Towson Partain Bio 120 Unit 2

What are the two types of chromosomal mutations?

Chromosomal number and chromosomal structure

What is the relationship between chromosome, allele, and gene?

Chromosomes are made from DNA. Genes are short sections of DNA. Alleles are different forms of a gene.

Structure, function, and definition of DNA

Functions: (cookbook)A molecule of heredity that stores info required for making all the proteins required in a cell. Double Helix, double stranded, deoxyribose, DNA condenses from chromatin into chromosomes

Allele

alternative versions of the same gene

Genome

The set of instructions on how to to make your cells, their components and their components' components

Sex chromosomes vs autosomes

any chromosome that is not a sex chromosome vs. a chromosome involved with determining the sex of an organism, typically one of two kinds.

What's the difference between benign tumors and malignant tumors?

benign —> has no effect on surrounding cells malignant —> invades surrounding cells

somatic cells

body cells mitosis: for growth/repair, makes identical copies

germ cells

sex cells meiosis: to make gametes (egg/sperm),makes unique cells ½ chromosomes * one of each type of chromosome

Stem Cell

A class of undifferentiated cells that are able to differentiate into specialized cell types. The two main sources are embryonic stem cells) and adult stem cells

What is the definition and purpose of a pedigree?

A diagram showing the lineage or genealogy of an individual and all the direct ancestors, usually to analyze or follow the inheritance of trait. Show different modes of inheritance like dominant or recessive traits as well as sex-linked It helps to figure out whether a person is a carrier for certain traits or diseases

Gene

A gene contains information about anything your body needs

cancer

Abnormal cell growth (A cell doesn't die when it should (apoptosis)) Cancer cells can invade other cells Can occur through genetic damage caused by environmental carcinogens, viruses, inheritance of genes, and sometimes we don't even know

What is the relationship between DNA, chromosomes, genes, genome, and protein?

DNA is found in the chromosome and chromosomes are found in genes gene < DNA< chromosome < genome

What are the similarities and differences between DNA replication & protein synthesis?

DNA replication results in the formation of a complementary strand by means of semi-conservative replication (one of the original strands will remain with the newly synthesised strand) whereas Protein synthesis results in the formation of amino acids and polypeptide chains. Both require RNA

What are structural mutations and what occurs within them?

Deletion - missing a gene Inversion - upside down gene Duplication - extra gene Translocation - traded gene with an other chromosome

Diploid vs. Haploid

Diploid contains two complete sets of chromosomes, one from each parent (2n) and Haploid have a single set of unpaired chromosomes (n)

What is an example of non-disjunction?

Down's syndrome i.e. trisomy 21 (three of the 21st autosome)

Meiosis

Occurs solely in sex cells The chromosome number reduces i.e haploid It produces 4 daughter cells (combined genetic material from both parents) Crossing over does take place

GMOs

GMOs are formed using Recombinant Technology - inserting genes from one type of organism into another which can Increase food nutritional value, Prevent spoiling,Prevent frost damage, Prevent plant diseases,Increase drought and salt tolerance,Reduce pressure on wild populations

Crossing Over

Gene for gene exchange of genetic information between members of a homologous pair of chromosomes during meiosis I

Homologous vs. nonhomologous

Homologous chromosomes are chromosomes that contain alleles for the same gene. Non homologous chromosomes contain alleles for different types of genes.

What's the difference, with regard to meiosis, between identical twins and fraternal twins?

Identical twins come from a single ovulated egg fertilized by one sperm and the embryo splits into two. Fraternal twins come from two ovulated eggs fertilized by different sperm

co-dominance vs. incomplete dominance

If a heterozygous genotype is present, then both phenotypes exist side-by-side vs. If a heterozygous genotype is present, then the phenotype is intermediate

Gene Therapy

Insert a normal gene into the appropriate cells of an individual affected with a genetic disease, thereby permanently correcting the disorder. A retrovirus (a virus rendered harmless) is used as a vector. It exploits the ability of the virus to insert DNA into the chromosomal DNA of its host cell.

What occurs during interphase, mitosis, cytokinesis?

Interphase DNA is copied, Mitosis DNA is split equally into two daughter cells, cytokinesis parent cell is cleaved in half

What is guiding the science community

Intrinsic value - value for its own sake has an end in itself and not as a means to a further end vs. Instrumental value - means to a further value i.e. to an end that may bring good to humans

What are his two laws of genetics?

Law of Segregation (from meiosis): Each organism has two hereditary units for each trait and during gamete formation, these units segregate from each other and pass into different gametes. Each gamete receives only one copy (allele). Law of Independent Assortment (from meiosis 1): In the formation of gametes, the distribution of hereditary units for one trait is INDEPENDENT of the distribution of hereditary units for the other unit. Different traits are inherited independently of each other.

What happens in meiosis I & meiosis II? (one sentence explanation for each)

Meiosis I - homologous pairs separate. Meiosis II - virtually identical to mitosis & serves to separate the sister chromatids of the replicated chromosomes from each other.

What is the main chromosomal number mutation and what does it do?

Non-disjunction and it involves the improper separation of chromosomes during cell division. In Somatic cells (mitosis) it only affects individual whereas in Germ (meiosis) it affects offspring

Nucleotides

Nucleotides are the building blocks of DNA (Deoxyribonucleic Acid). Each nucleotide is made of a phosphate, a sugar and a base. The nucleotides are connected to each other by phosphate to sugar bonds. These nucleotides are referred to as adjacent bases. These bonds are very strong. This forms the sugar-phosphate backbone of the DNA molecule. The hydrogen bonding occurs between complementary bases on opposite strands. Complementary bonding:A-T C-G

Mitosis

Occurs in somatic cells chromosome number remains the same It produces 2 daughter cells (identical chromosomes to the parent cell) no crossing over takes place

Cloning

Produces one or more organisms genetically identical to the "parent" that donated the single cell. Problems: Reduced genetic variation, Lifespan greatly reduced, 90% failure rate

Continuous Variation

Several genes working together producing many phenotypes for that trait

Know the ways in which diversity arises.

Sexual reproduction and random fertilization Genetic recombination (independent assortment and crossing over)

Chromosomes

Structural unit containing part or all of an organisms genome consisting of DNA and its associated proteins 22 pairs (sister chromatids) of autosomes and 1 pair of sex chromosomes. karyotype: A pictorial arrangement of a full set of an organism's chromosomes.

Can the environment affect genetics

The expression of genes in an organism can be influenced by the environment, including the external world in which the organism is located or develops, as well as the organism's internal world, which includes such factors as its hormones and metabolism.

Who is gregor mendel?

The father of genetics

Independent Assortment

The homologous pairs (one from mom & one from dad) are situated at the metaphase plate. The homolog's orientation is as random as a flip of a coin.

What is the purpose of an amniocentesis?

a medical term used when doctors remove fluid from the uterus of a pregnant woman for testing. The fluid withdrawn is called amniotic fluid; its purpose is to protect the unborn child. This fluid contains fetal cells and different chemicals from the baby.Detects chromosomal abnormalities

Lethal allele

a mutated allele that fails to code for a protein that is vital for life

How are RNA and DNA different and similar?

double helix vs. single stranded uracil vs. thymine ribose vs. deoxyribose stores information vs. helps DNA process that information

Genotype vs. Phenotype

genetic composition of an individual vs. physical traits

Homozygous vs. heterozygous

genotype where the alleles are the same vs. genotype where the alleles are different

Are the chromosomes condensed or not during these phases?

interphase -->uncondensed mitosis --> condensed cytokinesis --> condensed

Dominant vs. Recessive

when one allele completely covers up the other allele for a gene vs. when one allele is completely covered up by the other allele in a gene.

Where is a genome located?

within the chromosome