Biology Review

Fall Semester

SCIENTIFIC METHOD AND LAB SAFETY

Ultimately, all scientific knowledge comes from:• both experimentation and observation

Hypothesis

• A hypothesis must be:• experimental

Independent Variable• A scientist testing the affects of a chemical on an

apple sprays an orchard with the chemical. A second orchard does not receive the chemical. In the fall, the number of apples harvested from each forest is counted. Which of the following is the independent (manipulated) variable in the experiment?

• the chemical• the number of apples• the first orchard• the second orchard

Inventions

Which invention played the biggest role in the discovery of cells by early scientists?

• compound microscope

SCIENTIFIC METHOD AND LAB SAFETY

• Ultimately, all scientific knowledge comes from:

• both experimentation and observation

Evidence

If a theory is challenged by new evidence, which of the following could occur?

• the theory could be altered.

Theories

Theories help scientists to:• propose new ideas about how the world

works

Smallest Unit

The smallest unit capable of carrying out life functions is:

• a cell

Lab Safety

What are good lab safety practices?• always wear goggles• no horseplay• never eat or drink during a lab.

• What are the steps of the scientific method?

All living things must:• maintain homeostasis

CELLS and CELL STRUCTURE

What are the main differences between plant and animal cells?

• plant cells have cell walls and chloroplasts, animals cells do not

Organelles

• Which organelles supply energy to the cell? (also known as the powerhouse of the cell)

• Mitochondria

Organelles

• Which organelles contain enzymes that break down old cell parts and defend a cell against viruses? (also known as suicide cells)

• Lysosomes

Cell Movement

• Which sentence best describes endocytosis?• contents enter a cell

Cell Movement

• Which sentence best describes exocytosis?• contents exit a cell

Organelles

• Which organelles are unique to plant cells?• Chloroplasts

Cell Theory

The cell theory states that all organisms are made of cells; cells are the most basic unit of life, and

• all existing cells are produced by other living cells

Cell Parts

What is the term for the jellylike substance that is contained inside the cell membrane?

• cytoplasm

Cell Parts

Unlike a eukaryotic cell, a prokaryotic cell does not have

• a nucleus

Cell Parts

Specialized structures that work together inside a cell are called

• Organelles

ATOMS, IONS AND MOLECULES

The smallest basic unit of matter is the • Atom

Carbon Based Molecules

The four carbon based molecules are:

• Lipids, proteins, amino acids, carbohydrates

Bonds

Atoms in molecules share pairs of electrons when the make

Covalent bonds

Acids and Bases

Which of the following solutions has the highest H ion concentration? (also most basic)

• solution with pH of 1• solution with pH of 4• solution with pH of 7• solution with pH of 10

Bonds

Substances are changed into different substances when bonds break and form during

chemical reactions

Energy

Chemical reactions that absorb more energy than they release (also speed up reactions at a lower temperature) are called…

catalyzed

DIFFUSION & OSMOSIS

Which of the following is NOT a type of passive transport?

• diffusion• osmosis• endocytosis• facilitated diffusion

DIFFUSION & OSMOSIS

• Which of the following phrases best describes active transport?

• moves substance against concentration gradient

• does not use chemical energy• forms a vesicle around a large particle• relies on diffusion of materials.

DIFFUSION & OSMOSIS

Transport proteins play a role in both

• passive and active transport

DIFFUSION & OSMOSIS

Diffusion is• net transport of molecules from a region of higher

concentration to one of lower concentration by random molecular motion.

• net transport of molecules from a region of lower concentration to one of higher concentration by random molecular motion.

• net transport of molecules from a region of higher concentration to one of lower concentration by specific molecular motion

DIFFUSION & OSMOSIS

• Osmosis is• diffusion of a solvent through a semi-permeable

membrane• diffusion of a solvent through a permeable

membrane• diffusion of a solute through a permeable

membrane• diffusion of a solute through a semi-permeable

membrane

DIFFUSION & OSMOSIS

A solute is • a solid material (like sugar or salt) dissolved in

another substance• a liquid material (like kool-aid) that is

dissolved in another substance.• a solitary material

DIFFUSION & OSMOSIS

A solvent is• a cleanser• a liquid or gas that dissolves a solid, liquid or

gaseous solute resulting in a solution.• a liquid or gas that dissolves only solids

resulting in a solution

Somatic Cells

• Also called Body Cells

• Make up most of your body tissues and organs

Germ Cells

• Are cells in your reproductive organs—ovaries and testes that develop into gametes.

• Gametes are sex cells -ova or eggs in female -sperm in male

Mitosis

• During which stage of the cell cycle is the DNA copied?

• Gap 1

Mitosis

• Mitosis can only happen in what type of cell?

– Eukaryotic cells

Mitosis

• The process where the cytoplasm divides and forms two new cells is called:

• cytokinesis

MEOSIS

Meiosis results in _____• 2 haploid daughter cells• 4 haploid daughter cells• 2 diploid daughter cells• 4 diploid daughter cells

Meiosis• Cell division to form the gametes, sperm (male

gamete) and egg (female gamete).• Characteristic of eukaryotes only: not in

prokaryotes.

• Normal cells are diploid: 2 copies of every gene.• Diploidy is useful because 2 copies of every gene

means that there a backup copy if one gets mutated. Mutations are very frequent in the cells of large organisms. We wouldn’t survive with just one copy of each gene.

• Gametes are haploid: 1 copy of every gene• Need to choose 1 copy of each gene randomly.• Why have sexual reproduction? Shuffling of

alleles between parents and offspring leads to new combinations. Bad combinations die without reproducing; good combinations survive and reproduce more offspring.

Result of Meiosis 1• Go from 1 cell to 2 cells. Each

daughter cell contains 1 copy of each chromosome: they are haploid, with the chromosomes still having 2 chromatids each.

• For humans: start with one cell containing 46 chromosomes (23 pairs) to 2 cells containing 23 chromosomes.

• As a result of crossing over, each chromosome is the mixture of the original homologues.

Meiosis 2• Meiosis 2 is just like mitosis• No replication of DNA between

meiosis 1 and meiosis 2. • Chromosomes line up individually

on the equator of the spindle at metaphase.

• At anaphase the centromeres divide, splitting the 2 chromatids.

• The one-chromatid chromosomes are pulled to opposite poles.

More Meiosis 2

Meiosis is a type of cell division that produces:

• zygotes• chromosomes• DNA• gametes

• Which process is best represented by the following chemical equation?

• Sugars + oxygen = carbon dioxide + water

PHOTOSYNTHESIS, CELLULAR RESPIRATION & FERMENTATION

Cellular Respiration

Before cellular respiration, glucose must be broken down by the process of

Photosynthesis

Cellular Respiration

The universal currency for energy in a cell is

ATP

ATP/ADP

The unit which has a phosphorus group taken away is called

• ADP

Cellular Respiration

• Which of the following groups of organisms uses cellular respiration in mitochondria to produce ATP for their energy needs?

• Plants only• Eukaryotes• Animals only• Prokaryotes• Lipids, proteins, nuclear reactants, oxygen

Fermentation

Fermentation does not produce ATP. Why is fermentation such an important process to cells?

• It allows glycolysis to continue to produce a small amount of ATP when oxygen is unavailable.

Cellular Respiration

Which of the following is a waste product (reactant) in photosynthesis?

• Oxygen• Glucose• Carbon dioxide• Carbon hydrotrioxide

CELLULAR REPRODUCTION

• Asexual reproduce is creation of offspring from

• One parent

Cellular Reproduction

In asexual reproduce the offspring is

• Genetically identical to each other and the single parent

Cellular Reproduction

Most prokaryotes reproduce through

• Binary fission

Cellular Reproduction

• Eurkayotes can reproduce asexually by all but one of the following:

• a. stem cutting• b. fragmentation• c. replication• d. cell differentiation

• Apoptosis is

• Programmed cell death

Cellular Reproduction

• How do most prokaryotes reproduce

reproduction

• How is mitosis different from binary fission?• a. mitosis is division of the cell nucleus• b. mitosis is involved in sexual reproduction• c. four daughter cells form in mitosis• d. the daughter cells formed by mitosis are

genetically differen

reproductionHow might asexually reproduction be beneficially

to a small animal in a widely scattered area?• a. it is more energy efficient than sexual

reproduction• b. both male and female offspring are

produced by asexual reproduction• c. the organism won’t have to spend time

looking for a mate• d. the organism won’t need a nucleus

reproduction

• What term describes a form of reproduction that involves gametes

• a. budding• b. fragmentation• c. vegetative reproduction• d. sexual reproduction

STEM CELLS AND CELL ORGANIZATION

Which of the following is correctly arranged from smallest to largest?

• a. tissue, cell, organ, organ system• b. organ, cell, organ system, tissue• c. organ system, organ, tissue, cell• d. cell, tissue, organ, organ system

Stem Cells

• What term describes the kind of stem cell that can grow into all cell types in the body?

• a. totipotent• b. pleuripotent• c. multipotent• d. adult stem cell

Homeostatis

How does communication between cells help maintain homeostatsis?

• a. coordination of activities are needed to maintain the body’s internal environment

• b. to know where to connect• c. to make other differentiated cells• d. coordinated cell division