respiration Reminder:

Cells convert the stored chemical energy in glucose (a sugar) to chemical energy

stored in ATP using oxygen…produces carbon dioxide and water.

This occurs in the mitochondria!

C6H12O6 + O2 CO2 + H20

Ribosomes

Ribosomes make proteins…they are in ALL cells

tiny dots

Endoplasmic Reticulum

Transportation system to move proteins in cell

Golgi Apparatus

“Post Office” of the cell – modifies and packages proteins to be secreted

from the cell

Lysosomes

contain enzymes that recycle cellular material

Cell Wall

Provides support for plant cell

Chloroplast

Site for photosynthesis

Makes sugar using sunlight energy

TIME OUT!Photosynthesis Reminder:

Cells convert solar energy to glucose (a sugar) using water and carbon dioxide…produces oxygen.This occurs in the chloroplasts!

It’s the opposite equation of respiration!

C6H12O6 + O2 CO2 + H20 CO2 + H20 C6H12O6 + O2

Central Vacuole

Stores water

Let’s practice…Try questions 31-39 on

your review packet

Now it’s time for DNA and protein synthesis…

Structure of DNA(Deoxyribonucleic Acid)

Twisted ladder shape… a double helix

Made up of molecules called nucleotides

Inherited from gametes of parents

Each nucleotide is made up of a sugar

(deoxyribose), a phosphate group,

and a nitrogen base.

Nucleotide

There are 4 nucleotides:

Adenine (A)

Cytosine (C)

Guanine (G)

Thymine (T)

Adenine pairs with Thymine and Cytosine pairs with Guanine

T A

G C

C G

TA

Mistakes in DNA

Mistakes in replicating DNA are called mutations.

Only mutations that are made in gametes (sex cells…sperm and eggs) are

passed on to offspring.

When a cell wants to make a protein…

Step 1 – TRANSCRIPTION:

Cells makes a strand of messenger RNA from the DNA template

If nitrogen base in DNA is CGATGTACGGTAA

what is sequence of nitrogen bases in mRNA?

When a cell wants to make a protein…

Step 1 – TRANSCRIPTION:

Cells makes a strand of messenger RNA from the DNA template

If nitrogen base in DNA is CGATGTACGGTAA

what is sequence of nitrogen bases in mRNA?

Remember!RNA contains the nitrogen base

URACIL (U) instead of THYMINE (T)

So when the DNA base is ADENINE, the mRNA that pairs

with that base will be URACIL

When a cell wants to make a protein…

Step 1 – TRANSCRIPTION:

Cells makes a strand of messenger RNA from the DNA template

If nitrogen base in DNA is CGATGTACGGTAA

what is sequence of nitrogen bases in mRNA?

mRNA = GCUACAUGCCAUU

When a cell wants to make a protein…

Step 2 – TRANSLATION:

Ribosomes read mRNA and make a protein by linking together amino acids

Transfer RNA (tRNA) molecules bring the correct amino acid to the ribosome

based on the mRNA code

Protein

Ribosome

tRNA

Universal Codon Chart

Let’s make sure you know how to read this chart, so that you can

translate mRNA chains into amino acid chains!

Universal Codon Chart

Try to translate this sequence of mRNA

codons…

AUG CCG GAG UUA

= methionineAUG?

CCG? = proline

GAG? = glutamate

UUA? = leucine

So the mRNA strand of AUG CCG GAG UUA codes for

the amino acid sequence…methionine – proline – glutamate - leucine

Let’s practice…Try questions 40-50 on

your review packet

Now it’s time for Punnett squares…

Punnett Squares

Gametes are cells that fuse with other cells during fertilization.

Punnett Square Terminology

• Homozygous • Dominant

• Recessive

• Heterozygous

• Phenotype

• Genotype

Genotype vs. PhenotypeDominant vs. Recessive

In pea plants, spherical seeds (S) are dominant to dented seeds (s). In a genetic cross of two plants that are heterozygous for the seed shape trait, what fraction of the offspring should have spherical seeds?

Example

Gametes from Parents

S s

S

s

SS Ss

sS ss

Question: What is the chance of having a homozygous recessive plant?

Question: What is the chance of having spherical seeds?

Lets finish up with human systems…

Human Systems

Human Systems

Skeletal System:Role – provide support and protection for the body.Major Organs - Bones, cartilage, tendons and ligaments

Human Systems

Muscular System:Role – provide movement for the body.Major Organs - skeletal and smooth muscles.

Human Systems

Circulatory System:Role – transport nutrients, gases (such as oxygen and CO2), hormones and wastes through the body. 

Major Organs - heart, blood vessels, and blood.

Human Systems

Nervous System:Role – to relay electrical signals through the body

Major Organs - Brain, spinal cord and peripheral nerves.

Human Systems

Respiratory System:Role – to provide gas exchange between the blood and the environment. 

Major Organs - Nose, trachea and lungs

Human Systems

Digestive System:Role – to breakdown and absorb nutrients

Major Organs - Mouth, esophagus, stomach, small and large intestines.

Human Systems

Excretory System:Role – to filter out cellular wastes, toxins and excess water or nutrients from the circulatory system. 

Major Organs - Kidneys, ureters, bladder and urethra

Human Systems

Endocrine System:Role – to relay chemical messages through the body

Major Organs - hypothalamus, pituitary, thyroid, pancreas and adrenal glands.

Human Systems

Reproductive System:Role – to manufacture cells that allow reproduction

Major Organs - ovaries, uterus, testes, seminal vesicles and sperm. 

Human Systems

Lymphatic/Immune System:Role – to destroy and remove invading microbes and viruses from the body

Major Organs - Lymph, lymph nodes and vessels, white blood cells, T- and B- cells.

Human Systems

Integumentary System:Role – to protect the body and act as a receptor.

Major Organs - skin

Let’s practice…Try questions 51-70 on

your review packet

Remember that tutoring is

available if you would like more

help preparing for the TAKS!

THE END