Genetic Variation And Its Control Flashcards
WHAT DO GENES CARRY
Genes carry the information that results in plants and animals having similar characteristics to their parents
WHY DO OFFSPRING RESEMBLE THEIR PARENTS
Offspring resemble their parents because they contain the genetic information passed on to them by their parents
WHAT IS ASEXUAL REPRODUCTION
Asexual reproduction needs only one parent to reproduce
- since there is only one parent, there is no fusion of gametes and no mixing of genetic information
- as a result offspring are genetically identical
WHAT ARE CHROMOSOMES AND GENES, WHAT DO THEY DO
Chromosomes are found in the cell nuclear and contain many genes
- a gene is a section of DNA which carries coding for a particular protein
- different genes control the development of different characteristics of an organism
INHERITED FACTORS
Variation due to genetics causes inherited variation
EXAMPLE
• eye colour
• hair colour
• skin colour
VARIATION DUE TO ENVIRONMENTAL FACTORS
Some variation within species is inherited, and some variation is due to the environment
— some are due to a combination of both
WHAT FACTORS CAN AFFECT THE CHARACTERISTICS OF ANIMALS
- climate
- diet
- accidents
- culture
- lifestyle
FEATURES THAT SHOW ENVIRONMENTAL VARIATION
- your language
- your religion
• flower colour in hydrangeas
(Blue flowers in acidic soil - pink flowers in alkaline soil)
WHAT ARE GAMETES
Sex cells
Male - sperm
Female - eggs
WHAT IS THE FUSION IF GAMETES CALLED
Fertilisation
Each human gamete contains 23 chromosomes
Asexual reproduction in plants can take a number of forms
Many plants develop underground food storage organs that later develop in the following years into plants
Learn
EXPLAIN ARTIFICIAL CLONING IN PLANTS
cuttings
Simplest way to clone plants is to take a cutting
- a branch from the parent plant is cut off and its lower leaves are removed and the stem planted in damp compost
- plant hormones are often used to encourage new roots to develop
- the cutting is then covered in a clear plastic bag at this stage to keep it moist and warm
- after a few weeks roots develop and a new plant is produced
STAGES OF AMIMAL CLONING
- The nucleus is removed from an unfertilised egg cell and discarded
- The nucleus is removed from an adult body cell and injected into an egg cell
- Am electric shock is provided to make the egg cell begin to divide to form an embryo
- Still in a ball of cells, the embryo is inserted into the womb of an adult female
- The embryo grows and develops
EXAMPLE OF ADULT CELL CLONING IN ANIMALS
Dolly the sheep was the first mammal to be cloned using adult cell cloning
BASIC IDEA OF EVOLUTION
The basic idea of evolution is that all species have developed over time from simple life forms over billions of years
WHAT IS NATURAL SELECTION
The process whereby organisms better adapted to their environment ten to survive and produce more off spring
WHAT IS DARWINS THEORY
- individuals In a species show a wide range of variation
- this variation is because of differences in their genes
- individuals with characteristics most suited to the environment are more likely to survive and reproduce
- the genes that allow these individuals to be successful are passed to their offspring
IN DARWINS THEORY, WHAT HAPPENS TO THOSE WHO ARE POORLY ADAPTED
They are less likely to survive or reproduce, which means their genes are less likely to be passed to the next generation.
Species eventually evolve
WHY DID PEOPLE NOT LIKE DARWINS THEORY
- it conflicted religious views
* not enough evidence
WHAT DID LAMARCKS THEORY INCLUDE
- A characteristic that is used more and more by an organism becomes bigger and stronger, and one that is not used eventually disappears
- Any feature of an organism that is improved through use it passes it to their offspring
