science vocab unit 2

DNA

A complex molecule containing the genetic information that makes up the chromosomes.

RNA

single-stranded nucleic acid that contains the sugar ribose

nucleus

Control center of the cell

nuclear pores

small holes in the nuclear envelope where the RNA leaves from

cytoplasm

the material or protoplasm within a living cell, excluding the nucleus.

ribosome

Makes proteins; RNA travels here after being in nucleus

rough ER

proteins are modified here before they are packaged into vesicle and sent into the cytoplasm

vesicle

Small membrane-bound sac that functions in moving products into, out of, and within a cell.

golgi body

where proteins are completed

cell membrane

A cell structure that controls which substances can enter or leave the cell.

protein

A three dimensional polymer made of monomers of amino acids.

mitosis

1->2 new cells, creates identical cells, new cells have identical fulls sets of DNA

meiosis

1->4 cells, 4 genetically unique cells, creates gametes that combine to create new individuals, 1/2 of the og DNA

gametes

sex cells

punnet squares

used to predict the outcome of sexual reproduction

genotype

genetic makeup(DNA)

pheotype

visible traits

transcription

DNA to RNA

translation

RNA to protein

DNA synthesis

DNA to new DNA (copies DNA)

nucleotides

monomers of nucleic acids

nucleic acids

DNA and RNA

amino acids

monomers of proteins

monomer

building block

polymer

finished product

adenine

The base that pairs with Thymine in DNA, and Uracil in RNA

thymine

The base that pairs with Adenine in DNA

guanine

The base that pairs with Cytosine

cytosine

The base that pairs with Guanine

uracil

Nitrogen base that pairs with adenine in RNA.

codon table

shows all possible codons & the amino acid each codes for

mRNA

messenger RNA; instructions to make a protein

rRNA

ribosomal RNA; goes out into cytoplasm & it coils up in a Z part shape to make a ribosome

tRNA

transfer RNA; finds the correct amino acids & brings it to ribosome

chromatin

Substance found in eukaryotic chromosomes that consists of DNA tightly coiled around histones

genes

sections of DNA that code for a unique protein

chromosome

loose coiled DNA that are actively being used

centromere

Area where the chromatids of a chromosome are attached

sister chromatids

original chromosome duplicated & the two are attached at centromere

homologous chromosomes

Pair of chromosomes that are the same size, same appearance and same genes.

Heterozygous chromosomes

Chromosomes that have a different sequence of genes and a different structure.

prophase

first phase, chromosomes are visible & nucleus has dissolved

metaphase

chromosomes line up in middle of cell

anaphase

sister chromatids move to opposite sides of cell (apart)

telephase

DNA is now in two identical nuclei but still in one cell

spindle

equator of cell (middle)

cytokenesis

physical division of the cytoplasm, membrane & organelles into two new cells

PMAT I

Prophase I, metaphase I, anaphase I, telophase I- first stage of meiosis

PMAT II

Prophase II, metaphase II, anaphase II, telophase II- first stage of meiosis, with two cells instead of one

crossing over

homologous chromosomes overlap & swap

karyotype

picture of chromosomes-arranged from largest->smallest

monosomy

missing a chromosome

trisomy

having an extra chromosome

amniocentisis

prenatal diagnosis in which amniotic fluid, taken from a needle inserted into the uterus, is analyzed to detect certain genetic and congenital defects in the fetus.

diploid

full set of DNA (from both parents combined)

haploid

half of the DNA (only from 1 of 2 parents)

somatic cell

any cell of a living organism other than the reproductive cells.

frame shift mutation

a nucleotide is added or deleted, which changes the entire protein sequence

substitutions

point mutations that replace one nucleotide with another; can be harmful or harmless

silent mutations

harmless mutations

alleles

versions of the same gene

simple dominance

cross of two genes in which one is dominant over recessive

co-dominance

both alleles for a gene are expressed

multiple alleles

an allele of a genetic locus having more than two allelic forms within a population

incomplete dominance

one allele is not dominant over another, they combine

environmental influence

gene influenced by environmental factor

polygenic inheritance

multiple genes determine the phenotype of a trait

sex-linked traits

traits controlled by gene located on sex chromosomes

sexual selection

extreme traits in males of a species used to attract mates or compete for mating opportunities. traits can have drawbacks, but lead to better chance of reproudction

artificial selection

humans select traits in organisms

stabilizing selection

the average trait is the most useful

directional selection

extreme traits are favored

speciation

the formation of new species