Inheritance Flashcards
What is a chromosome made up of:
DNA
Define a chromosome:
A thread-like structure in the nucleus
What does a duplicated chromosome consist of:
Two identical chromatids
Hows chromosomes does a human have:
46 chromosomes (23 pairs)
How many sex chromosomes does it have:
2 chromosomes (1 pair )
What two chromosomes does a male cell have:
X and Y
What two chromosomes does a female chromosome have:
X and X
From where do you inherit the 46 pairs:
23 from each parent
What does DNA stand for:
Deoxiribonucleic Acid
How many strands does DNA have:
Two
Desscribe the structure of DNA
Double helix structure
How are the bases held together:
Via hydrogen bonds
What is a nucleotide:
The strand
What is a nucleotide made up of:
A phosphate, a sugar (called deoxyribose) and a base
What is the backbone of DNA made up of:
Sugar (deoxyribose) and phospate subunits
What does Adenine pair up with:
Thymine
What does Cytosine pair up with:
Guanine
Name the four bases:
Adenine, Thymine, Cytosine and Guanine
Define DNA:
A large molecue that makes up chromosomes and contains genetic information (genes)
Define genes:
A small section of DNA of a chromosome that has the code for making a protein
Explain how genes cause characteristics:
The gene is made up of amino acid which are arranged in a particular order in the protein. These proteins cause characteristics
Define genetic code:
The rule code by which the information encoded in the DNA sequence is translated into the amino acid sequence
Explain how genetic code works:
Each chromosome contains thousands of genes. A gene is a segment of DNA that contains the information for making a protein, which are a chain of amino acids. the information for making a particular protein and contained in the sequence. The sequence of 3 bases for 1 amino acid. Proteins ae responsible for certain characterics such as eye colour
How many stages are there in mitosis:
7
Arrange the stages of mitosis in order:
Interphase, prophase, prometaphase, metaphase, anaphase, telephase, cytokynesis.
What happens at interphase:
- The DNA is copied
- The chromosomes are not visible
What happens at prophase:
-The chromosomes condense and can now be seen
What happens at prometaphase:
- The nucleus disappears
- The spindle fibres appear
what happens at metaphase:
The chromosomes align at the equator of the spindle
What happens at anaphase:
Spindle fibres full the chromotids apart to opposite ends of the cell
What happens at telephase:
A new nucleus membrane appears around each of the sets of chromosomes
What happens at cytokynesis:
- The cell starts to divide
- Two genetically identical daughter cells are formed
What is the result of mitosis:
The production of two genetically identical daughter cells
Where does mitosis happen:
- In all body cells
- In bacteria and other microorganisms
- In plants
What is the purpose of mitosis:
- To produce more cells (growth)
- To replace dead cells (repair)
- Asexual Reproduction
Define DNA replication:
The copying of a DNA molecule to obtain two identical DNA molecules
How does DNA replicate:
The DNA:
- Unwinds
- Seperates
- Complementary base pairing
- DNA winds into helical structure
What is the end product after DNA replication:
One strand of the original parental DNA
One new strand
What is DNA replication also known as:
Semi conservative replication
How many parents are required for asexual reproduction:
One
How many parents are required for sexual reproduction:
Two
Describe the genetic make up in asexual reproduction:
Offsprings are identical to each other and parents
Describe the genetic make up in sexual reproduction:
Prodcues a variety
Examples of asexual reproduction:
In fungi, bacteria, protoctista, plants and some animals
Examples of sexual reproduction:
In fungi, plants and animals
Ways in which plants can develop in asexual reproduction:
- Roots
- Stems
- Leaves
Define runners:
Overground arial stems which grow roots and develop into new plants
Define rhizomes:
An undergroud stem which grows through the soil and will periodically produce new roots above ground roots
Define tubers:
Underground swollen stem from which new plants may grow
Define bulbs:
Undergrond storage organ made from adapted leaves. New plants grow from it
Describe the process cutting:
- A small amount of the parent plant is removed
- The cutting then grows into an independent plant
Describe the process of micropropagation:
- Take a few cells or small parts from a plant (=cutting)
- Put them into culture medium
- Let them grow into many new plants
Why does plant cloning work:
- Plants contain meristem cells which are actively undergoing mitosis
- These cells are totipotent and can change into all different kinds of plants
Why clone plants:
- To produce genetically identical copies of a plant with desirable characteristics
- To quickly produce many mature plants
- To produce plants in the abscence of pollenators
- To make copies of plants that have been genetically modified
- To produce plants that do not grow easily from seeds
Describe embroyo splitting:
1) Sperm is taken from the bull from a high yield herd
2) The cow is artifically inseminated with the sperm
3) Zygote forms anddevelops into early embroyo
4) Embroyo is split into several smaller embroyos
5) The embroyos are placed in surrogate mothers
6) Genetically indentical calves were born
Describe reproductive cloning:
1) Nucleus of sheep A is isolated
2) Nucleus is removed from sheep B
3) Mild electric shock takes place
4) Mitosis produces an embroyo
5) This is implanted in surrogate mother
6) Clone of Sheep A is made
Arguments FOR animal cloning:
- Prevent extinction
- Boost agriculture
- Lots of milk
- Personal attachment
- To clone genetically engineered animals
- Organ donors
- Use clones for medical trials
