Topic 3 genetics, 10 Flashcards
Interphase
The cell makes extra sub-
cellular parts, such as
mitochondria and ribosomes.
DNA replication also occurs,
to make copies of all the
chromosomes.
Prophase
The nucleus starts to break
down and spindle fibres
appear.
Metaphase
Chromosomes line up on the
spindle fibres across the
middle of the cell.
Anaphase
Chromosome copies are
separated and moved to
either end of the cell on the
spindle fibres.
Telophase
A membrane forms around
each set of chromosomes to
form nuclei.
Mitosis
The process of cell division.
Cells replicate their DNA and then divide to produce 2 identical cells.
Cytokinesis
The cell surface membrane
forms to separate the two
cells.
In plant cells the cell wall
forms.
How many chromosomes in human’s body?
46 chromosomes, 23 pairs
Gemetes ( sex cells )
Exception is sex cells (gametes) that only have one
of each pair.
As you inherit half your genes from each parent.
Therefore, the nucleus contains 23 chromosomes.
Meiosis
Only takes place in reproductive organs of
animals and plants.
Meiosis results in sex cells, gametes.
First stage of Meiosis
The first stage involves mitosis as the cell must
first replicate.
These two cells then divide to form gametes,
each with a single set of chromosomes.
Mitosis vs Meiosis
Only one cell division occurs.
Mitosis
Mitosis vs Meiosis
Genetic information is copied.
Mitosis/ Meiosis
Mitosis vs Meiosis
Four daughter cells produced.
Meiosis
Mitosis vs Meiosis
One copy of each chromosome
goes to each of the new daughter cells.
Meiosis
Mitosis vs Meiosis
Two daughter cells produced
Mitosis
Mitosis vs Meiosis
The cells produced are identical.
Mitosis
Mitosis vs Meiosis
Used to form gametes.
Meiosis
Mitosis vs Meiosis
Two cell division occur.
Meiosis
Nucleus
Nucleus: the central part of a cell that contains genetic material (DNA), acting as the control center for
the cell’s activities and cell division.
DNA
DNA: the molecule that stores genetic information in the cell and provides instructions for making
proteins and controlling the cell’s activities.
Chromosome
Chromosome: thread-like structures in cells that carry genetic information (DNA) and determine an
organism’s traits.
Gene
Gene: contains instructions for building and maintaining an organism; they determine an organism’s
characteristics.
Genome
Genome: A genome is the complete set of an organism’s genetic material, including all its genes and
DNA sequences, which carries the instructions for the structure and function of that organism.
Haploid
Haploid: Haploid refers to cells with half the normal number of chromosomes, typically found in
gametes.
Diploid
Diploid: cells that have a complete set of paired chromosomes, representing the full chromosome
number typical for an organism.
Fertilisation
Fertilisation: the process by which the sperm cell and egg cell fuse to form a zygote, initiating the
development of a new organism.
Zygote
Zygote: the cell formed by the fusion of sperm and egg during fertilization, which eventually develops
into a new organism.Zygote
Mitosis
Mitosis: a type of cell division that makes two identical cells, used for growth and repairing damaged
tissues.
DNA, chromosomes, polymer
A chemical known as deoxyribonucleic acid (DNA),
which is packaged into long molecules called
chromosomes
DNA is a polymer, a long molecule made up of
many repeating subunits, coded for by amino
acids.
A Gene
A gene is a small section of DNA that controls the
characteristics of your body, or more specifically
proteins.
Genes are grouped together on chromosomes.
Male or Female
Males have one Y
chromosome and one
X chromosome.
Females have two X
chromosomes.
A Genome
The genome of an organism is the entire
genetic material of the organism.
Includes all the
chromosomes and the
genetic material.
So, the human genome
includes all
46 chromosomes
Diploid
If it has the complete genome of 46 chromosomes,
it is diploid or 2n.
If it has half the genome, for example
Haploid
If it has half the genome, for example in a gamete cell,
it is haploid or 1n.
Diploid vs Haploid
Diploid vs. Haploid
These names refer to how many chromosomes a cell has.
Fertilisation
Is the fusion of the sperm and egg cell, which
includes the fusion of the nuclei.
So the offspring has a full genome.
The fertilised egg cell is called a zygote.
This then forms a ball of cells eventually
becoming an embryo through mitosis.
What is inherited variation?
Offspring get a mixture of characteristics from their parents.
We say they inherited these characteristics. Variation in this characteristic is known as inherited variation.
What is Gregor Mendel known for?
Founded the science of genetics.
Identified rules on how gratis are passed through generations of living things
What were Mendel’s 4 rules that he determined based on his findings?
Flower colour, plant height, and seed shape were controlled by pairs of heritable factors that come in different versions.
One version of a factor ( the dominant from) could mask the presence of another version ( the recessive from)
What is an Allele?
The factors controlling different characteristics were inherited independently of one another.
Recall that Alleles are different form of a gene.
- Each allele results in a different protein, for example the gene for dimples may have the dimple (D) of the no- dimple (d) allele in place.
Dominant Allele
Controls a character when only present on one of your chromosome ( CAPITAL)
Recessive Allele
To control the characteristics needs to be present on both chromosomes ( lowercase)
What does heterozygous mean?
If heterozygous for a gene, you carry 2 different alleles. For example … Aa
What does homozygous mean?
If homozygous for a gene, then carry 2 copies of the same allele. For example AA or aa
Chromosomes
Chromosomes consist of DNA is tightly coiled and
packaged up with proteins
Structure of DNA
A molecule of DNA contains two strands.
The strands are joined together by pairs of bases.
It then twists to form this helix shape.double helix
Nucleotide and bases
A nucleotide consists of alternating sugar and
phosphate sections.
One of four bases– A, C, G, or T– is attached to
each sugar.
(A - T, C-G)
Nucleotides
It is a polymer, a long
molecule made up of
many repeating
subunits, called
nucleotides.
Hydrogen Bonds
The bases in DNA are
joined by hydrogen
bonds.
DNA coding
A sequence of three bases is the code for a
particular amino acid. The three bases are called
a codon
The order of bases controls the order in which
amino acids are joined together to form a
particular protein.
Lesson 5
Була практична, як роздобути ДНК полуниці
Lesson 6
Науковці
Protein
Protein molecules of made up of long chains of Amino
Acids. There are around 20 different amino acids,
different arrangements
of these give different
proteins.
Structure of protein
Structure of Proteins
Proteins are macromolecules
(polymer).
Macro = Large
Very large molecules, created through
polymerisation (joining) of smaller subunits.
These subunits are different amino acids
(monomers).
Protein chain
- The long protein chain of amino acids is then
folded to make a 3D structure with a specific
shape. - This allows other molecules to fit into it – very
important for antibodies and enzymes.
Functions of Proteins
Structural Components
Hormones
Antibodies
Catalysts
Structural Components
Structural Components
For example, the structural components of
tissues such as muscle and tendons.
Hormones
Hormones
Hormones are chemical messengers in the body.
Examples include;
* Insulin
* Oestrogen
* Progesterone
* Testosterone
* Adrenalin
Antibodies
Part of immune system, involved in destroying
pathogens.
Catalysts ( enzymes)
Increase the rate of chemical reactions.
Stages of Protein Synthesis
Transcription and Translation
Transcription
Transcription
Takes place in the nucleus, the base sequence of
DNA is copied (transcribed) into mRNA
(messenger RNA).
Translation
Translation
The mRNA is then used as a template, to form
the amino acid chain or polypeptide.
What does monohybrid inheritance mean?
Monohybrid Inheritance study of how the alleles of just one gene are passed from parents to offspring
What does genotype mean?
Genotype - set of genes responsible for a particular characteristics
What does phenotype mean?
Phenotype - the observable characteristics resulting from the genotype
What are genetic disorders
Not all diseases are infectious. Sometimes diseases are the result of a problem in our genes and can be passes on from parents to child this is a genetic disorder
What is polydactyly, and how is it caused?
Polydactyly
Born with extra fingers or toes. Caused by a dominant allele, can therefore be inherited from just one parent.
