bio keystone 2

Chromosomes

Humans have 46 \____in their somatic cells

Autosomes

First 22 PAIRS of chromosomes

Sex Chromosome

Last pair of chromosomes

Male

XY

Female

XX

The Cell Cycle

Period of time from the beginning of one cell division to the beginning of the next

M Phase (mitosis)

The division of the cell nucleus and cytokinesis

G1 phase

Intense growth and activity

S Phase

Copying of chromosomes

G2 Phase

Intense growth and activity and organelles and proteins required for cell division are produced

Mitosis-Asexual Reproduction

Produces somatic cells

Prophase

1st phase of mitosis where chromosome become visible and centrioles separate and take up positions on opposite sides of the nucleus;Nucleolus disappears;nuclear envelope breaks down

Metaphase

2nd phase in Mitosis where chromosomes line up in the middle of the cell and Microtubules connect the centromere of each chromosome to the poles of the spindle

Telophase

4th phase in mitosis where chromosomes become loose and begin to disperse, nuclear envelope reforms, spindle breaks apart, a Nucleolus reappears, and cytokinesis

Anaphase

3rd phase of mitosis where centromeres split, chromatids separate and become individual chromosomes, chromatids get pulled apart to the pole of the spindle, and ends when they stop moving

Meiosis- Sexual Reproduction

Produces gametes

Meiosis

A process of reduction division in which the number of chromosomes per cell is cut in half

Homologous

Two sets of chromosomes

Meiosis I

Chromosomes line-up similar to mitosis, except the homologous chromosomes for a tetrad and occurs during prophase I and 2 new cells are formed

Nondisjunction

Failure of homologous chromosomes to separate during meiosis

Meiosis II

Cells from meiosis I enter but don't undergo chromosome replication and anaphase II occurs

Spermatogenesis

Occurs in males to produce sperm; animals\=testes; flowers\=anther(stamen); produces haploid cells to fuse with an egg to form a zygote

Oogenesis

Occurs in females to produce eggs; animals\=ovary; flowers\= ovary(pistil); produces haploid cells to fuse with a sperm to form a zygote; only 1/4 of the haploid cells become the ovum

The Central Dogma

DNA-\>RNA-\>Protein

DNA

A molecule that carries genetic information which determines which proteins to make

Nucleotides are made of...

5 carbon sugar, a phosphate group, and a nitrogen base

Adenine pairs with...

Thymine

Guanine pairs with...

Cytosine

DNA Replication

Copying DNA ensuring that each resulting cell will have a complete set of DNA molecule

Differences between DNA and RNA

Deoxyribose-\>Ribose

Thymine-\> Uracil

Double Helix-\>Single Stranded

RNA

The intermediate between DNA and a protein

Transcription

The process of making RNA from DNA and happens in the nucleus of eukaryotes but in the cytoplasm of prokaryotes

RNA Polymerase

Scans the genome for the promoter region of DNA

Exons

Expressed message

Introns

In-between message that gets cut out of the mRNA to make the mature transcript

Alternative Splicing

Allows to mix-n-match exons to make different proteins from the same sequence

Translation

Matching an amino acid to the mRNA in order to make the protein code

AUG

Start signal

UAG,UAA,UGA

Stop signals

Mutation

A change in DNA sequence

Mutations in the DNA or RNA sequence produce...

The wrong amino acid sequence

Point Mutations

Change one or two base pairs

Frameshift Mutations

Change in the codon reading frame

Silent Mutation

The mutation goes unnoticed; doesn't change the sequence

Missense

An insertion, deletion, or substitution that would make the message different

Nonsense

Really bad; a stop codon is created and the message stops prematurely

Selective Breeding

Allowing only those animals with desired characteristics to produce the next generation

Genetic Engineering

Making changes in the DNA code of living organisms

Restriction Enzymes

Cuts DNA at a specific sequence of nucleotides

Recombinant DNA

Taking DNA and "pasting" it to another organism's DNA

Transgenic Organisms/Genetically Modified Organisms

Organisms that contain genes from other organisms

Clone

Member of a population or genetically identical cells produced from a single cell

Gene Therapy

The process of attempting to cure genetic disorders by placing copies of healthy genes into cells that lack them

Gene

A specific segment of the DNA molecule that codes for a specific protein(traits)

Allele

A form of a gene that is going to do what it's asked, but has different information

Law Of Dominance

States that some alleles are dominant and others are recessive

Law Of Segregation

Separation of alleles

Chromosome

A whole bunch of genes linked together into organized structure

Probablitity

Likelihood that a particular event will occur

Punnett Square

Diagram that helps determine gene combinations that might result from a genetic cross

Dominant Alleles

Allele that can mask other alleles and is represented with capital letters

Recessive Alleles

Allele that is masked and is represented with lower case letters

Homozygous

Have two identical alleles; true-breeding

Heterozygous

Have two different alleles; hybrid; carrier

Phenotype

Physical feature

Genotype

Genetic make-up

Independent Assortment

Genes segregate independently and do not influence each other's inheritance

Incomplete Dominance

One allele is not completely dominant over another

Codominance

Both alleles contribute to the phenotype of the organism

Multiple Alleles

Genes that have more than 2 possible alleles

Polygenic Traits

Traits that result from the interaction of many genes

Evolution

How species change over time in response to the environment

Natural Selection

The mechanism by which species evolve as proposed by Charles Darwin

Fossil Records

Studies history and reveals links between groups; evolutionary tree

DNA Analysis Or Molecular Biology

If 2 organisms share a common gene, they have a common ancestor; base pair differences show relationships

Morphology (body form)

Organisms may have similar structures but they are used in different ways

Vestigial Structures

Structures that are no longer used by the species

Speciation

The formation of new species over time as a result of evolution

Genetic Drift

A random change in the genes of a small gene pool

Migration

Permanent movement of gene into/out of a population due to interbreeding

Primary Succession

Occurs in a place where life has not existed previously

Secondary Succession

Occurs in a place where life has already existed

Abiotic Factors

Nonliving things in an environment

Biotic Factors

Living things in an environment

Limiting Factor

Something that, when limited, determines the carrying capacity of an ecosystem for a particular species

Carrying Capacity

The largest population than an environment can support at any given time

Producers

Make their own energy

Consumers

Get energy from eating something else

Mutualism

Both species benefit

Commensalism

One species benefits, the other is unaffected

Parasitism

One species benefits to the harm of the other

Predator Prey

One species catches and eats another

Competition

Both species want the same resource

Biogeochemical Cycles

The movement of abiotic factors between the living and Nonliving components within ecosystems

Individual

Just one species

Population

Group of organisms of the same species

Community

All living parts of an ecosystem

Ecosystem

Living AND Nonliving parts of an ecosystem