Bio quiz two

Mendel's four hypothesis

1. Alternative version of genes called alleles 2. For each character, two alleles are inherited 3. If two alleles inherited differ then one determines the appearance of phenotype 4. A sperm or egg carries one allele for each charecter because allele pairs segregate during meiosis

Hemophilia is an X linked recessive condition characterized by excessive bleeding w injury. A woman who Carrie's the gene but is not affected marries a normal man, what percentage of the couples sons is expected to have hemophilia?

50%

During DNA replication, a DNA strand is copied to make a new DNA molecule composed of two DNA strands. This new molecule contains

50% of the parents DNA

diploid cell

A cell containing two sets of chromosomes (2n), one set inherited from each parent.

cell cycle control system

A cyclically operating set of molecules in the eukaryotic cell that both triggers and coordinates key events in the cell cycle.

Epidemiology is the study of the origin of diseases, how they spread, and how to prevent their spread. Why was covid-19 considered a pandemic yet the H5N1 bird flu was not

A disease is named a pandemic when new incidences of the disease increase,spread rapidly, and with a very wide global distribution

Genome Graph

A network if DNA sequences typically from 1k or more individuals in which each individuals genome is a different path through the network

X-linked inheritance

A pattern of inheritance in which a recessive gene is carried on the X chromosome, so that males are more likely to be affected

Karyotype

A picture of all the chromosomes in a cell arranged in pairs

The Cancer Genome Atlas (TCGA)

A project to sequence the genomes of many different cancers to identify the types of mutations that develops

What are possible causes of epigenetic changes

Addition of methyl and/or acetyl groups, environmental factors, nicotine and alcohol

Hydrogen bonds in DNA

Bonds that form between the nitrogenous bases that form the "rungs" of the DNA ladder (generally weak but many create a stronger hold)

Oncogene

Cancer-causing genes that are formed due to mutations

Chemotaxis

Cell movement that occurs in response to chemical gradient of a substance or extra cellular signal

March 2022

Complete genome deciphered for the first time (~8% hidden)

Central Dogma of Molecular Biology

DNA -> RNA -> Protein

Daughter Cells

Each have a parental strand and a new complimentary strand (very complex)

Gregor Mendel

Father of genetics, pea experiments

J. Craig Venter

First to sequence bacterial genomes (Haemophilus influenzae) especially the whole genome sequence

Photo 51

First x-ray diffraction of DNA taken in 1952 by Rosalind Franklin, identified structure of DNA as a double helix (X shaped on X-ray)

Mitosis and Meiosis

G1: growth prior to DNA replication S: DNA replication G2: interval after DNA replication M: Mitosis/Meiosis

Why is inheritance of so many traits difficult to explain using only mendels view of genetics

Mendel was correct for the traits he investigated, but his principles must be extended (not discarded) to explain more complex patterns of inheritance.

A researcher treats cells with an inhibitor that prevents chromosomes from separating, this would trap the cell in what phase

Metaphase

Introns

Noncoding segments of nucleic acid that are spliced out of mRNA before it is translated

Exons

Nucleotide sequence encoded by gene that remains after introns removed and is translated in ribosomes

What aspect of tRNA makes it well suited for its function?

One part of the molecule attaches to RNA, another to the amino acid

Crossing over

Process in which homologous chromosomes exchange portions of their chromatids during meiosis.

During which phase of meiosis does crossing over and formation of tetrads occur

Prophase 1

The process of the human genome project was determined in part by which of the following methodologies

Shotgun sequencing

CAR T cell therapy

T cells are removed from a patient and modified so that they express CAR receptors specific to the patient's particular cancer. The T cells, which can then recognize and kill the cancer cells, are reintroduced into the patient.

sugar-phosphate backbone

The alternating chain of sugar and phosphate to which the DNA and RNA nitrogenous bases are attached

If a gene has the sequence AATTCGCG, what would be the sequence of an miRNA that turns off the gene?

The gene will be transcribed as the mRNA sequence UUAAGCGC; an miRNA of sequence AAUUCGCG would bind to and disable this mRNA.

Helical Structure

Two anti-parallel strands and not three based on width with bases on inside and the periodicity of repeating structural patterns

Rosalind Franklin and Maurice Wilkins

Used x-ray crystallography to study DNA structure

Infectious diseases that can be specifically transmitted from other vertebrate animals to human are called

Zoonotic diseases

sickle cell anemia

a genetic disorder that causes abnormal hemoglobin, resulting in some red blood cells assuming an abnormal sickle shape (autosomal recessive)

Gene

any interval along chromosomal DNA that is transcribed into functional RNA that is translated into protein

Hershey-Chase Experiment

confirmed that DNA is the genetic material because only radiolabeled DNA could be found in bacteriophage-infected bacteria

James D. Watson and Francis Crick

described the DNA molecule from Franklin's X-rays, proposed that DNA had a specific pairing between nitrogen bases (A-T) & (C-G) model pairing

Fred Sanger

developed the first method of DNA sequencing fast enough to sequence large genomes

Mary-Claire King

discovered the BRCA1 gene that causes breast cancer (hereditary)

James Allison and Tasuku Honjo

discovery of cancer therapy by inhibition of negative immune regulation

James Allison and Tasuku Honjo

discovery of cancer therapy by inhibition of negative immune regulation (identified key proteins on T cells called immune checkpoint proteins that are naturally responsible for turning off activated T cells)

Checkpoint mechanisms

ensure each phase is completed properly before the next one begins

A-T and C-G

found by Erwin Chargaff

Genome 10K Project

genomics project to sequence 10,000 vertebrate genomes to create a genome scale family tree to study evolution and adaptation

tumor suppressor genes

make proteins that stop cell division and kill cells (avoid cancer)

Advantages of genome graphs

more accurate and complete model ability to identify unique variants may identify mutations missed by single reference genome captures more regions than previously

Nucleic Acid

polymer of nucleotides; the genetic material of organisms (base sugar and phosphate)

George Gamow

predicted each word in the genetic code contains three bases

adenine and guanine

purines

thymine, cytosine, uracil

pyrimidines

What is cancer?

uncontrolled cell growth