Genetics Unit test Flashcards
DNA stands for what?
Deoxyribosenucleic Acid
Where is DNA located in the body?
DNA is located in the nuclei of your cells.
How big is your Nucleus
About 10 nanometers wide
What is the structure of DNA?
DNA is a double helix structure which is 2nm by 2m
What is Histones
Histones are the protein DNA wraps around
What are Gametes?
Unique cells that are made to reproduce
What are gametes a result of
Meiosis
Gametes have how many chromosomes?
23
What is the process called Oogenesis?
The formation of an egg or Oocyte cell
How many egg cells are created in one lifetime
400-500
When does meiosis begin for males?
It begins at puberty
How many sperm cells are produced each day?
Millions
Does the sperm or egg determine the genetic sex of the offspring?
Sperm
What factors play a role in determining the offspring?
Temperature, age, social structures, and fertilization alternate sex determination
What is Nondisjunction
Abnormal Meiosis
Name all the phases of Mitosis
- Interphase
- Prophase
- Metaphase
- Anaphase
- Telophase
- Cytokinese
What happens during Interphase
This is when cells do their jobs that contribute to daily functions. They grow and develop. This is also when DNA in the cell is being duplicated
What happens during prophase
Chromosomes are visible during this phase because they are condensing. The nucleus is still visible and present.
What happens during Metaphase
Spindle fibers attach to chromosomes. Chromosomes line up in the middle of the cell. M for middle
What happens during anaphase
Chromosomes divide into two sets. Each half or set is pulled away to opposite sides of the cell. Sister chromatids are separated.
What happens during telophase
Two nuclear membranes begin to form. The cell begins to separate
What happens during cytokinesis
Cytoplasm divides. Two daughter cells with the same number of chromosomes.
With respect to the whole cell cycle, how often do cells divide (Mitosis) and how often are they doing Interphase
They are doing interphase 90% and mitosis 10% of the time
How many chromosomes do humans have
46 chromosomes
What are centromere
The centromere is part of the chromosomes where the sister chromatids are held together.
What are chromatids
Chromatids are strands of replicated chromosomes.
What are spindles
Spindles help move the chromosomes/ chromatids. These spindles are fibers.
Meiosis does what?
Makes sperm and egg cells (gametes)
How many chromosomes do sperm and egg cells have?
23
What happens in prophase one
Along with what was previously stated. Chromosomes find their homologous pair. This means they are roughly the same size and share the same types of genes in the same location. The chromosomes then transfer genetic DNA.
What happens in Metaphase 1
The chromosomes go to the middle. The difference between this and mitosis is the chromosomes are in pairs.
What happens in Anaphase 1
The chromosomes are pulled away by the spindle fibers
What happens in Telophase 1
It is apparent you will end meiosis one with two new cells then cytokinesis follows splitting the cytoplasm but this process is not over.
What happens in prophase 2
Spindles start to form
What happens in Metaphase 2
In metaphase 2 the chromosomes line up in the middle but this time they are not in pairs.
What happens in Anaphase 2
The chromatids are pulled away by the spindle fibers
What happens in telophase 2
In telophase 2 the nuclei begin to appear and cytokinesis splits the cells into 4 new gametes
at what stage in mitosis do you have two distinct haploid cells
telophase 1
how does the production of gametes in biological males differ from biological females?
Male: Takes place in the testes, Begins at puberty, and continues throughout life.
Produces four sperm cells from each spermatocyte during spermatogenesis.
Sperm cells are small, highly mobile, and adapted for delivering genetic material to the egg.
Female; Takes place in the ovaries, Begins before birth, pauses during childhood, and resumes at puberty. It continues until menopause, but only one mature egg is typically produced per menstrual cycle, Produces one mature egg from each oocyte during oogenesis, The egg (or ovum) is relatively large and immobile, as it carries nutrients for potential fertilization and early embryonic development.
What is Genetics
the science that studies how genes are transmitted from one generation to the next.
What is a Gene
A segment of DNA that controls a hereditary trait.
What are Medels three Laws
The Law of Dominance and Recessiveness
The Principle of Segregation
The Principle of Independent Assortment
Mendel’s great contribution was to demonstrate that
inherited characteristics are carried by genes.
The Law of Dominance and Recessiveness
some alleles, which are variants of a particular gene found at the same chromosomal locus or location, are dominant over the other alleles for a given gene.
The Principle of Segregation
describes how pairs of gene variants are separated into reproductive cells.
The Principle of Independent Assortment
describes how different genes independently separate from one another when reproductive cells develop
A genotype is
the genetic makeup of an organism.
A phenotype is…
the physical characteristics of an organism – what the organism looks like.
the presence of the gene is not all that is required for the expression of a trait. The gene must be present along with the proper
environmental conditions
Some genes appear to:
blend. This is known as:
incomplete dominance or nondominance.
There are three alleles that determine blood type. What are they?
iA, iB and i
What blood types are recessive and what are dominant
A and B are codominant and i is recessive
What is polygenic inheritance
the determination of a given characteristic is the result of: the interaction of many genes. Some traits, such as size, height, shape, weight, color, metabolic rate, and behavior are not determined by one pair of alleles
What are Autosomes
Autosomes are all of the chromosomes within a cell except for sex chromosomes
Sex-linked traits include:
color blindness, hemophilia, and muscular dystrophy
