Biology unit test

Gene

Short segment of DNA that controls expression of trait

Hormones

Proteins critical for transportation

What makes organism uniques

Order of nitrogen base in DNA

Double helix

Shape of DNA

Chromosomes

Coiled DNA inside nucleus carries genetic information for specific set of traits in genes

DNA stands for

déoxyribonucléic acid

Somatic cells

Body cells have 46 chromosomes or 23 pairs, diploid have two replicates, made by mitosis

X and Y chromosomes

Somatic cells 23rd pair but can have different number of x or y détermine sex

Gamete

Sex cells only found in ovaries or testes, 23 chromosomes haploid means only single copy, meiosis,

Interphase stages

Growth 1 phase, Synthesis phase, growth 2 phase

Growth 1 phase

Cell makes new molecules + grows larger, duration of growth varies depending on type + health of cell

Synthesis stage

Chromatin (uncoiled chromosomes) are duplicated form sister chromatids held together by centromere

Growth 2 phase

Synthesize more molecules grows larger

Contact inhibition

‘Normal’ cells stop dividing when coming into contact with like cells

Chemotherapy

Halt cell division

Cancer drugs

Damage RNA or DNA induce cell suicide (apoptosis)

Cell-cycle specific drugs

Kill when dying

Cell-cycle non-specific drugs

Kill cancer cells resting

Normal cells affected by chemotherapy

Blood cells, mouth cells, stomach + bowel, hair

Side effects of chemotherapy

low blood counts, mouth sores, nausea, diarrhea, hair loss

Mitosis

P: sister chromatids are visible M: line up A: pulled apart T: new nucleus

DNA

molecules in cell has instructions make other cell parts

Who made double helix model and when and what was their first mistake and how did they fix it

James Watson and Francis Crick in 1953 thought paired like with like (A with A) but then didnt result in uniform width of DNA molecule, found needed specific pairing

What does DNA look like

Anti parallel strands that twist around each other

What unit is DNA made of

Nucleotides, basic unit of nucleic acid

What are nucleotides made of

Sugar (deoxyribose), phosphate group, one of four nitrogen bases

4 nitrogen bases

Adenine (A), Guanine (G), Cytosine (C), Thymine (T)

Nitrogen base pairs

Apples in the tree (A to T), Car in the garage (C to G)

What are the nitrogenous base pairs held together by

Hydrogen bonds, AT have two, CG have three

Rosalind Franklin DNA discovery

X-ray crystallography found two antiparallel sugar phosphate backbones paired in DNA’s molecule interior

Karyotype and use

Taken picture of chromosomes used to diagnose disorders

Allele

Variations on gene

Homologous chromosomes

Identical chromosomes in length, centromere location and banding pattern, one from each parent, alleles found on same gene of these chromosomes

How many alleles for hair color gene

4

double single blue stick from each parent with brown background image from slides

diploid and unreplicated (single stranded), autosomes and sex chromosomes

Beginning interphase somatic cells

When are sex chromosomes homologous

Only in females, x chromosome

Autosomes

First 22 pairs of homologous chromosomes

Transparent background realistic ish chromosomes grainy pinched in middle

Double replicated chromosomes, look like x with sister chromatid connected by centromere, somatic cells visible in prophase also starting cells make gametes in ovaries + testes

White background single sticks from which karyotype is it with black lines in single sticks

Gamete haploid and unreplicated, 23 chromosomes, after fertilization zygote get diploid unreplicated

What is n

Indicate # chromosome copies in species ie humans n = 23

How are chromosomes arranged in karyotype

Largest to smallest by size

gametogenesis

meiosis

What is the starting and ending cell type in meiosis?

Starts with 1 diploid cell (2n) from either ovaries or testes and ends with 4 haploid daughter cells (n)

Reduction division

Homologous chromosomes separated make haploid cells

What happens in Meiosis I

Nuclear membrane dissolves, centrioles, P1: chromosome pairs w/ homologous form tetrad, crossing over happens, M1: still forming tetrad homologous pair chromosome line up tetrad double line A1: pull pair apart reduction division T: nuclear membranes MIGHT cytoplasm divides

Meiosis II

Mitosis but two haploid cells are coordinated nuclear membrane reforms

Tetrad

homologous chromosomes pair up

Crossing over

the exchange of genetic material between homologous chromosomes during Prophase I of meiosis like switching shoes

Is meiosis a cycle

No

Spermatogenesis

Meiosis form 4 sperm cells

Oogenesis

Meiosis 1 egg cell 3 polar bodies contribute cytoplasm make one large egg cell

which one have haploid ending cell which one diploid in mitosis vs meiosis

Haploid meiosis cells, diploid mitosis

what occurs in zygotes and most body cells

Mitosis

Part of cell division that produces growth

Mitosis

Promotes variation among offspring

Meiosis

Ensures same number of chromosomes between generations

Mitosis

Sister chromatid

two identical newly replicated chromosomes joined by centromere

Trisonomy

person has three copies of chromosomes (weird)

genetic variation methods

Independent Assortment, Crossing Over, Non-disjunction Chromosomal Mutations, Structural Chromosomal Mutations, Nucleotide Point Mutations

Law of Independent Assortment 

when different traits don’t depend on each other to show up

Non-disjunction chromosomal mutation

Sister chromatids or homologous chromosomes refuse to seperate resulting in n + 1 or n - 1

Polyploidy

Extra sets of chromosomes

Structural chromosomal mutation, four main types

Mutation in chromosome structure, deletion, duplication, inversion, translocation

Nucleotide point mutations

Mistake in DNA replication cause addition, substituition or deletion of nitrogen base pair

Purebred

Homozygous dominant

F1

First fillial generation (kids)

genotype vs phenotype

genetic makeup vs appearance

test cross

Determine genotype of individual showing dominant trait by making them have babies with a homozygous recessive

Incomplete dominance 

When dominant allele doesn’t commit and red and white flower make pink flower, but also two alleles are equally dominant

Codominance

Both alleles dominant shows up at the same time (red and white cow)

Why focus on x linked genes

Because x chromosome bigger than y has more alleles

Mendel’s laws of inheritance 

Law of segregation, law of independent assortment, genes located on chromosomes

Law of segregation

Ability of chromosomes in meiosis to be pulled apart randomly

Must be autosomal recessive because two unaffected parents have affected child

Dominant because two affected have unaffected

recessive because two unaffected have affected kid then all kids get it

dominant because two affected parents have unaffected child

example of trisonomy

Down syndrome

synthesis of new DNA

another way to just say DNA replication

precipitate

Two chemicals mix together to form a solid

translocation

when one homologous chromosome pair’s chromosome does crossing over with another homologous chromosome pair (ex. Chromosome 1 pair crossing over with chromosome 15 pair)

difference between point mutations and missense mutations 

point have no effect on protein making but missense make non-working protein 

what number start out in interphase end in mitosis and meiosis

start 4n end mitosis 2n and meiosis n