Topic 17 (Inheritance) Flashcards
How is DNA organized inside cells?
*Deoxyribonucleic acid or DNA is a molecule that carries
genetic information.
*The information is important for all cellular functions, such
as cell division and differentiation.
Describe the structure of a DNA molecule.
*A DNA molecule consists of two parallel strands. The two strands are joined by nitrogen containing or
nitrogenous bases.
*There are four bases: adenine (A) cytosine (C), guanine (G), and thymine (T).
How are chromosomes, genes and proteins related?
A DNA molecule carries many genes along its length. Each gene is a segment in the DNA that controls the production of a particular protein, enzyme, membrane carrier or neurotransmitter.
How is a protein made?
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How do genes control cell function?
*The nucleus in every cell contains all the genes to construct the human body.
*Genes can be switched on or off to form different types of cells. This is the process of differentiation.
What is mitosis?
Mitosis is a type of nuclear division. It produces daughter nuclei which contain the same number of chromosomes as the parent nucleus.
What are stem cells?
*Stem cells are unspecialised cells. They divide and produce new cells by mitosis.
*The daughter cells can be differentiated into specialised cells for specific functions in the organs where they
are found.
What is the importance of mitosis?
*Mitosis ensures that the resulting two daughter cells are genetically identical to the parent cell.
*This is important for processes such as
-growth in multicellular organisms;
-repair of damaged tissues;
-asexual reproduction.
What is meiosis?
*Meiosis is a type of nuclear division.
*The daughter nuclei contain half the number of chromosomes as the parent nucleus.
What is the difference between a haploid nucleus and a diploid nucleus?
Haploid cells are those that have only a single set of chromosomes (23 chromosomes in humans), while diploid cells have two sets of chromosomes (46 chromosomes in humans).
What is the importance of meiosis?
*Meiosis produces haploid gametes for fertilisation.
*Meiosis produces gametes that are genetically different.
What is genetics?
Genetics is the scientific study of heredity.
Geneticists are scientists who study genetics.
What is monohybrid inheritance?
Monohybrid Inheritance
is the inheritance involving one pair of contrasting traits,
such as:
*single or double eyelids;
*straight or curly hair;
*attached or detached earlobes.
What are alleles?
*Different forms of the same gene are called alleles
*If a person has two different alleles, the allele that is expressed is called the dominant allele, while the other allele that is not expressed is called the recessive allele.
What are genotype and phenotype?
*If a person has both recessive alleles, then the recessive phenotype will be expressed.
*Different combinations of alleles are called genotype.
*The expressed characteristic or outward appearance is called phenotype.
