Genetics Flashcards
What is a gene and what is it’s importance to our human health?
A gene is a region of DNA strand that codes for some functional molecule. It’s a unit of heredity in a living organism.
we cannot function without our genes they contain all our genetic material.
Describe the double helix including the bases?
Double helix is like a ladder and consists of two parallel deoxyribose- phosphate supports along with a series of bases that make up the rungs of the ladder. DNA contains 4 bases: •Adenine (A) •Thymine (T) •Guanine (G) •Cytosine (C)
What is the difference between DNA & RNA & their roles in genetics?
DNA is where all the hereditary material is made & replicated.
mRNA; mRNA determine the amino acid composition of proteins, which constitutes in how the proteins hence the cell functions in a particular way.
RNA is primarily outside the nucleus in the cytosol & ribosomes.
DNA is located primarily in the nucleus.
Describe the anatomy and functions of a chromosome?
A chromosome is a mixture of DNA and protein- contains our genetic make up.
Each chromosome is made up of two chromatids joined by a centromere.
each uncleared cell in the body has 46 chromosomes arranged in 23 pairs. Woman have homologous pair of X chromosomes & men have heterologous pair X+Y chromosome.
Autosomes= rest of the chromosomes that determine physical characteristics.
What are the functions of nucleic acids?
The direction of all protein synthesis
The accurate transmission of this information from one generation to the next.
What is Protein synthesis?
It is the process in which cells make proteins.
Explain the process of Mitosis?
It is a process where a single cell divides into two identical cells (cell devision)
The major purpose of mitosis is for growth and to replace worn out cells.
describe features of the mitosis Interphase stage?
- the DNA in the cell is copied in preparation for cell devision, this results in two identical full sets of chromosomes.
Dominant allele vs Recessive allele?
Dominant allele is phenotypically expresses over another allele.
Recessive allele is only expressed in the absence of a dominant allele.
What is an allele?
Different forms of the same gene
What is a codominant allele?
Allow expression of both alleles
What is sex linkage in terms of genetic expression?
Phenotypic expression that is dependent on the gender & tied to the sex chromosomes
What is a phenotype?
Phenotype is what the thing looks like physically vs the genotype which is the genetic information (DNA etc)
What is a chromatin?
What is a chromosome?
Chromatin- housed in the nucleus
• made up of DNA packed around proteins
•found in all stages of cell cycle
•condenses during cell devision to become chromosomes
Chromosomes- single stranded groupings of condensed chromatin.
• replicates so each daughter cell receives correct number of chromosomes.
Mitosis vs meiosis?
Mitosis- results in body cells
Meiosis- results in sperm & egg cells (gametes)
Starting cells have 2 sets of chromosomes 46 in total.
