Topic 6- Inheritance, Variation and Evolution

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Khloe

Cards (79)

What are chromosomes?
Long molecules of DNA (which contain genetic information).
What do genes code for?
A specific protein- sequence of amino acids.
What are genes?
Small sections of DNA that are found on a chromosome.
What is a genome?
The term for the entire set of genetic material (DNA) in an organism
Why is it important to understand the human genome? Examples?
Medical advancements.
Able to identify genes that are linked to different types of diseases/ inherited diseases.
What cells does sexual reproduction produce?
Genetically different cells.
What are the female gametes?
Eggs.
What is the male gamete?
Sperm.
How many chromosomes does a human gamete have?
23 chromosomes
Does sexual reproduction involve meiosis or mitosis?
Meiosis.
What happens in sexual reproduction? Why?
The fusion of male and female gametes.
Because there are two parents and the offspring will contain a mixture of their parents' genes.
What does the mixing of genetic information create in offspring?
Variation.
What cells does asexual reproduction produce?
Genetically identical cells
How many parents are in asexual reproduction?
1
Is meiosis or mitosis involved in asexual reproduction?
Mitosis
What is it called when the offspring is genetically identical to the parent?
Cloning.
What is the process of meiosis?
Duplication of the genetic information in the cell made.
Chromosomes arrange themselves into pairs.
In first division, the chromosomes line up in the centre of cell.
The cell is divided into two.
In second division, cells are lined up again and then each chromosome is pulled apart into singular alleles.
End up with a set of four gametes that are genetically different.
What happens to the cell produced by gamete fusion (meiosis)?
Makes identical copies of itself using mitosis.
What chromosomes do males have?
XY
What chromosomes do females have?
XX
What do the genes you inherit control?
The characteristics you develop.
What's the term for 2 identical alleles?
Homozygous
What's the term for 2 different alleles?
Heterozygous
Is the dominant characteristic shown as upper case or lower case?
Upper case.
Is the recessive characteristic shown as upper case or lower case?
Lower case.
What is the phenotype?
The observable characteristics or traits of an organism.
What is a genotype?
Internal genetic make up.
What allele is cystic fibrosis caused by?
Two recessive alleles for cystic fibrosis.
What is cystic fibrosis?
A genetic disorder which causes thick mucus in air passages and pancreas.
What allele is Polydactyly caused by?
A dominant allele
What is polydactyly?
A genetic disorder where a person is born with extra toes or fingers, it's not life-threatening.
How can embryos be tested for genetic disorders?
Prenatal testing and screening (in the womb).
Reasons for embryonic screening?
Stop people suffering with the condition.
Treating the disorders is expensive.
There are laws to stop the testing from going too far- selecting the gender of the baby.
Reasons against embryonic screening?
Implies that people with genetic disorders are 'undesirable'.
Could turn into a situation where everyone wants to test their embryos and pick desirable traits.
Screening is expensive.
What is the definition of variation in offspring?
Organisms of the same species that have genetic or environmental differences.
What is genetic variation?
Genetic variation refers to the differences in the genetic makeup of individuals within a population.
What is environmental variation?
Differences in the environment that can affect the phenotype of an organism.
What are mutations?
Changes in the DNA sequence (genome).
What is the Theory of Evolution?
All of today's species have evolved from simple life forms that first started to develop over three billion years ago.
Who came up with the theory of evolution?
Charles Darwin