Biology- Midterm Review

by Ruth hailu

What are the 8 characteristics of life? (RACEHOGS)

1) Reproduces and Produces Offspring

2) Adaptations Evolve Over Time

3) Made up of one or more Cells

4) Requires Energy

5) Maintains Homeostasis

6) Displays Organization

7) Grows and Develops

8) Responds to Stimuli

• adjusts to changes in the environment

Observation

• using one or more of your 5 senses to gather information

• includes qualitative & quantitative

Quantitative observations

involves numbers, or an amount.

Qualitative observations

involves descriptions that cannot be expressed with numbers (colors, texture, etc.)

Inference

when you explain the things you observe

(ex. you observe 2 boys playing soccer tg and you make an inference that they are brothers)

Bar graph

used to compare amounts

Line graph

used to show the changes over time

Pie chart

used to show parts of a whole

Scatterplot

used to show correlation between variables to determine best-fit line

Hypothesis

• Definition: A testable prediction about what will happen in an experiment.

• How it contributes: It gives the experiment a clear question or idea to test.

Variables

• Definition: Factors that can change in an experiment.

• How it contributes: They help show what is being tested and what is being measured.

  • (Independent = what you change; Dependent = what you measure)

Control / Constants

• Definition: The control is the group not tested; constants are things kept the same.

• How it contributes: They make sure the results are fair and only the variable being tested causes the change.

Conclusion

• Definition: A statement explaining what the results show.

• How it contributes: It tells whether the hypothesis was supported or not based on data.

Validity

• Definition: How accurate and reliable the experiment is.

• How it contributes: It shows whether the experiment was done correctly and if the results can be trusted.

Macromolecule

large molecules

How many bond can carbon form ?

4 covalent bonds (likes to BOND with hydrogen)

Types of Bonds Carbon can form

• single

• double

• triple bonds

What shape can Carbon containing molecules be found in?

• straight chain

• branched chains

• rings

4 Organic Macromolecules (biological molecules)

• Carbohydrates (CHO) : C6 H12 O6-glucose

• Lipids fats (CHO) ton of H

• Proteins (CHON) ton of H

• Nucleic Acids (CHONP)

Carbohydrates Monomer

monosaccharides (simple sugars)

Carbohydrates Molecular Formula

C6 H12 O6 (CHO)

Carbohydrates are used for..

short term energy

Monosaccharides - 1 sugar

• simple sugars

• glucose, fructose, galactose

• Benedicts Reagent- indicator used to detect simple sugars

  • when heated turns from blue-tan / orange-red

Disaccharides- 2 sugars

• made of 2 monosaccharides bonded together (thru dehydration synthesis)

• sucrose, lactose, maltose

• Chemical formula: C12 H22 O11

Polysaccharides- many sugars

• long chains of sugars

• complex carbs

• starch, glycogen, cellulose

Lipids

• fats, oils, & waxes

• hydrophobic (water hating) bc they’re no polar (no charge to the molecule)

• not a polymer

What are lipids used for

• energy storage (ex. fats)

• warmth (insulation)

• structure (ex. cell membrane)

• chemicals messengers (ex. steroid molecules)

Monomers of lipids

Glycerol + Fatty Acids

Proteins

• monomer: amino acid

• linked by peptide bonds

What 4 structures hold protein together?

• Primary structure

• Secondary structure

• Tertiary structure

• Quaternary structure

Nucleic Acid

your genetic material

Nucleic Acid Monomers

nucleotides

What 3 things is nucleic acids composed of?

• sugar

• phosphate group

• nitrogenous base

2 types of Nucleic Acids + functions

DNA = cell function, code protein, store information

RNA = transfer genetic information

Enzymes

• made up of proteins

• function as catalysts, which speed up chemical reactions by lowering chemical energy

Big Bang

• 10-20 billion years ago

• when universe was concentrated on 1 super dense mass that exploded

• hurled matter & energy into space

What was the primitive earth like?

• no oxygen

• volcanic

• mostly…

  • nitrogen

  • carbon dioxide

  • water vapor

  • hydrogen

Who were the scientists we discussed in class? (Origin of Life- Themed)

• Franceso Redi

• Louis Pasteur

• Alexander Oparin

• Miller & Urey

• Lynn Margulis

Franceso Redi

showed that maggots came from flys, not meat- disproved spontaneous generation

Louis Pasteur

used a swan neck flask to show microbes don’t appear unless exposed to air- supported bigenius (life comes to life)

Alexander Oparin

believed life began through chemical evolution in the “primordial soup” of Earths oceans

•  later tested by miller + urey

Miller & Urey

simulated early Earth’s atmosphere and energy (lightning)

• produced amino acids

Lynn Margulis

• eukaryotic cells came from prokaryotes living together

• mitochondria chloroplasts have their own DNA and reproduce on their own

Biogenesis

life coming from existing life

Spontaneous Generation

life arises from non-living matter (disproven)

6 Causes of Evolution

• mutation

• isolation

• gene flow

• genetic drift

• natural selection

• artificial selection

Mutation

change in DNA that creates a new trait

Gene Flow

genes for certain traits can go in and out of the population

Genetic Drift

“chance events” change the gene pool (sum of alleles)

Example of Genetic Drift

• disease

• natural disasters

Natural Selection

only the most adapted to the environment survive and reproduce

Isolation

members of a species become separated and can no longer mate

Artificial Selection

organisms are chosen to mate based on desired traits

What are the 5 evidences of ( r )evolution?

• embryology

• biochemistry

• adaptations

• fossils

• comparative anatomy

Embryology

shared features in embryonic development

What does embryology suggest?

common ancestry

Biochemistry

similarities in DNA, RNS and proteins

the more similar, the more related

Adaptations

body parts or process that help an individual survive and reproduce

Adaptations example

fur

Fossils

preserved remains of animal or plant

What are fossils used to understand?

how species changed over time

Comparative Anatomy (3 structures)

• Vestigial Structures

• Analogous Structures

• Homologous Structures

Vestigial Structures

body structures today that no longer serve a purpose

What is an Example of Vestigial Structures?

appendix

Analogous Structures

different structure same function between unrelated organisms

Homologous Structures

same structure, different function: shown in common ancestry

Example of Homologous Structures

forelimb of bat and human

What are the 3 categories of adaptations?

• Physical (fur)

• Behavior (hibernation)

• Internal (snake venum)

Who was Charles Darwin?

a naturalist

What did Charles Darwin discover?

natural selection on the Galapogus Islands

What was Charles Darwin’s theory?

organisms with traits best suited to the environment are mostly likely to survive and reproduce

Why was Darwin’s theory important?

shows how species change overtime

Prokaryotic Cells

• cells that do NOT contain any membrane bound organelles (little organs)

• NO NUCLEUS

• 1st life forms on earth

Eukaryotic Cells

• contain tons of membrane bound organelles (animals, plants, fungi, protists)

• mostly multicellular

• nucleus present

Plant Cells

a type of cell that makes up plants and can make its own food.

Plant cells include …

• chloroplasts

• cell wall

• central vacuole

Animal cells

a type of cell that makes up animals and does not have a cell wall or chloroplasts

Animal cells include…

• cell membrane

• lysosomes

• mitochondria

Cell Wall

• job: supports & protects cell

• structure:

  • made of carbohydrates & cellulose

  • stiff & strong

• both eukaryotes & prokaryotes

• plant

Cell Membrane

• job:

  • gives shape to cell

  • regulates what goes in and out (semi-permiable)

• structure:

  • outter barrier

  • made of fats called phospholipids. parts move like a liquid.

• both:

• prokaryotes & eukaryotes

• animal & plant cell

Nucleus

• job:

  • carries hereditary informations

  • controls all cells activities

• structure:

  • contains nucleoli & DNA

  • surrounded by nuclear membrane

• Eukaryotes

• Both animal & plant cell

Nucleolus

• job: RNA & Ribosomes are made here

• structure: round structure inside nucleus

• Eukaryotes

• Both animal and plant cell

Ribosome

• job: produces proteins

• structure:

  • made of RNA

  • located on the rough ER or in Cytoplasm

• Both:

  • eukaryotes & prokaryotes

  • animal and plant cell

Cytoplasm & Cytosol

• job:

  • surrounds organelles

  • location for chemical reactions

• structure:

  • gel like substance that fills the cell

• Both:

  • eukaryotes & prokaryotes

  • animal and plant cell

Cytoskeleton

• job: provide shape, organization & movement

• structure: a network of proteins

• Both:

  • eukaryotes & prokaryotes

  • animal and plant cell

Centrioles

• job: aids in cell reproduction

• structure: found in pairs and made of microtubules

• eukaryotes

• animal cell

Rough Endoplasmic Reticulum

• job: transports proteins

• structure: tubular membrane system with ribosomes attached to it

• eukaryotes

• both animal & plant cell

Smooth Endoplasmic Reticulum

• job: creates sx hormones and lipids

• structures: tubular membrane system with NO ribosomes attached to it

• both:

  • prokaryotes & eukaryotes

  • plant & animal cells

Glogi Apparatus

• job:

  • packaging plant

  • modifies, sorts, & packages proteins

• structure:

  • called apparatus, complex, or bodes

  • flattened sacs

• eukaryotes

• both animal & plant cell

Vacuole

• job:

  • stores food, water & wastes

  • supports the cell wall in plant cells

• structure:

  • large sized in plant cells (50%)

  • fluid filled sac

• eukaryotes

• both plant and animal cells

Lysosome

• job:

  • cell’s digestive system

  • breaks down worn out cell parts

  • defense under invasion

• structure:

  • vesicles and holds digestive enzymes

• eukaryotes

• animal cell

Chloroplast

• job:

  • traps the sun’s energy to make food (photosynthesis)

• structure:

  • contains green pigment chlorophyll

• eukaryotes

• plant cell

Mitochondria

• job:

  • provides energy for cell by converting O2/ fat/ protein

  • powerhouse of the cell

  • controls cell respiration

• structure:

  • double membrane (inner & outer layer)

  • vary in size & number

• eukaryotes

• both animal & plant cell

The Compound of Light Microscope-

What is the function of the diaphragm?

regulates the amount of light that passes through the specimen

If you want to change the objective lens through which you are viewing a specimen, what must you do?

spin the revolving nosepiece (you will hear a click)

What knob is turned to focus an image under low power?

coarse adjustment

What is the purpose of having a light source on a microscope?

allows light to reflect upward through the specimen and lenses

Explain the significance of the term “compound” in describing a modern light microscope

2 lenses → eyepiece & objectives

• allows for greater magnification and clearer detail

Identify the parts of the microscope that are used for supporting the specimen and holding it in place

Stage clips: hold it in place

Stage: supports the specimen