Week1: Introduction To Cells And Genetics Flashcards
What does the central dogma of molecular biology describe?
The pathway of information flow: DNA → RNA → protein.
What is a gene?
The segment of DNA sequence that codes for one protein (or one RNA molecule).
What is the definition of inheritance?
The passing of physical or mental characteristics genetically from one generation to another.
What is the structure that stores hereditary information in cells?
DNA (Deoxyribonucleic acid).
How many protein-coding genes do humans have?
Approximately 20,000 to 25,000.
What is the difference between diploid and haploid?
- Diploid = two copies of each gene (2n)
- Haploid = a single copy of each gene (n)
Who is known as the father of genetics?
Gregor Mendel.
What is Mendelian Genetics?
The study of inheritance patterns and the behavior of genes.
What is a dominant allele?
An allele that expresses its trait even in the presence of a recessive allele.
What is a recessive allele?
An allele that only expresses its trait when two copies are present.
Fill in the blank: The basic unit of heredity is called a _______.
[gene]
What is the phenotype of a heterozygote Rr?
Resembles the homozygote R.
What are the two processes through which cells reproduce?
- Asexual
- Sexual
What is a somatic cell?
Most human cells that reproduce by asexual means.
What is the expected ratio of phenotypes in the F2 generation when crossing two heterozygotes (Rr)?
3:1.
True or False: All cells in the human body are identical.
False.
What is the function of the cell membrane?
To enclose the cell and regulate the movement of substances in and out.
What is the significance of Mendel’s experiments with pea plants?
They established the foundational principles of heredity.
What is the role of RNA in the central dogma?
To act as a messenger that carries genetic information from DNA to the ribosome for protein synthesis.
Fill in the blank: The _______ is the basic structural and functional unit of all living organisms.
[cell]
What are the methods used to study genes and genetic information?
- Gene cloning
- DNA sequencing
- Genetic engineering
What is the chance of a child having Huntington’s disease if one parent has the mutation?
1:1 (50%) chance
What type of genetic disorder is Cystic Fibrosis?
Recessive allele disorder
What is the common mutation responsible for Cystic Fibrosis?
Mutation in the cystic fibrosis transmembrane conductance regulator (CFTR) gene
What is the incidence of Cystic Fibrosis in humans?
1 in 2,000
What is the chance of a child having Cystic Fibrosis if both parents are carriers?
3:1 (25%) chance
Define codominance in genetics
Alleles are codominant if one allele does not mask the other
What is incomplete dominance?
Phenotype of the heterozygote is an intermediary between homozygotes
What are the three alleles for ABO blood groups?
A, B, O
What is the genotype for Phenotype A in ABO blood groups?
AA or AO
What is the genotype for Phenotype B in ABO blood groups?
BB or BO
What is the genotype for Phenotype AB in ABO blood groups?
AB
What is the genotype for Phenotype O in ABO blood groups?
OO
What is the definition of a gene?
The unit of heredity
What is the difference between haploid and diploid?
Haploid = one copy of each gene; Diploid = two copies of each gene
What does homozygous mean?
Having two identical alleles (AA or aa)
What does heterozygous mean?
Having two different alleles (Aa)
What does it mean for an allele to be dominant?
It will be expressed even when there is just one allele
What does it mean for an allele to be recessive?
It will only be expressed when there are two alleles
Fill in the blank: The smallest unit of living organisms is the _______.
Cell
