Inheritance Flashcards
Define genetics:
- the study of heredity and variation in living things.
What are polygenic traits?
Polygenic traits -> are characteristics controlled by many genes
Hereditary characteristics are transferred by ___
- Hereditary characteristics are transferred by gametes
Sperm + egg = zygote -> organism
What do organisms inherit from parent?
- Each organism inherits characteristics from parent that makes it that type of organism e.g: a dog/cat
- each organism also inherits characteristics that make it unique.
What is a genome?
- a complete set of genes
All the DNA that codes for proteins ->
All the DNA that codes for proteins -> traits
Each somatic cell has __ ___ ___ __ ___
Each somatic cell has a complete set of instructions (genes)
What somatic cell doesn’t have a complete set of instructions ?
- a red blood cell
Are all parts of the gene activated in certain cells to synthesis proteins?
- Only parts of the gene activated in certain cells to synthesis particular proteins for that cell.
Who was the father of genetics?
- what did he do?
Gregor Mendel -> the father of genetics
- worked at a monetary and taught high school
How did Gregor Mendel become interested in genetics?
- he tended a monetary garden
- grew peas and became interested in the traits that were expressed in different generations in peas.
- through this, he formulated the basic laws of genetics.
What does every living things have?
- a set of characteristics inherited from it’s parents
Why did Mendel study peas?
-grow quickly -> results obtained quickly.
-easily identifiable traits
-peas produce a large number of offspring -> which make results easier to verify
-naturally self-pollinating -> could control the crosses by hand
What are the 7 contrasting characteristics?
- Tall/short
- smooth/wrinkled seeds
- yellow/green seeds
- inflated/constricted pods
- purple/white flowers
- axial/terminal flowers
How would Mendel manually cross pollinate?
- cut the anthers off one flower and dusted the pollen from anthers onto the stigma of another flower.
What is “true breeding”?
- any crosses performed will result in offspring of the same phenotype -> which indicates that the organism is homogeneous for every gene.
Define Monohybrid Cross:
- a cross between organisms that differ in one respect.
Explain the P1 cross:
- Mendel Cross-pollinated two plants with differing traits (tall and short)
. -> is the P1 generation - then collected and sowed the seeds (offspring of the crosses)
- this generation was called the F1 generation and they all grew tall.
Explain the F1 Cross:
- he allowed the F1 Generation to Self pollinate creating F2 Generation
- the F2 Generation, the characteristics of shortness reappeared 25% of the time whilst the tall appeared 75% of the time
- meaning the shortness had not completely disappeared.
Define complete dominance:
- a characteristics that is fully expressed in the phenotype of heterozygous organism is the dominant allele
- the characteristics that is masked is the recessive allele and will only be present in the phenotype when homozygous.
What were Mendels three conclusions?
- Mendels law of segregation.
- Mendels law of dominance
- Mendels law of independent assortment
Describe Mendels law of segregation.
- During meiosis, allele pairs separate so that gametes have a single allele for each characteristic.
Describe Mendels law of dominance.
- In a Cross of parents that are “pure” for contrasting traits, only the dominant trait will appear in the phenotype of offspring.
Describe Mendels law of Independent assortment
- the alleles of different genes segregate randomly and independently of one another during meiosis.
What is a “double Merle”?
- “Double Merle” is when a dog is homozygous for a gene. These dogs are blind, deaf or have other health complications.
What is sickle-cell disease?
- is it autosomal or recessive
- a group of blood disorders typically inherited from a persons parent.
- sickle-cell has an autosomal recessive pattern.
Explain somatic cells of biological male:
- 44 atutosomes
- XY gonosomes
Explain somatic cells of biological female:
- 44 Autonomes
- XX gonosomes
Explain the gametes of biological female:
- 22 autosomes
- X gonosome
Explain the gametes of biological male:
- 22 autosomes
- X or Y gonosomes
What are gonosomes and what do they do?
- control the sex of a person.
- carry other genes -> sex-linked genes
Y chromosome -> size and what is does.
Y chromosome is small and carries almost no other genes apart from those coding for “maleness”
X chromosome -> size and what it does.
X chromosome is large and carries many other genes including those coding for “femaleness”
Describe Red-Green colourblindness:
- can’t determine between various hues of red and green.
- absence of photo-pigment on retinal clones
- Recessive gene carried on X chromosome
Describe Haemophilia:
- inability to clot blood properly -> frequent excessive bleeding and bruise easily.
- located on X chromosome and is recessive.
What does a genetic counsellor do?
- Genetic counsellors are health professionals who study family and medical histories to analyse inheritance patterns and risks of problems occurring.
What is a family tree?
-what can it predict
-A family tree shows the genotype and phenotype of several generations of individuals in a family (shows carriers aswell)
- can predict if a couple is likely to pass on genetic disorders.
