Genetic Crosses and Heredity

Question 1

All body cells except reproductive cells are?

Answer 1

somatic cells

Question 2

Somatic cells include? (name 3).

Answer 2

cheek, blood, muscle

Question 3

Definition of gametes?

Answer 3

are haploid cells that are capable of fusion

Question 4

Definition of fertilisation?

Answer 4

is the fusion of a male gamete with a female gamete

Question 5

Definition of allele?

Answer 5

form of a gene

Question 6

What is the locus of a gene?

Answer 6

is it’s position on a chromosome

Question 7

What does dominant mean in terms of alleles?

Answer 7

the allele that prevents the recessive allele from being expressed

Question 8

What does recessive mean in terms of alleles?

Answer 8

the allele is masked by the dominant allele

Question 9

Definition of heredity?

Answer 9

the passing on of traits/features from parent to offspring by means of genes

Question 10

What is a gene?

Answer 10

a section of DNA that codes for a particular protein

Question 11

Where are genes located?

Answer 11

on chromosomes

Question 12

Chromosomes are made up of what two things?

Answer 12

DNA and protein

Question 13

How many genes do we get from each parent?

Answer 13

One

Question 14

Name two types of genes.

Answer 14

Dominant and recessive

Question 15

Definition of genotype?

Answer 15

the genetic make-up of an organism (the genes that are present)

Question 16

Definition of phenotype?

Answer 16

the physical make-up, or appearance, of an organism

Question 17

What does progeny mean?

Answer 17

refers to offspring that are produced

Question 18

Difference between homozygous and heterozygous?

Answer 18

• homozygous: alleles are identical for a trait
• heterozygous: the alleles are different

Question 19

What does a punnet square show?

Answer 19

the ratio of genotypes of progeny in a genetic cross

Question 20

What does incomplete dominance mean?

Answer 20

neither allele is dominant or recessive with respect to each other

Question 21

Definition of a pedigree?

Answer 21

(a diagram showing ) the genetic history of a group of related individuals

Question 22

Non-sex chromosomes are called?

Answer 22

autosomes

Question 23

Nucleus of each human somatic cell has how many chromosomes? How are they split?

Answer 23

46 total,
44 non-sex chromosomes = autosomes,
2 sex chromosomes

Question 24

Give an example of a gender-neutral feature.

Answer 24

skin colour

Question 25

Two sex chromosomes are called?

Answer 25

X and Y

Question 26

Is X or Y chromosome longer?

Answer 26

X

Question 27

XX = what gender? XY = what gender?

Answer 27

female male

Question 28

Do male or female determine gender of child?

Answer 28

male

Question 29

Name some species where the pattern of determination is the reverse.

Answer 29

butterflies, moths, birds

Question 30

George Mendel is known as the?

Answer 30

'father of genetics'

Question 31

'Father of genetics' is who?

Answer 31

George Mendel

Question 32

What did George Mendel examine?

Answer 32

pea plants on seven characteristics

Question 33

Where is Mendel from?

Answer 33

Austria

Question 34

Describe what exactly Mendel did/found out.

Answer 34

he got purple and white pea plants the purple flowers self-pollinated and so did the white flowers he made sure he had true breeding plants by looking at many generations produced (purple only produced purple, white only produced white)

Question 35

Mendel's first law is called?

Answer 35

the law of segregation

Question 36

The law of segregation refers to which law?

Answer 36

first

Question 37

Describe Mendel's first law/law of segregation.

Answer 37

each trait is controlled by a pair of factors these factors separate during the formation of gametes each gamete contains only one factor per trait

Question 38

Mendel's first law was based on?

Answer 38

examining one trait only

Question 39

Difference between monohybrid and dihybrid cross?

Answer 39

monohybrid: involves study of a single characteristic dihybrid: involves the study of two characteristics

Question 40

Describe Mendel's second law.

Answer 40

each member of 1 pair of alleles can combine with either member of another pair

Question 41

What's the name of Mendel's second law?

Answer 41

law of independent assortment

Question 42

The law of independent assortment refers to which of Mendal's laws?

Answer 42

second

Question 43

Definition of linkage?

Answer 43

the genes are located on the same chromosome

Question 44

Definition of sex linkage?

Answer 44

a characteristic is controlled by a gene on an X chromosome

Question 45

Does X or Y carry more genes?

Answer 45

X

Question 46

Give two examples of sex-linked characteristics.

Answer 46

colour blindness, haemophilia

Question 47

What is haemophilia?

Answer 47

inability to clot blood

Question 48

What's colour blindness?

Answer 48

typically we see red, green and blue but being colour blind means inability to distinguish between red from green

Question 49

For a female to be colour blind she needs?

Answer 49

two copies of the recessive allele

Question 50

For a male to be colour blind he needs?

Answer 50

one recessive allele

Question 51

Give two points on non-nuclear inheritance.

Answer 51

most of the DNA (and genes) in a cell is located in the nucleus small loops of DNA in mitochondria and chloroplasts

Question 52

Dihybrid cross crossing heterozygous x heterozygous gives what ratio?

Answer 52

9:3:3:1

Question 53

Dihybrid cross crossing heterozygous x homozygous gives what ratio?

Answer 53

1:1:1:1