biology semester 2 study guide

what is Robert Hooke (1665) known for?

what is Robert Hooke (1665) known for?

given credit for identifying and naming cells; was looking at a piece of nonliving cork, thought that it looked like there were tiny rooms on it, so he called them cells

give an example of a prokaryote

bacteria

characteristics of prokaryotic cells

1. no nucleus

2. no membrane-bound organelles

characteristics of eukaryotic cells

1. nucleus with DNA

2. membrane bound organelles

your body is made of approximately _____ cells

30-40 trillion

there are approximately ____ different types of cells in the human body

200

define diffusion

process by which particles tend to move form an area where they are more concentrated to an area where they are less concentrated

define osmosis

diffusion of water

organelle composed of numerous membranes that carry out photosynthesis in plant cells; contains chlorophyll; solar energy for Cell City

chloroplast

rigid structure surrounding plant cells; gives protection, support, and shape to cells of plants, algae, fungi, and bacteria; city wall for cell city

cell wall

jellylike substance inside cells that contains molecules, and in some cells, organelles; eukaryotic cells- all cellular contents outside the nucleus; in prokaryotic cells- all the cell’s contents

cytoplasm

sacs which divide some materials from the rest of the cytoplasm; small organelle that contains and transports materials within the cytoplasm; taxi service for cell city

vesicle

organelle (sac) that is used to store materials such as water, food, or enzymes, and pigments needed by the cell; storage unit for cell city

vacuole

stack of flat, membrane-enclosed spaces containing enzymes that process, sort, and deliver proteins; post office and UPS of cell city

golgi apparatus

supplies energy to the cell by making ATP; the powerhouse of cell city; bean-shaped organelle that has its own ribosomes and DNA

mitochondria

storehouse for most of the genetic information, DNA; the town hall of cell city; double membrane

nucleus

links amino acids to form proteins; farm or food-producing factory of cell city

ribosome

property of biological membranes that allows some substances to pass across it while others cannot

selectively permeable

any specialized structure that performs important cellular functions within a cell

organelle

network of proteins (microtubules and microfilaments); gives cells its shape; tracks for movement of organelles; building material for cell city; rebar the ground

cytoskeleton

what does iso mean?

same

what does hyper mean?

above

what does hypo mean?

below

process of diffusion in which molecules pass across the membrane through cell membrane channels without using ATP

facilitated diffusion

relatively constant internal physical and chemical conditions that organisms maintain

homeostasis

substance that is dissolved in a solution; lesser amount

solute

the dissolving substance in a solution; greater amount

solvent

difference in the amount of a substance in one area compared to another area

concentration gradient

when ATP (energy molecule) is needed to move molecules across a membrane

active transport

(adenosine triphosphate) compound used by cells to store and release energy

ATP

principal pigment of plants and other photosynthetic organisms

chlorophyll

what does the greek “photo” mean?

light

what does the greek “synthesis” mean?

put together

fermentation is anaerobic. how many ATP molecules are produced after fermentation is completed?

2

fermentation lab (yeast, sugar, water): what products were created in the fermentation lab we did in class?

carbon dioxide and ethanol

cell that can divide for long periods of time while remaining undifferentiated

stem cell

process by which a cell divides its nucleus and contents

mitosis

to spread by transferring a disease-causing agent from the site of the disease to other parts of the body

metastasize

common name for a class of diseases characterized by uncontrolled cell division

cancer

stem cells are unique because

they divide and renew themselves

remain undifferentiated in form

develop into a variety of specialized cell types

apoptosis

programmed cell death

the creation of offspring from a single parent and does not involve the joining of gametes is known as

asexual reproduction

_____ tumors are clustered and can be removed

benign

asexual reproduction in prokaryotes that produce two identical daughter cells is known as __ ____

binary fission

substances known to promote cancer are called ____

carcinogens

____ tumors can metastasize and form more tumors

malignant

two known carcinogens

tobacco smoke and radiation

sequence of DNA that codes for a protein and thus determines a trait; factor that is passed from the parent to offspring

gene

scientific study of heredity

genetics

sex cell; haploid

gamete

having 2 identical alleles for a particular gene

homozygous

having 2 different alleles for a particular gene

heterozygous

physical characteristics of an organism

phenotype

genetic makeup of an organism

genotype

different forms of a gene

allele

trait controlled by 2 or more genes; ex. human eye color

polygenic trait

term used to refer to chromosomes in which one set comes from the male parent and one set comes from the female parent

homologous

process in which the number of chromosomes per cell is cut in half through the separation of homologous chromosomes in a diploid cell

meiosis

the modern science of genetics began with the work of an Austrian scientist and priest/monk named _____

Gregor Mendel

the basic unit of DNA is called a ____ it contains a ____, ____, and _____.

nucleotide; nitrogenous base, sugar, and phosphate group

four bases found in DNA

adenine, thymine, cytosine, guanine

what 2 men were given the nobel peace prize for discovering the double helix shape of DNA?

Watson and Crick

the organelle that helps a cell translate an mRNA message into a polypeptide

ribosome

building block of protein; attached to a tRNA

amino acid

process of copying a nucleotide sequence of DNA to form a complementary strand of mRNA

transcription

sequence of 3 nucleotides for one amino acid

codon

process by which mRNA is decoded and a protein is produced

translation

change in the DNA sequence

mutation

set of 3 nucleotides in a tRNA molecule that binds to a complementary mRNA codon during translation

anticodon

an agent that causes a mutation

mutagen

characteristics of DNA

1. contains the sugar deoxyribose

2. ACGT

3. typically double-stranded

characteristics of RNA

1. contains the sugar ribose

2. has the bases A, C, G, and U

3. single stranded

a type of RNA that carries copies of instructions for the assembly of amino acids into proteins from DNA to the rest of the cell

mRNA

a type of RNA that carries each amino acid to a ribosome during protein synthesis

tRNA

a good example of how an operon works is the lac operon. it is turned on and off like a switch. when ___ is absent from the environment, the lac operon is switched ____ to prevent ____ of the lac genes and save the cell’s ___

lactose; off; transcription; resources

point mutation

gene mutation in which a single base pair in DNA has been changed

frameshift mutation

mutation that shifts the “reading frame’ of the genetic message by inserting or deleting a nucleotide

selective breeding

allowing only the animals or plants with wanted characteristics to produce the next generation

PCR

the technique used by biologists to make many copies of a particular gene

recombinant DNA

DNA produced by combining DNA from different sources

evolution

change in a species over time; process of biological change by which descendants come to differ from their ancestors

natural selection

mechanism by which individuals that have inherited beneficial adaptations produce more offspring on average than do other individuals

uniformitarianism

theory that states the geological processes that shape earth are uniform through time

example of homologous structure

human hand and bat wing

example of analogous structure

butterfly and bat wings

example of vestigial structure

whales- pelvic bone and hind limbs

3 facts about Charles Darwin

1. British naturalist

2. sailed HMS Beagle for 5 years

3. examined creatures found on Galapagos Islands

gas exchange

nares

eardrum- hearing

tympanum

opening into the lungs

glottis

connects the pharynx to the ear; equalizes pressure in the frog’s inner ear

eustachian tube

throat

pharynx

connects the mouth to the stomach; food tube

esophagus

pump blood

heart

makes bile and other enzymes to help break down food

liver

stores bile for digestion

gallbladder

holds and digests food

stomach

absorbs nutrients from the food to be transported in the blood stream

small intestine

secretes digestive juices

pancreas

stores blood cells

spleen