Genetics and Evolution Flashcards
What is genetics?
The study of the ways characteristics are passed on from one generation to the next
What are the types of characteristics?
⇒Inherited characteristics
⇒Non-inherited characteristics
What is an inherited characteristic?
It is passed on from one parent to the child by genes
e.g. Hair colour, blood type, petal colour
What is a non-inherited characteristic?
It is not passed on from parents
e.g. playing piano, accent, speaking a language
What are chromosones?
⇒They are thread-like structures made up of DNA and protein. ⇒Found in the nucleus.
⇒Humans have 46 chromosones (23 pairs)
What is a gene?
It is a short section of DNA in a chromosone
What is an allele?
2 different types of the same gene
e.g. dominant traits, recessive traits
What is a dominant trait?
It will show in a child if only one parent has the dominant gene
What is a homozygous trait?
When the ‘letters’ are either both capital or both small
e.g. DD, hh
What is a recessive trait?
It will only show if both parents pass on the recessive gene to the child
What is a heterozygous trait?
When the ‘letters’ are different
e.g. Dd, Hh, Bb
What is a genotype?
genetic makeup of an organism (letters)
What is a phenotype?
The physical makeup of an organism( appearance)
What is the success criteria of a genetic cross?
- Phenotype (M) + Phenotype (F)
- Genotype (M) + Genotype (F)
- Gametes
- Offspring genotype + phenotype
- Ratio + percentage
What is the chance a child will be a male or female?
50% chance
Which parent determines the sex of a cell?
Father
What is a mutation?
A change in a gene or chromosone. Leads to variation in a population
What is the relationship of mutations to an organism?
They can be helpful or harmful
-Harmful: Cystic fibrosis
What are the causes of mutations?
Environmental factors
-Smoking
-UV lights
-Radiation (x-rays)
What is variation?
the differences in characteristics between individuals of the same species
What is evolution?
the change in species over a long period of time
What is a species?
a group of organisms that can produce fertile offspring
What is natural selection?
the concept that species with characteristics helpful for survival will pass them on to offspring
What is diversity?
The variety of living organisms that exist on earth, also called biodiversity
What is an adaptation?
a characteristic of on organism that helps it to survive in its environment
What is meant by survival of the fittest?
Only the species that fit best into their environment will survive
How does evolution happen?
- More offspring are produced than needed. This leads to competition
- All populations of organisms contain genetic variations
- Those best adapted to their environment survive and pass on adaptations to their offspring
- New adaptations happen as the environment changes
- New species form over long periods of time
Who was Charles Darwin?
A British scientist who traveled the world on sea voyages, studying wildlife. He made suggestions as to how evolution happens, which became the thoery of evolution.
Name one observation and his conslusion (Charles Darwin)
opt.1. He noticed that animals frequently create more than they require for survival. He concludes it is challenging for living things to adapt to and survive in their enviroment
opt.2. Inherited variations occur in populations. He concludes that sexual reproduction allows for variation and the offspring become better adapted, pass on good characteristics and overall have a good chance of survival.
What did Darwin’s observations and conslusions lead to?
The theory of evolution
