Advertisement Upgrade to remove ads

Vocab for March exam for science you're welcome everybody

evolution

the process by which species gradually change over time.

Charles Darwin

an English naturalis. He studied the plants and animals of South America and the Pacific islands, and in his book On the Origin of Species by Means of Natural Selection (1859) set forth his theory of evolution.

HMS Beagle

the ship Darwin sailed on a 5 year trip around the world. He studied fossils (preserved remains of organisms) in Argentina and Brazil and zoology (types of animals) in the Galapagos Islands.

scientific theory

a statement that has been backed up by experimentation. It is not a fact. It is only as strong as its evidence!

diversity (how Darwin's trip changed his thinking)

an infinite number of animals and plants, each with adaptations suited to their environment.

fossils (how Darwin's trip changed his thinking)

older bones were similar but different to newer bones.

adaptations (how Darwin's trip changed his thinking)

animals from the same species appeared to develop traits to survive in new environments.

On the Origin of Species

Darwin's most famous book which contained observations from his trip.

theory of evolution

species gradually change over time to adapt better to their environment.

theory of natural selection

organisms better adapted to their environment will survive and reproduce-"Survival of the Fittest".

what causes natural selection to happen?

overproduction, variation, and competition. Changes to environment can affect an organisms ability to survive and can lead to selection.

overproduction

species that produce more offspring survive better.

variation

offspring differ from each other in many ways.

competition

a limited supply of food and other resources and presence of predators leads to competition between species.

evidence supporting theory of evolution

fossils, similarities in early development, DNA comparisons

fossil

the preserved remains of an organism

homologous structures

adaptations that organisms inherited from a common ancestor.

analogous structures

adaptations that are similar because of a common environment.

early development: organisms at birth

comparing animal fetuses shows similarities not obvious in adult form.

DNA comparisons

comparing animal DNA and gene makeup shows similarities not obvious in adult form.

branching tree

a diagram that identifies time points where new species are made. Shows how different organisms evolved from each other. Less levels of shared classification = bigger differences in appearance.

when do new species form?

when a group of individuals remains isolated from the rest of its species long enough to evolve different trait.

how do fossils form?

1) Animal dies and is buried under layers of sediments (particles of soil and rock)
2) Sediments harden to become rock and animal is preserved as a fossil
3) Rock erodes and fossil is exposed

types of fossils

petrified, molds/casts, preserved

petrified fossils

minerals soak into bones, turning them into rocks.

molds/casts

bones dissolve, leaving gaps.

preserved fossils

full animal stored in ice or other minerals.

relative dating

Fossils found higher on rock are younger than fossils found lower on rock.
Used to compare fossils.
Does not tell scientists actual age.

radioactive dating

Compare amount of radioactive element in fossil to amount of other elements in which it breaks down
Work backwards from present to calculate age.

radioactive element

unstable elements that decay (break down) into different elements.

half-life

time it takes for half the atoms in a sample to decay.

fossil record

the millions of fossils scientists have collected over time.

geologic time scale

calendar of Earth's History, created using radioactive dating from fossils.
Calendar goes backwards-starts millions of years ago, ends at present time.

unanswered questions about evolution

what causes mass extinctions?
do species evolve by gradualism or punctuated equilbria?

mass extinctions

scientists hypothesize (make an educated guess) that major climate change is responsible.

gradualism

evolution occurs slowly but steadily over time, which is how Darwin thought evolution occurred.

punctuated equilbria

the theory that species evolve by rapid changes separated by long periods of little or no change, which accounts for gaps in the fossil record.

organism

a living thing.

unicellular

made of one cell, such as bacteria.

multi-cellular

made of many cells, such as animals.

characteristics that all living things share

have a cellular organization, contain similar chemicals (water, proteins, carbohydrates, lipids/fats, and DNA), use energy, respond to their surroundings, grow and develop, reproduce.

stimulus

a change in an organism's surroundings that causes the organism to react.

response

a reaction or change in behavior.

growth

organisms use energy to get bigger

development

the process of change that occurs during an organism's life to produce a more complex organism.

reproduction

produce offspring through seeds, eggs, or clones.

theory of spontaneous generation

the mistaken idea that living things can arise from non-living things. Scientists found this by observing flies growing from dead meat.

classification

the process of grouping things together based on their similarities.

why do scientists classify?

to make organisms easier to study.

taxonomy

the classification of living things by similar traits.

Carolus Linnaeus

a pioneer of Taxonomy who developed organism naming system that is used today Each organism has 2 names: genus and species. 1st: Genus - Group of organisms that are closely related. 2nd: Species - Distinct feature of the species. Capitalize genus but not species.

taxonomic keys

are used to determine the identity of an organism. They use traits to classify organisms.

levels of classification

Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species (Didn't Kin
more levels two organisms share = more similar they are.

evolution and classification

species with similar ancestors and similar cell structure are classified more closely together.

domain

1st step on the classification ladder. Based on: cell type, make food/eat food, and number of cells in body.

autotroph

get food from sunlight/other chemicals.

heterotroph

get food from other organisms.

prokaryote

an organism without a nucleus in their cells.

eukaryote

an organism with a nucleus in their cells.

Domain Bacteria

prokaryote, unicellular, autotrophs and heterotrophs.

Domain Archaea

prokaryote, unicellular, autotrophs and heterotrophs.
Difference from bacteria: found in extreme conditions, heat, acid, salty, sewage.

Domain Eukarya

organisms have cells with a nucleus.
Divided into 4 kingdoms, protists, fungi, plants, animals.

Protist Kingdom

eukaryote, unicellular and multi-cellular (algae), autotroph and heterotroph.

Fungi Kingdom

eukaryote, multi-cellular (except for yeast) heterotrophs that digest food outside their body & then absorb it.

Plant Kingdom

eukaryote, multi-cellular autotrophs that absorb sunlight to make glucose.

Animal Kingdom

eukaryote, multi-cellular heterotrophs that capture and eat their food.

bacteria

unicellular prokaryotes.

cilia and flagella

move cell.

shape and size of bacteria

spherical shape, rod shape, and spiral shape.
size ranges from 1/1,000th of a meter to 1/1,000,000th of a meter.

reproduction of bacteria

asexual: binary fission
sexual: conjugation
endospore formation

binary fission

one cell divides to form two identical cells.

genetics

the study of heredity

inheritance

transmission of DNA from parents to offspring

Gregor Mendel

"The Father of Genetics." A priest and a gardener who cross-fertilized purple and white plants. First he found that all 4 of the F₁ generation was purple, then he found that 1 out of 4 of the F₂ was white.

trait

characteristic of an organism that is passed down, such as seed color or stem height.

fertilization

combine the sperm from one organism with the egg of another organism.

purebred

an organism that has the same alleles for a trait.

p generation

parent generation.

f₁ generation

offspring of the p generation.

f₂ generation

offspring of the f₁ generation.

allele

the different forms of a gene. Each organism must have 2 of these from each trait, one from Mom's and Dad's.

dominant allele

an allele whose trait always shows up in the organism when the allele is present. Represented by a capital letter.

recessive allele

an allele that is hidden whenever the dominant allele is present. Represented by a lowercase letter

gene

the factors that control a trait, a segment of DNA on a chromosome that codes for a trait.

heredity

the passing of physical characteristics from parents to offspring.

hybrid

an organism that has two different alleles for trait.

Punnett square

a chart used to predict the results of a genetic cross. Used to predict the outcome of meiosis

probability

the likelihood that something will happen. It is a prediction, not a fact.

genotype

the alleles of an organism.

homozygous

same alleles for a trait, purebred.

heterozygous

different alleles for a trait, hybrid.

phenotype

the physical appearance of an organism.

co-dominance

when two or more alleles have equal dominance, so hybrids show both alleles. Write these alleles as superscripts.

genome

all of the DNA in one cell of an organism.

chromosomes in a human cell

23 pairs-one from mom and one from dad.

chromosome

a structure in the nucleus that contains genetic material.

haploid

50% of DNA.

diploid

100% of DNA.

homologous chromosomes

chromosomes with matching information.

asexual reproduction

produce offspring with identical DNA from 1 organism-use mitosis.

sexual reproduction

produce offspring with DNA from 2 different organisms.

meiosis

the process that occurs in the formation of sex cells (sperm and egg) by which the number of chromosomes is reduced by half.

chromatid

each half of the chromosome.

centromere

holds the 2 chromatids together.

objective of meiosis

make a 4 sex haploid cells from a diploid cell where haploid contains 1 allele of each gene.

purpose of meiosis

to make 4 sex cells to pass on to the next generation.

How do we make babies with shared characteristics from each parent?

need to make cells with half of the DNA from each parent and then merge them into a new cell.

x and y chromatids

determine the gender of an organism.

xx

female.

meiosis 1: start

cell nucleus has 4 chromatids: 2 from mom and 2 from dad.

meiosis 1: prophase

cell makes copy of each chromatid-4 homologous chromosomes; mom and dad chromosomes swap similar genes.

meiosis 1: metaphase

mom and dad chromosomes line up in the center of the cell, and are held together by spindle fibers attached to the centromeres.

meiosis 1: anaphase

nucleus breaks down and chromosomes are pulled apart by spindle fibers-cell divides.

meiosis 1: telophase

cell ends up with two chromosomes each, having one allele of each gene from mom and dad.

meiosis 2

new cells split again to produce 4 new cells, with two chromatids each-1 chromatid from mom and 1 from dad.

what doesn't happen in Meiosis 2?

DNA does not copy.

DNA

deoxyribonucleic acid, contains genetic material in 2 strands.

nucleotide

a segment of DNA that consists of sugar, phosphate, and nitrogenous base.

sugar (deoxyribose)

foundation.

phosphate

connection between nucleotides.

nitrogenous base

code of DNA (adenine, thymine, cytosine, guanine)
adenine goes to thymine; cytosine goes to guanine.

relation between each strand of nucleotide

top strand is the reverse of the bottom strand.

how to copy DNA

top strand "unzips", give DNA to offspring.

mutation

an error of copying DNA. Errors can create new alleles. Can effect trait, phenotype, and chance of getting disease.

mutation

an error of copying DNA. Errors can create new alleles. Can effect trait, phenotype, and chance of getting disease.

RNA

ribonucleic acid, contains uracil instead of thymine in DNA. Assists in protein synthesis by carrying code from DNA to ribosome in cytoplasm.

Friedrich Miescher

In 1869, he discovers a white substance in the nucleus of cells.

Phoebus Levene

In 1920, he finds that DNA contains:
a) DNA Backbone: Deoxyribose Sugar and Phosphates
b)Nitrogen Bases (A, G, C, T)

Rosalind Franklin

In 1952, she takes X-ray photos of DNA and shows it looks like a helix.

James Watson and Francis Crick

In 1953, they use Franklin's data (without permission) to show that DNA looks like a double helix.

Where do organisms get each set of their genes?

From their parents (Mom and Dad).

cells

form the parts of an organism and carry out all of an organism's functions.

structure

what an object is made of and how its parts are put together.

function

the processes that enable it to stay alive and reproduce.

Robert Hooke

In 1660 he used his compound microscope to look at slices of cork. He saw boxes and called them cells because they looked like small rooms.

Anton van Leeuwenhoek

In 1673, he used a simple microscope and saw living things in pond and lake water.

Matthias Schleiden

In 1838, he saw that all plants were made of cells.

Theodor Schwann

In 1838, he saw that all animals were made of cells.

Rudolf Virchow

In 1855, he saw cells dividing to make more cells.

cell theory

1) All living things are made of cells.
2) Cells are the basic units of structure and function of living things.
3) All cells are made from other cells.

1st level of organization-cells

building block of all structures.

2nd level of organization-tissues

a group of cells that perform a specific function.

3rd level of organization-organ

a group of tissues that perform a specific job-heart.

4th level of organization-organ system

a group of organs that work together to perform a specific job.

organelle

a tiny cell structure that carries out a specific function within the cell.

cell membrane

holds organelles in cell
Controls transport in/out of cell-front gate.

nucleus

contains all code for:
Building new organelles.
Turning organelles on/off-control center.

mitochondria

respiration: Break down sugars to provide energy for cell-power source.

See More

Please allow access to your computer’s microphone to use Voice Recording.

Having trouble? Click here for help.

We can’t access your microphone!

Click the icon above to update your browser permissions above and try again

Example:

Reload the page to try again!

Reload

Press Cmd-0 to reset your zoom

Press Ctrl-0 to reset your zoom

It looks like your browser might be zoomed in or out. Your browser needs to be zoomed to a normal size to record audio.

Please upgrade Flash or install Chrome
to use Voice Recording.

For more help, see our troubleshooting page.

Your microphone is muted

For help fixing this issue, see this FAQ.

Star this term

You can study starred terms together

NEW! Voice Recording

Create Set