Inheritance

Question 1

Define genetics:

Answer 1

• the study of heredity and variation in living things.

Question 2

What are polygenic traits?

Answer 2

Polygenic traits -> are characteristics controlled by many genes

Question 3

Hereditary characteristics are transferred by ___

Answer 3

• Hereditary characteristics are transferred by gametes

Sperm + egg = zygote -> organism

Question 4

What do organisms inherit from parent?

Answer 4

• 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.

Question 5

What is a genome?

Answer 5

• a complete set of genes

Question 6

All the DNA that codes for proteins ->

Answer 6

All the DNA that codes for proteins -> traits

Question 7

Each somatic cell has __ ___ ___ __ ___

Answer 7

Each somatic cell has a complete set of instructions (genes)

Question 8

What somatic cell doesn’t have a complete set of instructions ?

Answer 8

• a red blood cell

Question 9

Are all parts of the gene activated in certain cells to synthesis proteins?

Answer 9

• Only parts of the gene activated in certain cells to synthesis particular proteins for that cell.

Question 10

Who was the father of genetics?
- what did he do?

Answer 10

Gregor Mendel -> the father of genetics

• worked at a monetary and taught high school

Question 11

How did Gregor Mendel become interested in genetics?

Answer 11

• 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.

Question 12

What does every living things have?

Answer 12

• a set of characteristics inherited from it’s parents

Question 13

Why did Mendel study peas?

Answer 13

-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

Question 14

What are the 7 contrasting characteristics?

Answer 14

• Tall/short
• smooth/wrinkled seeds
• yellow/green seeds
• inflated/constricted pods
• purple/white flowers
• axial/terminal flowers

Question 15

How would Mendel manually cross pollinate?

Answer 15

• cut the anthers off one flower and dusted the pollen from anthers onto the stigma of another flower.

Question 16

What is “true breeding”?

Answer 16

• any crosses performed will result in offspring of the same phenotype -> which indicates that the organism is homogeneous for every gene.

Question 17

Define Monohybrid Cross:

Answer 17

• a cross between organisms that differ in one respect.

Question 18

Explain the P1 cross:

Answer 18

• 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.

Question 19

Explain the F1 Cross:

Answer 19

• 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.

Question 20

Define complete dominance:

Answer 20

• occurs when one allele (the dominant allele) completely masks the effect of another allele (the recessive allele) in a heterozygous individual, meaning the dominant trait is fully expressed in the phenotype, while the recessive trait is not visible.

Question 21

What were Mendels three conclusions?

Answer 21

1. Mendels law of segregation.
2. Mendels law of dominance
3. Mendels law of independent assortment

Question 22

Describe Mendels law of segregation.

Answer 22

• During meiosis, allele pairs separate so that gametes have a single allele for each characteristic.

Question 23

Describe Mendels law of dominance.

Answer 23

• In a Cross of parents that are “pure” for contrasting traits, only the dominant trait will appear in the phenotype of offspring.

Question 24

Describe Mendels law of Independent assortment

Answer 24

• the alleles of different genes segregate randomly and independently of one another during meiosis.

Question 25

What is a "double Merle"?

Answer 25

- "Double Merle" is when a dog is homozygous for a gene. These dogs are blind, deaf or have other health complications.

Question 26

What is sickle-cell disease? - is it autosomal or recessive

Answer 26

- a group of blood disorders typically inherited from a persons parent. - sickle-cell has an autosomal recessive pattern.

Question 27

Explain somatic cells of biological male:

Answer 27

- 44 atutosomes - XY gonosomes

Question 28

Explain somatic cells of biological female:

Answer 28

- 44 Autonomes - XX gonosomes

Question 29

Explain the gametes of biological female:

Answer 29

- 22 autosomes - X gonosome

Question 30

Explain the gametes of biological male:

Answer 30

- 22 autosomes - X or Y gonosomes

Question 31

What are gonosomes and what do they do?

Answer 31

- control the sex of a person. - carry other genes -> sex-linked genes

Question 32

Y chromosome -> size and what is does.

Answer 32

Y chromosome is small and carries almost no other genes apart from those coding for "maleness"

Question 33

X chromosome -> size and what it does.

Answer 33

X chromosome is large and carries many other genes including those coding for "femaleness"

Question 34

Describe Red-Green colourblindness:

Answer 34

- can’t determine between various hues of red and green. - absence of photo-pigment on retinal clones - Recessive gene carried on X chromosome

Question 35

Describe Haemophilia:

Answer 35

- inability to clot blood properly -> frequent excessive bleeding and bruise easily. - located on X chromosome and is recessive.

Question 36

What does a genetic counsellor do?

Answer 36

- Genetic counsellors are health professionals who study family and medical histories to analyse inheritance patterns and risks of problems occurring.

Question 37

What is a family tree? -what can it predict

Answer 37

-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.