Science 2nd Semester Review

sexual reproduction

A reproductive process that involves two parents that combine their genetic material to produce a new organism

asexual reproduction

A reproductive process that involves only one parent and produces offspring that are identical to the parent.

What type of cell does sexual reproduction occur?

Sperm and Egg

What type of Cell does asexual reputation occur?

archaea and bacteria

What is the Advantages of sexual reproduction?

genetic diversity

What is a hapliod?

single set of chromosomes

What is a diploid cell?

has two sets of chromosomes (2n)

What is meiosis used for?

To create gametes

What is a gamete?

sex cell

What is Crossing over?

exchange of genetic material between homologous chromosomes

What is produced at the end of crossing over?

hybrid chromosome

Where do offspring get their chromosomes?

Parents

What are karyotypes?

picture of chromosomes

What is chromosome for a male and Female?

XY , XX

What is nondisjunction?

An error in cell division that causes homologous chromosomes or sister chromatids to move to the same side of the dividing cell

How are Genes, DNA and chromosomes related?

Genes are segments of DNA that code for proteins and are found on chromosomes

What are the characteristics of DNA?

Double-stranded. Uses thymine. Code for protein

What do RNA do?

Translate DNA code, Single stranded, Used Uracil.

Nucleotide structure

5 carbon sugar, phosphate group, nitrogenous base

Base pair rules

A pairs with T, C pairs with G

DNA replication

the process of making a copy of DNA

helicase

An enzyme that untwists the double helix of DNA at the replication forks.

polymerase I

removes the RNA primer and replaces it with DNA

polymerase III

Assembles new DNA strand in the 5' - 3' direction

single stranded DNA binding proteins

- bind to the unraveled strand preventing the re-association of the DNA strands & degradation of DNA by nucleases

sliding clamp

holds DNA polymerase in place

Leading Strand

the new complementary DNA strand synthesized continuously strand toward the replication fork in the 5' to 3' direction

lagging strand

The strand in replication that is copied 3' to 5' as Okazaki fragments and then joined up.

Okazaki fragments

segments of the lagging strand

Types of RNA

Messenger RNA (mRNA), Transfer RNA (tRNA), Ribosomal RNA (rRNA)

Messenger RNA

RNA that copies the coded message from DNA in the nucleus and carries the message into the cytoplasm

Tranfer RNA

type of RNA that transports amino acids to the ribosomes

RIbosomal RNA

type of RNA that combines with proteins to form ribosomes

What is a codon chart?

A chart of codon sequences that tells you what amino acid a codon sequence on the mRNA codes for. Puzzle piece.

What is the anticodon?

group of three bases on a tRNA molecule that are complementary to an mRNA codon

Where does protein synthesis occur?

ribosomes in the cytoplasm

What type of nucleic acid are involved in protein synthesis?

RNA

What is a mutation?

change in DNA sequence

substition mutation

A base in the DNA sequence is randomly swapped for a different base

insertion mutation

a mutation in which one or more nucleotides are added to a gene

deletion mutation

a mutation in which one or more pairs of nucleotides are removed from a gene

translocation mutation

one part of DNA breaks off and attaches to another chromosome

Genotype

genetic makeup of an organism

Phenotype

An organism's physical appearance, or visible traits.

Gregor Mendel 3 laws

Law of Dominance, Law of Segregation, Law of Independent Assortment

Law of Dominance

in a heterozygote, one trait will conceal the presence of another trait

Law of Segregation

one of the two gene copies present in an organism is distributed to each gamete

law of independent assortment

the law that states that genes separate independently of one another in meiosis

Complete dominance

a relationship in which one allele is completely dominant over another

incomplete dominance

Situation in which one allele is not completely dominant over another allele

Codominance

A condition in which both alleles for a gene are fully expressed

Multiple alleles

A gene that has more than two alleles

Sex-link inheritance

inherited through one of the sex chromosomes, which are the X and Y

Example of sex-linked inheritance

hemophilia and color blindness

Dihybrid crosses

mating experiment between two organisms that are identically hybrid for two traits

What is taxonamy

Study of classifying organism

Taxonomic hierarchy

Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species

How do you write Scientific names?

genus and species

Characteristics of kingdom Animalia

eukaryotic, multicellular, heterotrophic

Characteristics of kingdom plantae

eukaryotic, multicellular, autotrophic, sexual reproduction, cell wall: cellulose

Characteristics of kingdom Fungi

eukaryotic, multicellular, heterotroph, sexual reproduction, cell wall made with chitin

Characteristics of kingdom eubacteria

All unicellular, cell walls with peptidoglycan, ALL prokaryotic, some heterotrophic, some autotrophic,

Characteristics of Kingdom archaebacteria

unicellular, distinctive cell membranes, autotrophic, producing food by chemosynthesis, live in harsh environments

Characteristics of kingdom of protista

Eukaryotic, autotroph, or heterotroph, Most, are unicellular, some multicellular, some colonial, and some have cell walls, some have chloroplasts

Carl Linnaeus

"Father of Taxonomy"; founded the animal naming system of binomial nomenclature

Why have changes been made to taxonomic groups over the years?

Thing evolved and change

What was the first lifeforms on earth? Why?

ArchaeBacteria Because they can survive Harsh envirnments.

When did Earth form?

Hadean Era

When did the first cell appear?

Archaean Era

When did Photosynthesis First appear?

Archaean Era

When did exoskeleton first appear?

Proterozoic Era

When did the first eukaryotes appear?

Proterozoic Era

When did the first vertebrates appear?

Cambrian period

When did the amniotic egg first appear?

Carboniferous Period

When did the first Humans Appear?

Tertiary Period

What is natural selection?

The idea that the fittest survive and pass along their traits to their offspring.

How do mutations occur that lead to natural selection?

If a trait is advantageous and helps the individual survive and reproduce,

What are some causes of evolutionary change?

mutation, non-random mating, gene flow, genetic drift, natural selection.

What does it mean to be the fittest?

The ability to reproduction the most

What is evolution?

the process of change over time

Stabilizing Selection

The natural selection that favors intermediate variants by acting against extreme phenotypes

Directional Selection

occurs when natural selection favors one of the extreme variations of a trait

disruptive selection

favors individuals at both extremes of the phenotypic range

What is ecology?

The study of interactions between organisms and their environment

primary succession

succession that occurs on surfaces where no soil exists

secondary succession

type of succession that occurs in an area that was only partially destroyed by disturbances

What are decomposers?

Organisms that breakdown dead material for energy

Consumer

an organism that gets its energy by eating plants or animals.

Producer

An organism that can make its own food.

mutualism

both organisms benefit

Paraitism

A relationship between two organisms where one benefits and the other is harmed

Commensalism

one organism benefits and the other is unaffected

predation

An interaction in which one organism kills another for food.

food chain

A series of steps in which organisms transfer energy by eating and being eaten

food web

a system of interlocking and interdependent food chains.

energy pyramid

A diagram that shows the amount of energy that moves from one feeding level to another in a food web. Only 10% is pass on

Density dependent factors

limiting factor that depends on population size

density independent factors

limiting factors whose influence is not affected by population density

Niche

An organism's particular role in an ecosystem, or how it makes its living.

habitat

Place where an organism lives