Studied by 14 people
Biology Terms and Definitions
Features of an AUTOSOMAL DOMINANT Pedigree
all affected have at least 1 affected parent
once the trait disappears in a branch it does not reappear
equals males and females
Features of an AUTOSOMAL RECESSIVE Pedigree
two unaffected parents can have an affected child
all children of two people with the condition must have the condition
a trait may disappear in a branch and reappear
equal males and females
Features of an X-LINKED DOMINANT Pedigree
a male with the trait gives it to all daughters no sons
female with trait may give it to all genders
all affected have at least 1 parent with the trait
if the trait disappears from a branch it doesn’t reappear
more affected females than males
Features of an X-LINKED RECESSIVE Pedigree
all the sons of a female with the trait are affected
a pattern can be: aft. male → non aft. daughter → aft. male
all children of two people with the trait will show the trait
more males than females
What are the blood types?
A, B, AB, or O(i)
What are inorganic molecules?
Molecules that are relatively small and usually do not contain carbon, e.g. water, oxygen gas, carbon dioxide, minerals, vitamins
What are organic molecules + examples?
Molecules that are relatively large and carbon-based, e.g. carbohydrates, lipids, fats, proteins, nucleic acids. These are macromolecules.
What are polymers?
macromolecules are polymers, meaning that they are made up of many repeating subunits that are similar or identical to each other.
What is the monomer of carbohydrates?
Monosaccharide
What is the monomer of lipids?
fatty acids and glycerol
What is the monomer of protein?
amino acid (20 diff types)
What is the monomer of nucleic acid?
nucleotide (stores biological information)
What is the backbone of a DNA strand?
Phosphate
What are the four nitrogenous bases in a DNA strand?
adenine, guanine, cytosine, thymine
What is the cell membrane made of?
2 Phospholipids with a hydrophilic head and hydrophobic tail
What does a nucleotide contain?
phosphate
pentose suger
nitrogenous base
What is the difference between RNA and DNA nucleotides?
The RNA nucleotide has ribose as the sugar, while DNA has deoxyribose (RNA also uses Uracil instead of Thymine)
What is RNA?
RNA contains the coded instructions that ribosomes use to build proteins (single stranded)
What is a chromosome
A strand of DNA that is coiled around histones
What are homologous chromosomes?
pair of chromosomes
same size and shape
one of each from both parents
What is a gene?
A section of a chromosome that codes for making a protein
What are alleles?
Different forms of the same gene
What is a genotype?
The genetic coding of an individual trait
What is a phenotype?
The physical expression of the genes/proteins that are produced
What does homozygous mean?
Possessing the same alleles for a given characteristic
What does heterozygous mean?
Possessing different alleles for a given characteristic
What is incomplete dominance?
When two parent’s phenotypes blend to create a new phenotype (one allele is not completely dominant over the other)
What is codominance?
When two parent phenotypes are expressed together in their offspring (neither are dominant or recessive)
How many chromosomes are in human eggs or sperm?
23
What do centrioles do during cell division?
They use spindle fibres to separate chromosomes at the equator of the cell
Explain the four steps of mitosis?
Prophase: Chromosomes condense, and spindle fibres begin to form
Metaphase: Chromosomes align in the cell's equator
Anaphase: Chromosomes are pulled apart to opposite sides
Telophase: Nuclear membranes reform around the separated chromosomes
Explain the steps of meiosis - stage one
Prophase I: Chromosomes condense, pair up, and exchange genetic material (crossing over)
Metaphase I: Homologous chromosome pairs align in the centre
Anaphase I: Homologous chromosomes are pulled to opposite sides
Telophase I: Two new cells form, each with half the original chromosome number
Explain the steps of meiosis - stage two
Prophase II: Chromosomes condense again in the two cells
Metaphase II: Chromosomes align in the centre of each cell
Anaphase II: Sister chromatids are pulled apart to opposite sides
Telophase II: Four genetically unique cells are formed, each with half the original chromosome number
What does it mean if a gamete has a haploid number of chromosomes?
It has half the number, or one set, of chromosomes in a regular (diploid) cell
What does it mean if a gamete has a diploid number of chromosomes?
It has the total number of chromosomes, or two sets, one from each parent
What is the acronym to remember the phases of cell division?
PMAT:
prophase
metaphase
anaphase
telophase
What is the difference between stage I and II of meiosis?
In stage I the chromosomes condense in homologous pairs and separate into one chromosome, and in stage II they separate into two chromatids
Outline what happens in the prophase of mitosis
centrioles migrate to the poles of the cell and produce spindle fibres
nuclear membrane breaks down
chromosomes condense and become visible in cytoplasm
chromosomes migrate to the equator of the cell
Outline what happens in the metaphase of mitosis
chromosomes line up at the equator head-to-toe
spindle fibres attach to the centromere of each chromosome
Outline what happens in the anaphase of mitosis
spindle fibres contract towards the centrioles
the chromatids are pulled apart towards opposite poles of the cell
Outline what happens in the telophase of mitosis
new nuclear membranes form around each group of chromosomes
spindle fibres break down
the cell membrane and cytoplasm splits into two cells
Interphase
Where DNA replication occurs
What is the outcome of mitosis
Two diploid daughter cells that are genetically identical to the parent cell are produced.
Location of cell division in multicellular organisms
In all body tissues - somatic cells
DNA Replication
produces copies of each chromosomes called chromatids
they are connected at the centromere to form double stranded chromosomes
doubles the amount of DNA in the nucleus to maintain diploid number over cell division
Transcription
The process of making a copy of the genetic codes in the DNA onto an mRNA
Where does transcription occur
The nucleus of the cell
Transcription requires:
free nucleotides to build the mRNA (A, U, G, C)
RNA polymerase that builds the mRNA molecule
What does RNA polymerase do?
Unravels and unzips the DNA and builds a molecule that is complementary to the DNA sequence
Translation
The process by which the genetic code on the mRNA is used as a blue print to make protein
Where does translation occur?
The ribosome of the cell
Note 
Flashcard (46)